EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: stagnant7 on November 01, 2018, 06:03:16 am
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Hi Everyone
I'm after a simple voltage and current data logger. It needs to be capable of:
- Monitoring a single phase 110V supply and max 100A current for 24 hrs
- I'd like accuracy of 0.1A is possible (the majority of current readings would be around the 2 - 10A range).
- Record interval requirements are not demanding every few seconds (maximum) would be sufficient
- Accuracy for the voltage readings could be +/- 1V.
- No fancy data analysis software is necessary, just a file that could be imported into excel would be fine.
- Simple to operate and reasonably robust (no electronics kit boards etc)
- Budget is around $300 as I'm after several units.
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I'd appreciate any suggestions of suitable products to research further
Many Thanks
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Well,
for 300 bucks - I see no solution.
Your current measurement accuracy is is 0.1% at 100A - thats a precision shunt for a few 100€.
I have a Rigol M300 data logger (a M302 package with 6 1/2 digit multimeter plus a 20 line input card).
It works fine and accurate, accumulates 100000 measurements, logs to USB in CSV format, is computer controllable, ... but not for 300$.
I used it for long-term stability measurements of voltage references, like here:
https://electronicprojectsforfun.wordpress.com/silly-circuits/silly-circuits-a-heated-lm723-reference/lm723-long-term-stability-results/
Maybe it makes sense to use *one* of those for all your measurements instead of employing several units.
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Depending on how you want to go about this, there are a number of options for you.
PCE Instruments make a relatively basic single phase power monitor, its resolution would be good enough for what you have stated but you will then need to look at if its tolerance meet your specifications. For a 100A range, you would need to utilise a current transducer that will further reduce the accuracy and add to the costs. It would however be a nice 'out of the box solution'.
https://www.pce-instruments.com/english/measuring-instruments/test-meters/1-phase-power-meter-pce-instruments-phase-power-meter-pce-pa6000-1-det_2208272.htm?_list=kat&_listpos=2 (https://www.pce-instruments.com/english/measuring-instruments/test-meters/1-phase-power-meter-pce-instruments-phase-power-meter-pce-pa6000-1-det_2208272.htm?_list=kat&_listpos=2)
There are also a number of logging clamp meters; you may be able to get a Fluke Connect setup within your price range. Extech make the DL160 monitoring kit that is available from Farnell and may be available directly in your country, resolution is similar to what you require, but you would need to look at the accuracy specifications to see if they suit.
https://cpc.farnell.com/extech-instruments/dl160/datalogger-ac-voltage-current/dp/IN06448?mckv=sAxMKYMGd_dc%7Cpcrid%7C224651886477%7Ckword%7C%7Cmatch%7C%7Cplid%7C%7Cslid%7C%7Cproduct%7CIN06448%7Cpgrid%7C47836903635%7Cptaid%7Cpla-370072459389%7C&CMP=KNC-GUK-CPC-SHOPPING&gclid=CjwKCAjwsfreBRB9EiwAikSUHU8vgF3JHCxonNHFvFtGvEofPVVHdupcmT9Ig0_3sFUmC8639X89QxoCR4kQAvD_BwE (https://cpc.farnell.com/extech-instruments/dl160/datalogger-ac-voltage-current/dp/IN06448?mckv=sAxMKYMGd_dc%7Cpcrid%7C224651886477%7Ckword%7C%7Cmatch%7C%7Cplid%7C%7Cslid%7C%7Cproduct%7CIN06448%7Cpgrid%7C47836903635%7Cptaid%7Cpla-370072459389%7C&CMP=KNC-GUK-CPC-SHOPPING&gclid=CjwKCAjwsfreBRB9EiwAikSUHU8vgF3JHCxonNHFvFtGvEofPVVHdupcmT9Ig0_3sFUmC8639X89QxoCR4kQAvD_BwE)
If you want better accuracy and are prepared to do some software work yourself, then you could look at voltage / current transducers with modbus output capability. You would need to parse the data string yourself, but there is plenty of software out there to do this and then store in an access database or a spreadsheet.
PCE Instruments can provide the P41 transducer with a basic accuracy of 0.2%.
https://www.pce-instruments.com/english/measuring-instruments/test-meters/1-phase-power-meter-pce-instruments-single-phase-1-phase-power-converter-pce-p41-det_5844987.htm?_list=kat&_listpos=9 (https://www.pce-instruments.com/english/measuring-instruments/test-meters/1-phase-power-meter-pce-instruments-single-phase-1-phase-power-converter-pce-p41-det_5844987.htm?_list=kat&_listpos=9)
Omni Instruments provide their QA Power Module that has similar functionality to the P41
http://www.omniinstruments.co.uk/data-logger-multi-channel-programmable/single-and-dual-channel-data-loggers/qa-power-m.html (http://www.omniinstruments.co.uk/data-logger-multi-channel-programmable/single-and-dual-channel-data-loggers/qa-power-m.html)
Both of these, you would need to source current transformers for.
For a slightly higher price, but has software options, you could look at the Hobbo range of monitors;
https://www.measurementsystems.co.uk/data-logging/energy_logging/h22-001_energy_logger_data_logger (https://www.measurementsystems.co.uk/data-logging/energy_logging/h22-001_energy_logger_data_logger)
Plenty of options out there if you search for 'single phase energy monitors', 'energy data logger' etc, just depends on what you can compromise on, more budget will give you a solution closer to your technical requirements, but if you can relax your technical needs, you may well get something for your budget.
Unless any of the above are available directly in your country, you will also have shipping and import tax costs to consider.
Kind regards.
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Thank you all for your responses, which made me realise the accuracy I stated was over the top.
In reality I expect most power circuits measured would be <10A at 110V. In terms of accuracy, if a particular monitored power circuit was around the 1.5 to 2A magnitude, I hope to get readings accurate to 0.1A (at least for currents below 10A). Therefore I believe the below logging clamp meter would suffice:
http://www.test-measurement-australia.com.au/node/5872 (http://www.test-measurement-australia.com.au/node/5872)
Could someone please help check if I am interpreting the attached datasheet correctly?
- Resolution varies from 0.1A to 1A over the measurement range 0.5A to 2000A (not sure if I've understood this...)
- The accuracy on the 600A setting is +/- 1%
Therefore if a circuit has a actual current of 1.5A, I should expect the meter would measure a value anywhere between 1.485A to 1.515A, but since the resolution is 0.1A it would simply display 1.5A?
If a circuit has a actual current of 15A, I should expect the meter would measure a value anywhere between 14.85A to 15.15A, but since the resolution is 0.1A it would display a value anywhere between 14.9A to 15.2A?
I'm guessing that at higher readings I'd expect to only get a resolution of 1A as stated on the datasheet - above 100A maybe?
If I have interpreted this correctly then a product like this would be ideal.
Many thanks again.
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The mooshimeter may meet your needs: https://moosh.im/mooshimeter/
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@ billfernandez, interesting little meter you have found there, may well be worth a look some.
Kind regards
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Could someone please help check if I am interpreting the attached datasheet correctly?
- Resolution varies from 0.1A to 1A over the measurement range 0.5A to 2000A (not sure if I've understood this...)
- The accuracy on the 600A setting is +/- 1%
Yes, it looks like the current has a resolution of 0.1A, probably up to 999.9A, and then 1000A above will be a 1A resolution.
The accuracy on the 600A range is +/-1% +12 digits, on the 2000A range it is +/-1% +8 digits.
Therefore if a circuit has a actual current of 1.5A, I should expect the meter would measure a value anywhere between 1.485A to 1.515A, but since the resolution is 0.1A it would simply display 1.5A?
If a circuit has a actual current of 15A, I should expect the meter would measure a value anywhere between 14.85A to 15.15A, but since the resolution is 0.1A it would display a value anywhere between 14.9A to 15.2A?
For an actual current of 1.5A, the meter would display anywhere between 0.5A and 2.7A, at 15A the reading would be between 13.7A and 16.3A.
The downside to using current clamps, is that the accuracy is affected by the placement of the conductor within the jaws, this is excaserbated by the low current being measured using a high relatively high 600A range. In practice, with careful use, you are likely to achieve better accuracy than stated, but the manufacturer is likely to specify worst case scenario.
The meter does have some interesting functionality, but if you want better accuracy at the lower amps, you would probably be better off looking for a meter with a lower range than 600A.
Kind regards
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Thank you all for your helpful replies, it helped me a lot in my understanding.
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I have a few Lascar loggers.
The models I have look like oversize USB key, battery operated for months, and can monitor and log from seconds to days for temp, voltage, current and many other parameters, including one with two test clips that you can customize to your needs.
You then read the data via a USB in the format you like.
Best bang for the buck for my automotive monitoring application and easy of use.
You might have to explore the website a bit as they have quite a range.
https://www.lascarelectronics.com/ (https://www.lascarelectronics.com/)
https://www.lascarelectronics.com/data-loggers/voltage-current/ (https://www.lascarelectronics.com/data-loggers/voltage-current/)