Measuring differential voltages for voltage range 0-20 V

[sbrawn]

I'm trying to figure out the best way to measure the internal voltages across an electrolyzer stack containing 10 cells.  Voltage range will be 0-20V, with each differential voltage measuring 0-2V.   I know that each module on a NI-DAQ (6218, 6210, 6009, etc) can not see voltages greater than 10V.    If I use the AISense or ground the second board to the high voltage from the first 5 cells (~10V), will I damage the board or will that enable me to reach the 20V upper limit of the system.  Additionally, I need to be able to measure the voltages simultaneously. 

If there is a better piece of hardware or board for this topic, please let me know.  I'm posting on the multi-function DAQ board because that's the hardware that I'm familiar(-ish) with and it's what we have in house right now.

[sbrawn]

I should note that I do know that I can use voltage dividers and condition the signals that way, I was just wondering if there is a way to do this without the voltage divider.   Thanks. 

[Tunde_S · Accepted solution]

Hi sbrawn,

I recommend reading the High-Voltage Measurements and Isolation DevZone.

If you are looking for a DAQ device that has a voltage range greater than 10 V, I recommend searching the product catalog here.

[Henrik_Volkers]

How about 5 INA2128  ?

This is an instrumentation amplifier already including 8 laser trimmed resistors and a input protection circuit and work up to 36V

Depending on the input range of your DAQ you could add gain (however might not be needed)

Use the DIP version in a socket, so if you blow one up is a quick replacement 😉