Signal conditioner (amplifier) for cDAQ system!

[Padeanu.L]

The system that I want to build will be used to monitor the excitation system of an generator/motor. I have a couple of signal that are bellow 100 mV, for example excitation current measured with a shunt resistor  40 A/ 60 mV.The problem is that I what to amplify the signal to get more accuracy. Can someone supply me with a hardware conditioning option (low cost). I have at my disposal two NI 9201 and one NI 9205 card. 

Thank you have a nice day!

[REDS · Accepted solution]

Hello Padeanu,

Thanks for posting on the Discussion Forums! The 9205 already has a PGIA (Programmable Gain Instrument Amplifier) that amplifies your signal so you won't lose accuracy. According to the specifications, you will get 174 uV of accuracy using the 200 mV voltage range and a code width of 6.57 uV / LSB. Is your current setup too inaccurate for you? Will the excitation system for your motor be always below 100 mV, even when the motor is on?

[Padeanu.L]

Yes the excitation curent will be between 0 - 75 mV or 0-150 mV depending on the shunt resistor uset for measurement. Thank you for the heads up I will test your answer and come back with the results!