Hello, I plan to use a thermocouple to measure temperature and send it to a PLC, I would like to know if it will be enough to use the ad8221ARM (G = 100) and OPA27GP (G = 50). I plan to get Gain = 5000. I will have a 1 / 4HP motor relatively close to the circuit. Please can someone help me with the filtering stage, or what should be the RFI frequency, or the frequency and the low pass filter I should use.
Thank you.

(if there is another op amp, feel free to write me)

  • 0
    •  Analog Employees 
    on Oct 14, 2020 3:09 PM 1 month ago

    Hi abedgarr,

    I think we'll be needing more information on your side in order to give a more effective suggestions or feedback.
    May we ask what's your input level? I'm interested to know why you need a gain of 5000 on your application.
    Have you checked out the AD8496? It's a precision thermocouple amplifier with cold junction compensation, but as I've mentioned we'll need more details of your desired spec in order to suggest the best solution for your application. Also for the 1/4HP motor, do you have a specific picture of your setup?

    Thank you and keep safe.

    Best Regards,