SU819672A1 - Plane-parallel primary transducer of soil moisture content - Google Patents

Description

(54) PLAT-PARALLEL PRIMARY CONVERTER

MOISTURE SOIL.

transducer transducer moisture meter and reducing the depth of effort.

The goal is achieved by the fact that in a known primary transducer-probe of a moisture meter containing two electrodes in the form of pointed blades connected to a dielectric base, a rod with a handle, one electrode is fixed on the dielectric base stationary, and the other is movable and fixed in positions, while in one of them the movable electrode is located inside the dielectric base, and the front part of the dielectric base in the plane of the electrodes is It is cut according to the shape of their cutting edges and, in a perpendicular plane, is cut at an angle of 30-45 ° С, which ensures the material to slide off during the penetration.

FIG. 1 and 2 shows the converter, a general view; in fig. 3 and 4 - the same, longitudinal and transverse sections.

The primary transducer probe consists of a stationary knife electrode 1 mounted on a dielectric base 2 and a movable knife electrode 3 connected to the handle 4 by means of a connecting rod 5. The positions of the moving electrode are determined by focusing the pad 6 on the upper and lower edges of the dielectric the bases and are fixed by spring-loaded balls 7. The same balls are used for contact in the upper position of the pad (measurement mode) from the fixed electrode to the plate 8 to which the wire 9 is attached. Dielectric The base plate is fixed on the connecting rod 10 with a scale of immersion of the converter into the material. The potential is a fixed electrode as well. earthly - mobile. Using a shielded cable, the transducer is connected to the measuring circuit of the moisture meter, which converts changes in its electrical capacitance, caused by changes in the humidity of the monitored material, into a recorded electrical signal.

The process of measuring humidity occurs in the following sequence. With a recessed moving electrode, the primary transducer goes deeper into the material to a predetermined depth. With handle 4

The movable knife-electrode 3 is extended to the stop of the pad 6 at the upper edge of the dielectric base groove 2. After that, the device is turned on and the readings are read. If necessary

measuring the humidity at another depth, the movable electrode 3 is pushed inside the dielectric base 2 until it stops, the transmitter is further buried to the desired depth. After this, the movable electrode 3 is advanced again and the humidity is measured. An increase in the measurement accuracy is achieved due to the fact that the material in the measuring space of the transducer retains an almost unbroken primary structure, since during immersion before measurement, not simultaneous, but alternate cutting of the material with thin knives-electrodes occurs. Due to this, a reduction in the force is achieved at the depth. When the transducer is immersed to a different depth, the material between the electrodes during the first measurement has the opportunity to move aside due to the shearing of the dielectric base (the movable electrode is recessed).

Claims (2)

1. USSR author's certificate No. 265499, cl. G 01 N 27/22, 1968. 2. Leska GI and Flamin EE. Electric moisture meters. - Factory Laboratory, 1958, No. 9, Vol. XXIV (prototype).