Ambient pressure compensation for hermetically sealed force transducers

• Ambient pressure fluctuations affect readings of sealed force transducers.
• The influence can be effectively compensated for by referring to zero sensitivity.
• Pressure compensation improves repeatability and hence measurement uncertainty.
• Pressure compensation is useful for precise estimation of creep and hysteresis.

Readings of hermetically sealed force transducers are affected by fluctuations in atmospheric pressure, and measured deflections vary when the ambient pressure changes quickly between two readings at zero force and at a certain force step. For some types of force transducers, readings at the zero point are quite sensitive to the ambient pressure change and this influence is not negligible. By periodically repeating measurements on two force transducers, it was verified that the repeatability of the measurements can be improved, and hence calibration uncertainty can be reduced to some extent, by compensating for deflections of the force transducers due to ambient pressure fluctuations by referring to the zero sensitivity.