DEVELOPMENT AND METROLOGICAL INVESTIGATIONS OF THE CHARACTERISTICS OF A PRIMARY TRANSDUCER OF MOISTURE OF MATERIALS

The author has proposed a structure of the facility for measuring the moisture of materials, that contains the case, the cover, capacitive electrodes, the measuring resonant circuit, inductance coils, capacitors, the alternating-volt- age source, and the indicator device. Metrological properties have been investigated from the results of the con- ducted experiment within the measurement scale. Here, two capacitive electrodes located at the base of the cylin- drical case were manufactured from copper foil in the form of a "double circle" and were connected, via the switch, in parallel with the reference capacitor and with one adjacent capacitor of the ferroresonant bridge circuit, and the other two adjacent inductance arms of the ferroresonant bridge circuit were manufactured in the form of two aiding-connected coils wound onto the shared core in the form of a toroid. Here, the ferroresonant bridge circuit at the output is connected to the threshold voltage indicator, and at the input, to an a.c. circuit with a frequency of 50 Hz via the autotransformer the handler of whose arm is jointed to the pointer of an arc scale in units of humidity of food and other loose materials.

Author:  Sh. M. Masharipov
Keywords:  moisture of a material, capacitive method, electrode, measuring resonant circuit, inductance coil, alternating-voltage source, indicator device, ferroresonant bridge circuit