DEVICE FOR MEASURING MOISTURE OF GRANULAR MATERIALS Russian patent published in 2011 - IPC G01N27/22 

FIELD: physics.

SUBSTANCE: device for measuring moisture of granular materials has electrically connected self-excited quartz-crystal generator of high frequency pulsed oscillations on a transistor, measuring circuit having transistor preamplifier 1, amplifier 2, sensor with capacitor electrodes, diodes 3, 4, measuring device 5, power supply 6. The capacitor electrodes are in form of inductance coils 13, 14. The device also has inductive electrodes connected in the measuring circuit. The sign of the temperature coefficient of inductance of the additional electrodes coincides with that of the temperature coefficient of permittivity of the test material. The inductive electrodes are in form of weakly inductive coupled inductance coils 9, 10 which are insulated from the external medium by a coating. The coupling element between the inductance coils is the test material and the axes of the electrodes on which the coils lie are parallel. All inductance coils 9, 10, 13 and 14 are wound on insulated bases using a double-wound technique in one layer, where two windings of each inductance coil 9, 13 are connected in series and two windings of each inductance coil 10, 14 are connected in parallel.

EFFECT: high accuracy of measuring moisture of granular materials at different temperature.

2 dwg