Thermocouple circuit

Discussion in 'The Projects Forum' started by Konstabel, Feb 22, 2008.

  1. Konstabel

    Thread Starter Active Member

    Jan 31, 2008
    52
    0
    In the attached circuit from the LT1025 datasheet, it is noted "Selected for 0-100 degree range". How was this resistor value chosen? I am looking to apply this circuit to a 0-150 degree range.
     
  2. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    The answer lies in the fact that the temperature coefficient of the type-K thermocouple is 40.3 microvolts per degree C. To get to 10 millivolts per degree C requires a gain of around 244. The opamp's gain is therefore set to this value by the selection of the feedback resistors.

    hgmjr
     
Loading...