Dynamic bridge standard for strain gauge bridge amplifier calibration

This article presents a newly at PTB developed dynamic bridge standard for frequency dependent calibration of strain gauge and piezo-resistive bridge amplifiers. The bridge standard operates in a ratiometric mode by picking up the dc bridge supply voltage which is provided by the bridge amplifier under calibration. The sinusoidal or arbitrary calibration signal, the output voltage of the bridge standard, is generated by multiplying digital-to-analogue converters in combination with a resistive voltage divider. Additionally a reference signal is provided for phase calibration. The bridge standard provides the ability of static and dynamic strain gauge bridge amplifier amplitude and phase calibration in the frequency range from up to 10 kHz. The provided frequency range covers a wide range of industrial measurements of dynamic mechanical quantities such as dynamic force, torque, and pressure.