Voltage Measurement Instrument

[hahsan]

Hi,

I'm looking for an instrument such as a voltmeter that can measure voltage drop across two points. I would like it to have an output I can connect to my computer so that I can monitor the voltage on LabVIEW.

Can anyone recommend an instrument for me?

Thanks

[Henrik_Volkers]

Well, I have to get from point A to B, what do I need?  Answers can range from

-jump!

-just walk!

-boat?

-car?

-plane?

-rocket?

distance? needed speed? payload?

Same with your voltage measurement, please give more information, that may increase the number of helpful answers 😉

Range can be from ~40$ to >40 000$  

[hahsan]

I need an instrument that can measure the voltage across two electrodes. The instrument and electrodes will be within a few meters of each other. The range of the instrument will be around +/- 20 V with a resolution of 1 mV. The price should preferably be less than $500.

Let me know if you need any more details.

[johnsold]

How fast do you need to get the readings? Is there anything nearby (such as a speed-controlled motor or temperature-controlled oven) which might generate electrical interference? Does the instrument need a human-readable display or only computer interface? Do you have a preferred communications method to talk to the computer (Ethernet, RS-232, GPIB)? Do you already have any interface equipment to connect such communications methods to the computer?

Lynn

[hahsan]

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@johnsold wrote:

How fast do you need to get the readings? Is there anything nearby (such as a speed-controlled motor or temperature-controlled oven) which might generate electrical interference? Does the instrument need a human-readable display or only computer interface? Do you have a preferred communications method to talk to the computer (Ethernet, RS-232, GPIB)? Do you already have any interface equipment to connect such communications methods to the computer?

Lynn

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I would like the unit to have a response time of less than 10 milliseconds. There is a small pump operating nearby. The instrument only needs a computer interface. I don't have a preferred communications method. The cheapest method is preferred. I do not have any interface equipment to connect to the computer.

[johnsold]

OK. You probably should be looking at a 16-bit DAQ card or module. Most voltmeters, at least the inexpensive ones, have response times much longer than 10 ms at that resolution. 

The USB-6002 and USB-6003 appear to meet the minimum specifications except for a maximum voltage range of +/-10 V.  Not very many DAQ devices have higher ranges than that.  You may need to put voltage dividers or other signal conditioners between your signal and the DAQ device.

Lynn

[hahsan]

What accessories do I need to get in order to allow for voltage dividers or signal conditioning so that I can measure +/- 20 V?

[Dennis_Knutson]

You just need resistors for a voltage divider. Place them on a proto board. This is electronics 101.

[Dennis_Knutson]

And consider the myDAQ with its built-in dmm.

http://www.studica.com/mydaq