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LMP7721: Working of PH electrode

chandan dais
Prodigy 20 points
Part Number: LMP7721
Other Parts Discussed in Thread: LM35

Can anyone help me understanding the circuit present in this link without LM35

  • 0
    TI__Guru* 93105 points
    Hi Chandan,

    In the LM35 datasheet, Section 1.1 pH Electrode Characteristics, the electrode transfer function includes temperature (degrees Kelvin) in the numerator of the pH equation. Therefore, one needs to know the temperature in order to obtain an accurate measure of the pH. The LM35 product description states, "The LM35 series are precision integrated-circuit temperature devices with an output voltage linearly-proportional to the Centigrade temperature." It provides a convenient and accurate way to obtain the temperature of the solution in which the pH electrode is submerged.

    If the LM35 is excluded from the pH measurement circuit some other means of accurately measuring the temperature must be used.

    Regards, Thomas
    Precision Amplifiers Applications Engineering
  • 0 in reply to Thomas Kuehl
    TI__Guru* 93105 points
    Hi Chandan,

    Does this take care of your pH electrode inquiry? If so, please consider closing the E2E forum inquiry.

    Regards, Thomas
    Precision Amplifiers Applications Engineering