Quick Enquiry

    Thanks for your enquiry. We'll be in touch soon.
    Get our latest product and application news sent directly to your inbox.
    Your email address:*
    Please enter all required fields Click to hide
    Correct invalid entries Click to hide

    What is the Thermal Effect on Zero?

    Thermal zero shift represents the change in null resulting from a change in temperature. Null shift is not a predictable error because it can move up and down from unit to unit.

    Changes in temperature will cause the entire output curve to move up or down along the output axis.

    Graph showing the effect of temperature on the zero of a sensor

    The zero shifts due to temperature could be caused by the difference in the thermal coefficient of expansion of the sensor parts.

    To minimise the zero error with temperature, the differential expansion of the mechanical components must nearly balance out. And to achieve this the sensor must be temperature compensated over a stated range.

    One of the methods used for temperature compensation involves the addition of a temperature-sensitive resistor on one arm of the bridge. The value of the resistor is determined from a temperature test run in which the change in zero reading for the given temperature is found.

    Watch out

    Different manufacturers specify thermal zero shift in different ways: as error per degree Celsius, such as ±0.01%FS/°C; as a total temperature effect, in the form of ±1% of FS; or as an error band, such as ±1% over a 50°C temperature range. There are many more; some with reference to full scale, others to reading. But in each case the specified error is only valid over the compensated temperature range.

    Note that the temperature effect is only valid when the complete sensor housing is heated up. This is because some sensors have their temperature compensation at the rear of the housing.

    A few manufacturers include both zero and span as a total value.

    To understand all temperature effects please refer to the other engineering notes in this series.

    Read more: Index to all of our Technical Notes on Pressure

    Have a pressure application you want to discuss? Let us call you…

      Our call back service is only available for UK phone numbers. If you are based outside the UK, please send us an enquiry using the form on the contact us page.

      Why Us?

      • Suppliers of top quality strain gauge sensors and transducers to every corner of industry – UK and worldwide
      • Over 100 years of expert transducer knowledge
      • Our high quality products all come with a 3 year warranty
      BSI Assurance Mark ISO 9001:2015 FS677584
      We Are a Living Wage Employer
      Cyber Essentials Certified