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In which scenarios is it important to measure microampere?
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With the situation of finding a new multimeter, I found myself lost to the number of available devices on the market. For sure, to find the most suitable device I have to set some requirements. While comparing them, I came to the following point and by this to my question:
Most pro devices have only ampere range with a solution of 0.001 A, while semi/hobby devices have ranges for milliampere and even micro-ampere. I saw device reviews on YouTube, where the presenter complained about missing micro-ampere range. While another person on YouTube told the audience that milliampere range is sufficient. So, here my question to the experts:
What kind of scenarios require a measurement of micro-amperes?
For example: Looking at a data sheet an AND gate has "input leakage current" and supply current in micro-ampere range, but when is it necessary to measure this tiny current?
Thanks for all helpful answers.
multimeter
edited 5 mins ago
mastov
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asked yesterday
Toby N.
594
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up vote
10
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With the situation of finding a new multimeter, I found myself lost to the number of available devices on the market. For sure, to find the most suitable device I have to set some requirements. While comparing them, I came to the following point and by this to my question:
Most pro devices have only ampere range with a solution of 0.001 A, while semi/hobby devices have ranges for milliampere and even micro-ampere. I saw device reviews on YouTube, where the presenter complained about missing micro-ampere range. While another person on YouTube told the audience that milliampere range is sufficient. So, here my question to the experts:
What kind of scenarios require a measurement of micro-amperes?
For example: Looking at a data sheet an AND gate has "input leakage current" and supply current in micro-ampere range, but when is it necessary to measure this tiny current?
Thanks for all helpful answers.
multimeter
edited 5 mins ago
mastov
1073
asked yesterday
Toby N.
594
New contributor
Toby N. is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
4
Have you ever heard of devices that run for 80000 hours with a 2000mAh battery?
– PlasmaHH
yesterday
3
Not an answer, but it's worth noting that the test equipment company Keithley makes ammeters with a resolution of 10 fA, and Keysight's B2980A series has a resolution of 0.01 fA, which is frankly quite ridiculous.
– Felthry
23 hours ago
3
@Felthry: I had my hands on equipment that would count electrons. And it had to be recalibrated afterwards...
– PlasmaHH
23 hours ago
2
Dave Jones, from the EEVblog, also had this problem and developed the uCurrent.
– Jeroen3
23 hours ago
@PlasmaHH Yes, of course. But for developing and/or repairing, a SMU device would be much more appropriated - see also answer from Shamatam. So do you think it really makes sense to have a multimeter with µA support? In case you work with such devices. Just a question, I'm not saying that such multimeter is useless.
– Toby N.
20 hours ago
 |Â
show 3 more comments
up vote
10
down vote
favorite
up vote
10
down vote
favorite
With the situation of finding a new multimeter, I found myself lost to the number of available devices on the market. For sure, to find the most suitable device I have to set some requirements. While comparing them, I came to the following point and by this to my question:
Most pro devices have only ampere range with a solution of 0.001 A, while semi/hobby devices have ranges for milliampere and even micro-ampere. I saw device reviews on YouTube, where the presenter complained about missing micro-ampere range. While another person on YouTube told the audience that milliampere range is sufficient. So, here my question to the experts:
What kind of scenarios require a measurement of micro-amperes?
For example: Looking at a data sheet an AND gate has "input leakage current" and supply current in micro-ampere range, but when is it necessary to measure this tiny current?
Thanks for all helpful answers.
multimeter
edited 5 mins ago
mastov
1073
asked yesterday
Toby N.
594
New contributor
Toby N. is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
With the situation of finding a new multimeter, I found myself lost to the number of available devices on the market. For sure, to find the most suitable device I have to set some requirements. While comparing them, I came to the following point and by this to my question:
Most pro devices have only ampere range with a solution of 0.001 A, while semi/hobby devices have ranges for milliampere and even micro-ampere. I saw device reviews on YouTube, where the presenter complained about missing micro-ampere range. While another person on YouTube told the audience that milliampere range is sufficient. So, here my question to the experts:
What kind of scenarios require a measurement of micro-amperes?
For example: Looking at a data sheet an AND gate has "input leakage current" and supply current in micro-ampere range, but when is it necessary to measure this tiny current?
Thanks for all helpful answers.
multimeter
multimeter
edited 5 mins ago
mastov
1073
asked yesterday
Toby N.
594
New contributor
Toby N. is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 5 mins ago
mastov
1073
asked yesterday
Toby N.
594
New contributor
Toby N. is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 5 mins ago
mastov
1073
edited 5 mins ago
mastov
1073
edited 5 mins ago
mastov
1073
1073
asked yesterday
Toby N.
594
New contributor
Toby N. is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked yesterday
Toby N.
594
asked yesterday
Toby N.
594
594
New contributor
Toby N. is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Toby N. is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Toby N. is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
4
Have you ever heard of devices that run for 80000 hours with a 2000mAh battery?
– PlasmaHH
yesterday
3
Not an answer, but it's worth noting that the test equipment company Keithley makes ammeters with a resolution of 10 fA, and Keysight's B2980A series has a resolution of 0.01 fA, which is frankly quite ridiculous.
– Felthry
23 hours ago
3
@Felthry: I had my hands on equipment that would count electrons. And it had to be recalibrated afterwards...
– PlasmaHH
23 hours ago
2
Dave Jones, from the EEVblog, also had this problem and developed the uCurrent.
– Jeroen3
23 hours ago
@PlasmaHH Yes, of course. But for developing and/or repairing, a SMU device would be much more appropriated - see also answer from Shamatam. So do you think it really makes sense to have a multimeter with µA support? In case you work with such devices. Just a question, I'm not saying that such multimeter is useless.
– Toby N.
20 hours ago
 |Â
show 3 more comments
4
Have you ever heard of devices that run for 80000 hours with a 2000mAh battery?
– PlasmaHH
yesterday
3
Not an answer, but it's worth noting that the test equipment company Keithley makes ammeters with a resolution of 10 fA, and Keysight's B2980A series has a resolution of 0.01 fA, which is frankly quite ridiculous.
– Felthry
23 hours ago
3
@Felthry: I had my hands on equipment that would count electrons. And it had to be recalibrated afterwards...
– PlasmaHH
23 hours ago
2
Dave Jones, from the EEVblog, also had this problem and developed the uCurrent.
– Jeroen3
23 hours ago
@PlasmaHH Yes, of course. But for developing and/or repairing, a SMU device would be much more appropriated - see also answer from Shamatam. So do you think it really makes sense to have a multimeter with µA support? In case you work with such devices. Just a question, I'm not saying that such multimeter is useless.
– Toby N.
20 hours ago
4
4
Have you ever heard of devices that run for 80000 hours with a 2000mAh battery?
– PlasmaHH
yesterday
Have you ever heard of devices that run for 80000 hours with a 2000mAh battery?
– PlasmaHH
yesterday
3
3
Not an answer, but it's worth noting that the test equipment company Keithley makes ammeters with a resolution of 10 fA, and Keysight's B2980A series has a resolution of 0.01 fA, which is frankly quite ridiculous.
– Felthry
23 hours ago
Not an answer, but it's worth noting that the test equipment company Keithley makes ammeters with a resolution of 10 fA, and Keysight's B2980A series has a resolution of 0.01 fA, which is frankly quite ridiculous.
– Felthry
23 hours ago
3
3
@Felthry: I had my hands on equipment that would count electrons. And it had to be recalibrated afterwards...
– PlasmaHH
23 hours ago
@Felthry: I had my hands on equipment that would count electrons. And it had to be recalibrated afterwards...
– PlasmaHH
23 hours ago
2
2
Dave Jones, from the EEVblog, also had this problem and developed the uCurrent.
– Jeroen3
23 hours ago
Dave Jones, from the EEVblog, also had this problem and developed the uCurrent.
– Jeroen3
23 hours ago
@PlasmaHH Yes, of course. But for developing and/or repairing, a SMU device would be much more appropriated - see also answer from Shamatam. So do you think it really makes sense to have a multimeter with µA support? In case you work with such devices. Just a question, I'm not saying that such multimeter is useless.
– Toby N.
20 hours ago
@PlasmaHH Yes, of course. But for developing and/or repairing, a SMU device would be much more appropriated - see also answer from Shamatam. So do you think it really makes sense to have a multimeter with µA support? In case you work with such devices. Just a question, I'm not saying that such multimeter is useless.
– Toby N.
20 hours ago
 |Â
show 3 more comments
6 Answers
6
active
oldest
votes
up vote
13
down vote
accepted
One of a line of products I worked with and designed for was a smart payphone; think a microcontroller that operates as if it were a payphone.
These had to operate on an ordinary telephone loop, with a guaranteed 20mA supply (but not guaranteed to be higher); in the on-hook condition the unit was permitted only a few microamps of leakage current as the central office would otherwise detect a line fault.
In response to the comment on leakage; due to the harsh environment (outside in very hot, very cold and high humidity) the boards within the payphone housing were conformally coated and used moisture sealed connectors.
These units clearly needed to be tested as the difference between on-hook and off-hook current draw is order of magnitude different so confirming just a few microamps on-hook was quite important.
Another application is in new, really low power microcontrollers (typical part linked) where I would want to confirm the actual current draw in the various modes of operation and some of those modes are in the microamp range (or less).
Lots of possible applications, this is just a couple.
answered yesterday
Peter Smith
13k11237
Telephone example is pretty surprising. At 50V, even 5 megohms would produce "a few" (10 in this case) microamps of current. I'd be surprised humidity around joints didn't produce that effect, or even 10km of cable insulation.
– abligh
20 hours ago
The telephone loop is ~48VAC. Not sure what the back-of-the-envelope leakage is for that...
– jdv
18 hours ago
@Peter Smith: It looks like community votes for your answer. Thank you for giving those examples and sharing the link to the low power microcontroller. It gives a good impression about where to measure µA ...
– Toby N.
18 hours ago
2
@jdv - Phone supply is -48v DC not AC
– Jim Mack
18 hours ago
I will mark this as final answer, because it has the most votes. It does not mean that all the other answers are wrong. Thank you to all for the answers and comments!
– Toby N.
5 hours ago
 |Â
show 2 more comments
up vote
12
down vote
A lot of battery-operated devices need to optimize for power consumption, and µA currents are frequently involved (sometimes even nA).
To give an example, consider wireless remotes. They may have just a 3V, 200mAh battery. If you want this remote to work 10 years without necessitating battery change, that's just 20 mAh/year. Or 0.054 mAh/day, or 0.0022 mAh / hour. We cancel the hours and it's a shy more than 2µA continuous idle drain. A lot of contemporary micros and RTCs are way better than this, but you need to measure your production run to verify the device works as intended.
You'd say "isn't battery lifetime dependent on the number of operations of the remote" - well, it could, but the idle consumption may be more significant. The wireless transmitter and the MCU inside the remote may consume 10mA for a brief period when operated. Say less than a second. So that's 10mA but for a very short period, so the energy consumed from the battery is quite minimal. In contrast, just the 2µA idle drain for a whole day requires more than 16 times more energy.
answered 23 hours ago
anrieff
1,568823
add a comment |Â
up vote
7
down vote
First, your assumption that professional multimeters don't have a microamp scale is wrong. A Fluke 287, for instance, will happily measure microamps. The Fluke 116 only has a microamp scale for current measurements.
A lot of professional multimeters are designed for specific use cases. The aforementioned Fluke 116 is targeted at HVAC systems, where (apparently) the only currents they need to measure are from flame sensors. A high-end model like the 287 can do everything. I used one to measure reference currents in the 0-20 uA range back when I was working on flash memory process development. For battery-powered systems, microamps are important. But for most use cases, you don't need the microamp scale, so you don't pay extra for one.
answered 18 hours ago
Adam Haun
16.6k33074
You're correct. After more research, I realized that Fluke has multimeters specific to the use case. As you said, Fluke 116 with only µA range. It was confusing me, that some multimeters (for example UNI-T) just come with µA almost by default and in the professional area, this range is not available on every device.
– Toby N.
18 hours ago
The UNI-T is an order of magnitude cheaper than the Fluke. The specs are probably a lot worse, and quality control will be as well. Hobbyists aren't too picky about that stuff, but if you're a company with millions of dollars on the line, you're willing to pay for quality guarantees.
– Adam Haun
16 hours ago
add a comment |Â
up vote
6
down vote
When you are developing low-power devices, every nanoAmpere is worth to be saved. For example, when using a CR2032 coin battery you have around 200mAh of capacity. Once I developed a device powered by one of those batteries and I had to check that the microcontroller went to sleep mode (0.6uA) most of the time. Also need to check that when active, the current consumption was in the range of 10uA. In addition, I had to check that sum of every component in the PCB (in their low power mode) matched the sum of the quiescent current stated by their datasheets.
In summary, if you want to get the most of your power source, and be sure that you are handling your hardware/software you have to measure low-power performance of your components, and usually this rate is given in uA or nA.
answered 22 hours ago
GVelascoh
614
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GVelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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1
Thanks for this answer, it gives a good example and it is easy to understand. I like it with all the other answers here.
– Toby N.
18 hours ago
add a comment |Â
up vote
3
down vote
Often when performing characterization and modeling of semiconductor devices, leakage currents (which are critical to creating a useful and accurate model) will fall in the micro-ampere range. Typically these measurements would be performed with a Precision Source-Measure Unit (SMU for short). Such measurements are also commonly used in technology development to evaluate the fundamental performance of a given semiconductor process.
answered yesterday
Shamtam
2,0981022
Good point with SMU. For hobby electronic (even dealing with low current devices) it might be not the right measurement device from a cost perspective. So in your personal opinion: Is a multimeter a good alternative or do you think mA range is sufficient? See also the answer of Adam Haun and Peter Smith - interesting stuff with focus on low current.
– Toby N.
17 hours ago
It depends on the application in question. Other answers highlight some specific examples of where the mA range is just not sufficient (e.g. production testing of low-power battery-driven circuits). If the multimeter has the accuracy and/or precision necessary for the measurement, then sure, it's fine. Perhaps it's even feasible to build a circuit using e.g. an instrumentation amplifier to convert a $mu$A range current to something detectable by a cheaper multimeter reliably. Again, it's very application specific.
– Shamtam
14 hours ago
add a comment |Â
up vote
0
down vote
When operating an electron microscope, it is often desirable to know the beam current to the resolution of a few picoamps. Beam currents are small because the goal of an electron microscope is to focus a narrow (and thus low current) beam of electrons on the sample, in order to have the beam interact with small features.
This is accomplished by connecting an ammeter between an electrically isolated sample stage and the microscope ground. Such an ammeter must, of course, be able to measure in the range of currents used by the instrument.
answered 12 hours ago
Owen
60036
add a comment |Â
6 Answers
6
active
oldest
votes
6 Answers
6
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
13
down vote
accepted
One of a line of products I worked with and designed for was a smart payphone; think a microcontroller that operates as if it were a payphone.
These had to operate on an ordinary telephone loop, with a guaranteed 20mA supply (but not guaranteed to be higher); in the on-hook condition the unit was permitted only a few microamps of leakage current as the central office would otherwise detect a line fault.
In response to the comment on leakage; due to the harsh environment (outside in very hot, very cold and high humidity) the boards within the payphone housing were conformally coated and used moisture sealed connectors.
These units clearly needed to be tested as the difference between on-hook and off-hook current draw is order of magnitude different so confirming just a few microamps on-hook was quite important.
Another application is in new, really low power microcontrollers (typical part linked) where I would want to confirm the actual current draw in the various modes of operation and some of those modes are in the microamp range (or less).
Lots of possible applications, this is just a couple.
answered yesterday
Peter Smith
13k11237
Telephone example is pretty surprising. At 50V, even 5 megohms would produce "a few" (10 in this case) microamps of current. I'd be surprised humidity around joints didn't produce that effect, or even 10km of cable insulation.
– abligh
20 hours ago
The telephone loop is ~48VAC. Not sure what the back-of-the-envelope leakage is for that...
– jdv
18 hours ago
@Peter Smith: It looks like community votes for your answer. Thank you for giving those examples and sharing the link to the low power microcontroller. It gives a good impression about where to measure µA ...
– Toby N.
18 hours ago
2
@jdv - Phone supply is -48v DC not AC
– Jim Mack
18 hours ago
I will mark this as final answer, because it has the most votes. It does not mean that all the other answers are wrong. Thank you to all for the answers and comments!
– Toby N.
5 hours ago
 |Â
show 2 more comments
up vote
13
down vote
accepted
One of a line of products I worked with and designed for was a smart payphone; think a microcontroller that operates as if it were a payphone.
These had to operate on an ordinary telephone loop, with a guaranteed 20mA supply (but not guaranteed to be higher); in the on-hook condition the unit was permitted only a few microamps of leakage current as the central office would otherwise detect a line fault.
In response to the comment on leakage; due to the harsh environment (outside in very hot, very cold and high humidity) the boards within the payphone housing were conformally coated and used moisture sealed connectors.
These units clearly needed to be tested as the difference between on-hook and off-hook current draw is order of magnitude different so confirming just a few microamps on-hook was quite important.
Another application is in new, really low power microcontrollers (typical part linked) where I would want to confirm the actual current draw in the various modes of operation and some of those modes are in the microamp range (or less).
Lots of possible applications, this is just a couple.
answered yesterday
Peter Smith
13k11237
Telephone example is pretty surprising. At 50V, even 5 megohms would produce "a few" (10 in this case) microamps of current. I'd be surprised humidity around joints didn't produce that effect, or even 10km of cable insulation.
– abligh
20 hours ago
The telephone loop is ~48VAC. Not sure what the back-of-the-envelope leakage is for that...
– jdv
18 hours ago
@Peter Smith: It looks like community votes for your answer. Thank you for giving those examples and sharing the link to the low power microcontroller. It gives a good impression about where to measure µA ...
– Toby N.
18 hours ago
2
@jdv - Phone supply is -48v DC not AC
– Jim Mack
18 hours ago
I will mark this as final answer, because it has the most votes. It does not mean that all the other answers are wrong. Thank you to all for the answers and comments!
– Toby N.
5 hours ago
 |Â
show 2 more comments
up vote
13
down vote
accepted
up vote
13
down vote
accepted
One of a line of products I worked with and designed for was a smart payphone; think a microcontroller that operates as if it were a payphone.
These had to operate on an ordinary telephone loop, with a guaranteed 20mA supply (but not guaranteed to be higher); in the on-hook condition the unit was permitted only a few microamps of leakage current as the central office would otherwise detect a line fault.
In response to the comment on leakage; due to the harsh environment (outside in very hot, very cold and high humidity) the boards within the payphone housing were conformally coated and used moisture sealed connectors.
These units clearly needed to be tested as the difference between on-hook and off-hook current draw is order of magnitude different so confirming just a few microamps on-hook was quite important.
Another application is in new, really low power microcontrollers (typical part linked) where I would want to confirm the actual current draw in the various modes of operation and some of those modes are in the microamp range (or less).
Lots of possible applications, this is just a couple.
answered yesterday
Peter Smith
13k11237
One of a line of products I worked with and designed for was a smart payphone; think a microcontroller that operates as if it were a payphone.
These had to operate on an ordinary telephone loop, with a guaranteed 20mA supply (but not guaranteed to be higher); in the on-hook condition the unit was permitted only a few microamps of leakage current as the central office would otherwise detect a line fault.
In response to the comment on leakage; due to the harsh environment (outside in very hot, very cold and high humidity) the boards within the payphone housing were conformally coated and used moisture sealed connectors.
These units clearly needed to be tested as the difference between on-hook and off-hook current draw is order of magnitude different so confirming just a few microamps on-hook was quite important.
Another application is in new, really low power microcontrollers (typical part linked) where I would want to confirm the actual current draw in the various modes of operation and some of those modes are in the microamp range (or less).
Lots of possible applications, this is just a couple.
answered yesterday
Peter Smith
13k11237
edited 6 hours ago
answered yesterday
Peter Smith
13k11237
answered yesterday
Peter Smith
13k11237
answered yesterday
Peter Smith
13k11237
13k11237
Telephone example is pretty surprising. At 50V, even 5 megohms would produce "a few" (10 in this case) microamps of current. I'd be surprised humidity around joints didn't produce that effect, or even 10km of cable insulation.
– abligh
20 hours ago
The telephone loop is ~48VAC. Not sure what the back-of-the-envelope leakage is for that...
– jdv
18 hours ago
@Peter Smith: It looks like community votes for your answer. Thank you for giving those examples and sharing the link to the low power microcontroller. It gives a good impression about where to measure µA ...
– Toby N.
18 hours ago
2
@jdv - Phone supply is -48v DC not AC
– Jim Mack
18 hours ago
I will mark this as final answer, because it has the most votes. It does not mean that all the other answers are wrong. Thank you to all for the answers and comments!
– Toby N.
5 hours ago
 |Â
show 2 more comments
Telephone example is pretty surprising. At 50V, even 5 megohms would produce "a few" (10 in this case) microamps of current. I'd be surprised humidity around joints didn't produce that effect, or even 10km of cable insulation.
– abligh
20 hours ago
The telephone loop is ~48VAC. Not sure what the back-of-the-envelope leakage is for that...
– jdv
18 hours ago
@Peter Smith: It looks like community votes for your answer. Thank you for giving those examples and sharing the link to the low power microcontroller. It gives a good impression about where to measure µA ...
– Toby N.
18 hours ago
2
@jdv - Phone supply is -48v DC not AC
– Jim Mack
18 hours ago
I will mark this as final answer, because it has the most votes. It does not mean that all the other answers are wrong. Thank you to all for the answers and comments!
– Toby N.
5 hours ago
Telephone example is pretty surprising. At 50V, even 5 megohms would produce "a few" (10 in this case) microamps of current. I'd be surprised humidity around joints didn't produce that effect, or even 10km of cable insulation.
– abligh
20 hours ago
Telephone example is pretty surprising. At 50V, even 5 megohms would produce "a few" (10 in this case) microamps of current. I'd be surprised humidity around joints didn't produce that effect, or even 10km of cable insulation.
– abligh
20 hours ago
The telephone loop is ~48VAC. Not sure what the back-of-the-envelope leakage is for that...
– jdv
18 hours ago
The telephone loop is ~48VAC. Not sure what the back-of-the-envelope leakage is for that...
– jdv
18 hours ago
@Peter Smith: It looks like community votes for your answer. Thank you for giving those examples and sharing the link to the low power microcontroller. It gives a good impression about where to measure µA ...
– Toby N.
18 hours ago
@Peter Smith: It looks like community votes for your answer. Thank you for giving those examples and sharing the link to the low power microcontroller. It gives a good impression about where to measure µA ...
– Toby N.
18 hours ago
2
2
@jdv - Phone supply is -48v DC not AC
– Jim Mack
18 hours ago
@jdv - Phone supply is -48v DC not AC
– Jim Mack
18 hours ago
I will mark this as final answer, because it has the most votes. It does not mean that all the other answers are wrong. Thank you to all for the answers and comments!
– Toby N.
5 hours ago
I will mark this as final answer, because it has the most votes. It does not mean that all the other answers are wrong. Thank you to all for the answers and comments!
– Toby N.
5 hours ago
 |Â
show 2 more comments
up vote
12
down vote
A lot of battery-operated devices need to optimize for power consumption, and µA currents are frequently involved (sometimes even nA).
To give an example, consider wireless remotes. They may have just a 3V, 200mAh battery. If you want this remote to work 10 years without necessitating battery change, that's just 20 mAh/year. Or 0.054 mAh/day, or 0.0022 mAh / hour. We cancel the hours and it's a shy more than 2µA continuous idle drain. A lot of contemporary micros and RTCs are way better than this, but you need to measure your production run to verify the device works as intended.
You'd say "isn't battery lifetime dependent on the number of operations of the remote" - well, it could, but the idle consumption may be more significant. The wireless transmitter and the MCU inside the remote may consume 10mA for a brief period when operated. Say less than a second. So that's 10mA but for a very short period, so the energy consumed from the battery is quite minimal. In contrast, just the 2µA idle drain for a whole day requires more than 16 times more energy.
answered 23 hours ago
anrieff
1,568823
add a comment |Â
up vote
12
down vote
A lot of battery-operated devices need to optimize for power consumption, and µA currents are frequently involved (sometimes even nA).
To give an example, consider wireless remotes. They may have just a 3V, 200mAh battery. If you want this remote to work 10 years without necessitating battery change, that's just 20 mAh/year. Or 0.054 mAh/day, or 0.0022 mAh / hour. We cancel the hours and it's a shy more than 2µA continuous idle drain. A lot of contemporary micros and RTCs are way better than this, but you need to measure your production run to verify the device works as intended.
You'd say "isn't battery lifetime dependent on the number of operations of the remote" - well, it could, but the idle consumption may be more significant. The wireless transmitter and the MCU inside the remote may consume 10mA for a brief period when operated. Say less than a second. So that's 10mA but for a very short period, so the energy consumed from the battery is quite minimal. In contrast, just the 2µA idle drain for a whole day requires more than 16 times more energy.
answered 23 hours ago
anrieff
1,568823
add a comment |Â
up vote
12
down vote
up vote
12
down vote
A lot of battery-operated devices need to optimize for power consumption, and µA currents are frequently involved (sometimes even nA).
To give an example, consider wireless remotes. They may have just a 3V, 200mAh battery. If you want this remote to work 10 years without necessitating battery change, that's just 20 mAh/year. Or 0.054 mAh/day, or 0.0022 mAh / hour. We cancel the hours and it's a shy more than 2µA continuous idle drain. A lot of contemporary micros and RTCs are way better than this, but you need to measure your production run to verify the device works as intended.
You'd say "isn't battery lifetime dependent on the number of operations of the remote" - well, it could, but the idle consumption may be more significant. The wireless transmitter and the MCU inside the remote may consume 10mA for a brief period when operated. Say less than a second. So that's 10mA but for a very short period, so the energy consumed from the battery is quite minimal. In contrast, just the 2µA idle drain for a whole day requires more than 16 times more energy.
answered 23 hours ago
anrieff
1,568823
A lot of battery-operated devices need to optimize for power consumption, and µA currents are frequently involved (sometimes even nA).
To give an example, consider wireless remotes. They may have just a 3V, 200mAh battery. If you want this remote to work 10 years without necessitating battery change, that's just 20 mAh/year. Or 0.054 mAh/day, or 0.0022 mAh / hour. We cancel the hours and it's a shy more than 2µA continuous idle drain. A lot of contemporary micros and RTCs are way better than this, but you need to measure your production run to verify the device works as intended.
You'd say "isn't battery lifetime dependent on the number of operations of the remote" - well, it could, but the idle consumption may be more significant. The wireless transmitter and the MCU inside the remote may consume 10mA for a brief period when operated. Say less than a second. So that's 10mA but for a very short period, so the energy consumed from the battery is quite minimal. In contrast, just the 2µA idle drain for a whole day requires more than 16 times more energy.
answered 23 hours ago
anrieff
1,568823
answered 23 hours ago
anrieff
1,568823
answered 23 hours ago
anrieff
1,568823
answered 23 hours ago
anrieff
1,568823
1,568823
add a comment |Â
add a comment |Â
up vote
7
down vote
First, your assumption that professional multimeters don't have a microamp scale is wrong. A Fluke 287, for instance, will happily measure microamps. The Fluke 116 only has a microamp scale for current measurements.
A lot of professional multimeters are designed for specific use cases. The aforementioned Fluke 116 is targeted at HVAC systems, where (apparently) the only currents they need to measure are from flame sensors. A high-end model like the 287 can do everything. I used one to measure reference currents in the 0-20 uA range back when I was working on flash memory process development. For battery-powered systems, microamps are important. But for most use cases, you don't need the microamp scale, so you don't pay extra for one.
answered 18 hours ago
Adam Haun
16.6k33074
You're correct. After more research, I realized that Fluke has multimeters specific to the use case. As you said, Fluke 116 with only µA range. It was confusing me, that some multimeters (for example UNI-T) just come with µA almost by default and in the professional area, this range is not available on every device.
– Toby N.
18 hours ago
The UNI-T is an order of magnitude cheaper than the Fluke. The specs are probably a lot worse, and quality control will be as well. Hobbyists aren't too picky about that stuff, but if you're a company with millions of dollars on the line, you're willing to pay for quality guarantees.
– Adam Haun
16 hours ago
add a comment |Â
up vote
7
down vote
First, your assumption that professional multimeters don't have a microamp scale is wrong. A Fluke 287, for instance, will happily measure microamps. The Fluke 116 only has a microamp scale for current measurements.
A lot of professional multimeters are designed for specific use cases. The aforementioned Fluke 116 is targeted at HVAC systems, where (apparently) the only currents they need to measure are from flame sensors. A high-end model like the 287 can do everything. I used one to measure reference currents in the 0-20 uA range back when I was working on flash memory process development. For battery-powered systems, microamps are important. But for most use cases, you don't need the microamp scale, so you don't pay extra for one.
answered 18 hours ago
Adam Haun
16.6k33074
You're correct. After more research, I realized that Fluke has multimeters specific to the use case. As you said, Fluke 116 with only µA range. It was confusing me, that some multimeters (for example UNI-T) just come with µA almost by default and in the professional area, this range is not available on every device.
– Toby N.
18 hours ago
The UNI-T is an order of magnitude cheaper than the Fluke. The specs are probably a lot worse, and quality control will be as well. Hobbyists aren't too picky about that stuff, but if you're a company with millions of dollars on the line, you're willing to pay for quality guarantees.
– Adam Haun
16 hours ago
add a comment |Â
up vote
7
down vote
up vote
7
down vote
First, your assumption that professional multimeters don't have a microamp scale is wrong. A Fluke 287, for instance, will happily measure microamps. The Fluke 116 only has a microamp scale for current measurements.
A lot of professional multimeters are designed for specific use cases. The aforementioned Fluke 116 is targeted at HVAC systems, where (apparently) the only currents they need to measure are from flame sensors. A high-end model like the 287 can do everything. I used one to measure reference currents in the 0-20 uA range back when I was working on flash memory process development. For battery-powered systems, microamps are important. But for most use cases, you don't need the microamp scale, so you don't pay extra for one.
answered 18 hours ago
Adam Haun
16.6k33074
First, your assumption that professional multimeters don't have a microamp scale is wrong. A Fluke 287, for instance, will happily measure microamps. The Fluke 116 only has a microamp scale for current measurements.
A lot of professional multimeters are designed for specific use cases. The aforementioned Fluke 116 is targeted at HVAC systems, where (apparently) the only currents they need to measure are from flame sensors. A high-end model like the 287 can do everything. I used one to measure reference currents in the 0-20 uA range back when I was working on flash memory process development. For battery-powered systems, microamps are important. But for most use cases, you don't need the microamp scale, so you don't pay extra for one.
answered 18 hours ago
Adam Haun
16.6k33074
answered 18 hours ago
Adam Haun
16.6k33074
answered 18 hours ago
Adam Haun
16.6k33074
answered 18 hours ago
Adam Haun
16.6k33074
16.6k33074
You're correct. After more research, I realized that Fluke has multimeters specific to the use case. As you said, Fluke 116 with only µA range. It was confusing me, that some multimeters (for example UNI-T) just come with µA almost by default and in the professional area, this range is not available on every device.
– Toby N.
18 hours ago
The UNI-T is an order of magnitude cheaper than the Fluke. The specs are probably a lot worse, and quality control will be as well. Hobbyists aren't too picky about that stuff, but if you're a company with millions of dollars on the line, you're willing to pay for quality guarantees.
– Adam Haun
16 hours ago
add a comment |Â
You're correct. After more research, I realized that Fluke has multimeters specific to the use case. As you said, Fluke 116 with only µA range. It was confusing me, that some multimeters (for example UNI-T) just come with µA almost by default and in the professional area, this range is not available on every device.
– Toby N.
18 hours ago
The UNI-T is an order of magnitude cheaper than the Fluke. The specs are probably a lot worse, and quality control will be as well. Hobbyists aren't too picky about that stuff, but if you're a company with millions of dollars on the line, you're willing to pay for quality guarantees.
– Adam Haun
16 hours ago
You're correct. After more research, I realized that Fluke has multimeters specific to the use case. As you said, Fluke 116 with only µA range. It was confusing me, that some multimeters (for example UNI-T) just come with µA almost by default and in the professional area, this range is not available on every device.
– Toby N.
18 hours ago
You're correct. After more research, I realized that Fluke has multimeters specific to the use case. As you said, Fluke 116 with only µA range. It was confusing me, that some multimeters (for example UNI-T) just come with µA almost by default and in the professional area, this range is not available on every device.
– Toby N.
18 hours ago
The UNI-T is an order of magnitude cheaper than the Fluke. The specs are probably a lot worse, and quality control will be as well. Hobbyists aren't too picky about that stuff, but if you're a company with millions of dollars on the line, you're willing to pay for quality guarantees.
– Adam Haun
16 hours ago
The UNI-T is an order of magnitude cheaper than the Fluke. The specs are probably a lot worse, and quality control will be as well. Hobbyists aren't too picky about that stuff, but if you're a company with millions of dollars on the line, you're willing to pay for quality guarantees.
– Adam Haun
16 hours ago
add a comment |Â
up vote
6
down vote
When you are developing low-power devices, every nanoAmpere is worth to be saved. For example, when using a CR2032 coin battery you have around 200mAh of capacity. Once I developed a device powered by one of those batteries and I had to check that the microcontroller went to sleep mode (0.6uA) most of the time. Also need to check that when active, the current consumption was in the range of 10uA. In addition, I had to check that sum of every component in the PCB (in their low power mode) matched the sum of the quiescent current stated by their datasheets.
In summary, if you want to get the most of your power source, and be sure that you are handling your hardware/software you have to measure low-power performance of your components, and usually this rate is given in uA or nA.
answered 22 hours ago
GVelascoh
614
New contributor
GVelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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1
Thanks for this answer, it gives a good example and it is easy to understand. I like it with all the other answers here.
– Toby N.
18 hours ago
add a comment |Â
up vote
6
down vote
When you are developing low-power devices, every nanoAmpere is worth to be saved. For example, when using a CR2032 coin battery you have around 200mAh of capacity. Once I developed a device powered by one of those batteries and I had to check that the microcontroller went to sleep mode (0.6uA) most of the time. Also need to check that when active, the current consumption was in the range of 10uA. In addition, I had to check that sum of every component in the PCB (in their low power mode) matched the sum of the quiescent current stated by their datasheets.
In summary, if you want to get the most of your power source, and be sure that you are handling your hardware/software you have to measure low-power performance of your components, and usually this rate is given in uA or nA.
answered 22 hours ago
GVelascoh
614
New contributor
GVelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
1
Thanks for this answer, it gives a good example and it is easy to understand. I like it with all the other answers here.
– Toby N.
18 hours ago
add a comment |Â
up vote
6
down vote
up vote
6
down vote
When you are developing low-power devices, every nanoAmpere is worth to be saved. For example, when using a CR2032 coin battery you have around 200mAh of capacity. Once I developed a device powered by one of those batteries and I had to check that the microcontroller went to sleep mode (0.6uA) most of the time. Also need to check that when active, the current consumption was in the range of 10uA. In addition, I had to check that sum of every component in the PCB (in their low power mode) matched the sum of the quiescent current stated by their datasheets.
In summary, if you want to get the most of your power source, and be sure that you are handling your hardware/software you have to measure low-power performance of your components, and usually this rate is given in uA or nA.
answered 22 hours ago
GVelascoh
614
New contributor
GVelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
When you are developing low-power devices, every nanoAmpere is worth to be saved. For example, when using a CR2032 coin battery you have around 200mAh of capacity. Once I developed a device powered by one of those batteries and I had to check that the microcontroller went to sleep mode (0.6uA) most of the time. Also need to check that when active, the current consumption was in the range of 10uA. In addition, I had to check that sum of every component in the PCB (in their low power mode) matched the sum of the quiescent current stated by their datasheets.
In summary, if you want to get the most of your power source, and be sure that you are handling your hardware/software you have to measure low-power performance of your components, and usually this rate is given in uA or nA.
answered 22 hours ago
GVelascoh
614
New contributor
GVelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 22 hours ago
GVelascoh
614
New contributor
GVelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 22 hours ago
GVelascoh
614
answered 22 hours ago
GVelascoh
614
614
New contributor
GVelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
GVelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
GVelascoh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
1
Thanks for this answer, it gives a good example and it is easy to understand. I like it with all the other answers here.
– Toby N.
18 hours ago
add a comment |Â
1
Thanks for this answer, it gives a good example and it is easy to understand. I like it with all the other answers here.
– Toby N.
18 hours ago
1
1
Thanks for this answer, it gives a good example and it is easy to understand. I like it with all the other answers here.
– Toby N.
18 hours ago
Thanks for this answer, it gives a good example and it is easy to understand. I like it with all the other answers here.
– Toby N.
18 hours ago
add a comment |Â
up vote
3
down vote
Often when performing characterization and modeling of semiconductor devices, leakage currents (which are critical to creating a useful and accurate model) will fall in the micro-ampere range. Typically these measurements would be performed with a Precision Source-Measure Unit (SMU for short). Such measurements are also commonly used in technology development to evaluate the fundamental performance of a given semiconductor process.
answered yesterday
Shamtam
2,0981022
Good point with SMU. For hobby electronic (even dealing with low current devices) it might be not the right measurement device from a cost perspective. So in your personal opinion: Is a multimeter a good alternative or do you think mA range is sufficient? See also the answer of Adam Haun and Peter Smith - interesting stuff with focus on low current.
– Toby N.
17 hours ago
It depends on the application in question. Other answers highlight some specific examples of where the mA range is just not sufficient (e.g. production testing of low-power battery-driven circuits). If the multimeter has the accuracy and/or precision necessary for the measurement, then sure, it's fine. Perhaps it's even feasible to build a circuit using e.g. an instrumentation amplifier to convert a $mu$A range current to something detectable by a cheaper multimeter reliably. Again, it's very application specific.
– Shamtam
14 hours ago
add a comment |Â
up vote
3
down vote
Often when performing characterization and modeling of semiconductor devices, leakage currents (which are critical to creating a useful and accurate model) will fall in the micro-ampere range. Typically these measurements would be performed with a Precision Source-Measure Unit (SMU for short). Such measurements are also commonly used in technology development to evaluate the fundamental performance of a given semiconductor process.
answered yesterday
Shamtam
2,0981022
Good point with SMU. For hobby electronic (even dealing with low current devices) it might be not the right measurement device from a cost perspective. So in your personal opinion: Is a multimeter a good alternative or do you think mA range is sufficient? See also the answer of Adam Haun and Peter Smith - interesting stuff with focus on low current.
– Toby N.
17 hours ago
It depends on the application in question. Other answers highlight some specific examples of where the mA range is just not sufficient (e.g. production testing of low-power battery-driven circuits). If the multimeter has the accuracy and/or precision necessary for the measurement, then sure, it's fine. Perhaps it's even feasible to build a circuit using e.g. an instrumentation amplifier to convert a $mu$A range current to something detectable by a cheaper multimeter reliably. Again, it's very application specific.
– Shamtam
14 hours ago
add a comment |Â
up vote
3
down vote
up vote
3
down vote
Often when performing characterization and modeling of semiconductor devices, leakage currents (which are critical to creating a useful and accurate model) will fall in the micro-ampere range. Typically these measurements would be performed with a Precision Source-Measure Unit (SMU for short). Such measurements are also commonly used in technology development to evaluate the fundamental performance of a given semiconductor process.
answered yesterday
Shamtam
2,0981022
Often when performing characterization and modeling of semiconductor devices, leakage currents (which are critical to creating a useful and accurate model) will fall in the micro-ampere range. Typically these measurements would be performed with a Precision Source-Measure Unit (SMU for short). Such measurements are also commonly used in technology development to evaluate the fundamental performance of a given semiconductor process.
answered yesterday
Shamtam
2,0981022
answered yesterday
Shamtam
2,0981022
answered yesterday
Shamtam
2,0981022
answered yesterday
Shamtam
2,0981022
2,0981022
Good point with SMU. For hobby electronic (even dealing with low current devices) it might be not the right measurement device from a cost perspective. So in your personal opinion: Is a multimeter a good alternative or do you think mA range is sufficient? See also the answer of Adam Haun and Peter Smith - interesting stuff with focus on low current.
– Toby N.
17 hours ago
It depends on the application in question. Other answers highlight some specific examples of where the mA range is just not sufficient (e.g. production testing of low-power battery-driven circuits). If the multimeter has the accuracy and/or precision necessary for the measurement, then sure, it's fine. Perhaps it's even feasible to build a circuit using e.g. an instrumentation amplifier to convert a $mu$A range current to something detectable by a cheaper multimeter reliably. Again, it's very application specific.
– Shamtam
14 hours ago
add a comment |Â
Good point with SMU. For hobby electronic (even dealing with low current devices) it might be not the right measurement device from a cost perspective. So in your personal opinion: Is a multimeter a good alternative or do you think mA range is sufficient? See also the answer of Adam Haun and Peter Smith - interesting stuff with focus on low current.
– Toby N.
17 hours ago
It depends on the application in question. Other answers highlight some specific examples of where the mA range is just not sufficient (e.g. production testing of low-power battery-driven circuits). If the multimeter has the accuracy and/or precision necessary for the measurement, then sure, it's fine. Perhaps it's even feasible to build a circuit using e.g. an instrumentation amplifier to convert a $mu$A range current to something detectable by a cheaper multimeter reliably. Again, it's very application specific.
– Shamtam
14 hours ago
Good point with SMU. For hobby electronic (even dealing with low current devices) it might be not the right measurement device from a cost perspective. So in your personal opinion: Is a multimeter a good alternative or do you think mA range is sufficient? See also the answer of Adam Haun and Peter Smith - interesting stuff with focus on low current.
– Toby N.
17 hours ago
Good point with SMU. For hobby electronic (even dealing with low current devices) it might be not the right measurement device from a cost perspective. So in your personal opinion: Is a multimeter a good alternative or do you think mA range is sufficient? See also the answer of Adam Haun and Peter Smith - interesting stuff with focus on low current.
– Toby N.
17 hours ago
It depends on the application in question. Other answers highlight some specific examples of where the mA range is just not sufficient (e.g. production testing of low-power battery-driven circuits). If the multimeter has the accuracy and/or precision necessary for the measurement, then sure, it's fine. Perhaps it's even feasible to build a circuit using e.g. an instrumentation amplifier to convert a $mu$A range current to something detectable by a cheaper multimeter reliably. Again, it's very application specific.
– Shamtam
14 hours ago
It depends on the application in question. Other answers highlight some specific examples of where the mA range is just not sufficient (e.g. production testing of low-power battery-driven circuits). If the multimeter has the accuracy and/or precision necessary for the measurement, then sure, it's fine. Perhaps it's even feasible to build a circuit using e.g. an instrumentation amplifier to convert a $mu$A range current to something detectable by a cheaper multimeter reliably. Again, it's very application specific.
– Shamtam
14 hours ago
add a comment |Â
up vote
0
down vote
When operating an electron microscope, it is often desirable to know the beam current to the resolution of a few picoamps. Beam currents are small because the goal of an electron microscope is to focus a narrow (and thus low current) beam of electrons on the sample, in order to have the beam interact with small features.
This is accomplished by connecting an ammeter between an electrically isolated sample stage and the microscope ground. Such an ammeter must, of course, be able to measure in the range of currents used by the instrument.
answered 12 hours ago
Owen
60036
add a comment |Â
up vote
0
down vote
When operating an electron microscope, it is often desirable to know the beam current to the resolution of a few picoamps. Beam currents are small because the goal of an electron microscope is to focus a narrow (and thus low current) beam of electrons on the sample, in order to have the beam interact with small features.
This is accomplished by connecting an ammeter between an electrically isolated sample stage and the microscope ground. Such an ammeter must, of course, be able to measure in the range of currents used by the instrument.
answered 12 hours ago
Owen
60036
add a comment |Â
up vote
0
down vote
up vote
0
down vote
When operating an electron microscope, it is often desirable to know the beam current to the resolution of a few picoamps. Beam currents are small because the goal of an electron microscope is to focus a narrow (and thus low current) beam of electrons on the sample, in order to have the beam interact with small features.
This is accomplished by connecting an ammeter between an electrically isolated sample stage and the microscope ground. Such an ammeter must, of course, be able to measure in the range of currents used by the instrument.
answered 12 hours ago
Owen
60036
When operating an electron microscope, it is often desirable to know the beam current to the resolution of a few picoamps. Beam currents are small because the goal of an electron microscope is to focus a narrow (and thus low current) beam of electrons on the sample, in order to have the beam interact with small features.
This is accomplished by connecting an ammeter between an electrically isolated sample stage and the microscope ground. Such an ammeter must, of course, be able to measure in the range of currents used by the instrument.
answered 12 hours ago
Owen
60036
answered 12 hours ago
Owen
60036
answered 12 hours ago
Owen
60036
answered 12 hours ago
Owen
60036
60036
add a comment |Â
add a comment |Â
Toby N. is a new contributor. Be nice, and check out our Code of Conduct.
Toby N. is a new contributor. Be nice, and check out our Code of Conduct.
Toby N. is a new contributor. Be nice, and check out our Code of Conduct.
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4
Have you ever heard of devices that run for 80000 hours with a 2000mAh battery?
– PlasmaHH
yesterday
3
Not an answer, but it's worth noting that the test equipment company Keithley makes ammeters with a resolution of 10 fA, and Keysight's B2980A series has a resolution of 0.01 fA, which is frankly quite ridiculous.
– Felthry
23 hours ago
3
@Felthry: I had my hands on equipment that would count electrons. And it had to be recalibrated afterwards...
– PlasmaHH
23 hours ago
2
Dave Jones, from the EEVblog, also had this problem and developed the uCurrent.
– Jeroen3
23 hours ago
@PlasmaHH Yes, of course. But for developing and/or repairing, a SMU device would be much more appropriated - see also answer from Shamatam. So do you think it really makes sense to have a multimeter with µA support? In case you work with such devices. Just a question, I'm not saying that such multimeter is useless.
– Toby N.
20 hours ago