Calibration of thermocouple hygrometers

Correction of thermal gradient errors in stem thermocouple hygrometers.

Stem thermocouple hygrometers were subjected to transient and stable thermal gradients while in contact with reference solutions of NaCl. Both dew point and psychrometric voltages were directly related to zero offset voltages, the latter reflecting the size of the thermal gradient. Although slopes were affected by absolute temperature, they were not affected by water potential. One hygrometer r...

Uncertainties in the Whole Range of the Calibration of a Thermocouple

− This contribution describes the procedure of evaluating the calibration of thermocouple by means of its comparison with the thermocouple standard. In the process of thermocouple calibration by means of comparison, the resulting uncertainty specified by applying the generalized procedure for evaluating the calibration of measuring devices with continuous scale. The advantage of this method of ...

Thermocouple Measurement

In 1822, Thomas Seebeck, an Estonian physician, accidentally joined semicircular pieces of bismuth and copper (Figure 1) while studying thermal effects on galvanic arrangements. A nearby compass indicated a magnetic disturbance. Seebeck experimented repeatedly with different metal combinations at various temperatures, noting relative magnetic fi eld strengths. Curiously, he did not believe that...

Construction Material Monitoring with «optical Hair» Hygrometers

Evaporative microclimate driven hygrometers and hygromotors

A strip of paper placed on a hand spontaneously curls upwards. This simple observation illustrates the ability of a relatively homogeneous hygroscopic structural material, paper, to sense and respond to the microclimate near a non-equilibrium system, a moist evaporative boundary layer. We quantify this interaction using a simple experiment and show that it can be understood in terms of a minima...