Abstract

KHALED, K.M.  and  MAHMOUD, G.M.. An investigation on the effect of humidity on the zero signal of a strain gauge measuring system. Univ. Sci. [online]. 2018, vol.23, n.1, pp.129-139. ISSN 0122-7483.  https://doi.org/10.11144/javeriana.sc23-1.aint.

Humidity is one of the most important ambient factors influencing torque calibration readings. The present study addresses the effects of relative humidity on the readings of reference torque transduction and amplification devices. The results revealed a linear effect of increasing humidity on the readings of a DMP40 torque amplifier and a torque transducer at different temperatures. Furthermore, humidity effects were smaller on the DMP40 amplifier than on the torque transducer, even at different temperatures. The results also showed that the summed effect of humidity changes on torque calibration readings of the amplifier and the torque transducer, when assessed simultaneously, but with each device under different controlled humidity conditions, is greater than the observed effect on the readings when both devices were subjected to humidity changes together. Therefore, it is recommended to test the effect of humidity in setups where these two devices are both under common humidity conditions. This is likely to lower the uncertainty parameter of the obtained torque calibration readings and is a useful consideration for inter-laboratory comparisons and performance testing.

Keywords : Strain gage; torque amplifier; relative humidity; ambient temperature; international system.

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