SU91602A1 - Power meter - Google Patents

Description

The prior art power measurement devices have insufficient sensitivity, considerable thermal inertia, and their readings depend on the ambient temperature.

In the proposed device, these disadvantages are eliminated by the fact that bolometers, which due to their high sensitivity to the radiant energy they absorb, are widely used in the technique of measuring ultrashort waves, are used as working elements with a quadratic characteristic. Bolometers are usually used to measure the radiant energy absorbed by the bolometer itself. In the proposed device, bolometers are used to measure the power consumed by various electrical objects from the external network.

FIG. 1 shows a diagram of the proposed device; in fig. 2 and 3 are the installation diagrams of the device elements in the general casing.

The device is made in the form of two bridges: an unbalanced bolometric bridge V and a measuring bridge 2. The diagonal AB of the bolometric bridge / is included in the DC or AC circuit, and the diagonal of the SD is connected to the corresponding sensitive device 3 for current measurement. The two adjacent shoulders of the bridge, CA and HELL, are made in the form of coils 4 and 5 of thin tungsten wire, which vary their resistance to temperature (bolometric shoulders). Spirals 4 and 5 are heated by two filament wires B and 7, which are included in the AC measuring bridge circuit 2, so that a sum passes through one of the filament wires and the difference between the instantaneous values of two alternating currents of one frequency proportional to the current and the voltage of the controlled circuit. The quadratic nature of the dependence of the bolometric elements can be ensured by choosing the proper diameters of the filament wire and the bolometric spiral, the auxiliary current density in the bolometric spiral and the current density of the heat corresponding to the heat exchange in the bolometric element through the thermal conductivity of air.

; N 91G02, .- 2 He3aBHC i i dttb indications of the bolometric instrument as a function of the medium temperature is obtained by placing both bolometric elements of the device in one. 8, divided by screen 9, and the choice of a moderate temperature overheating of the bolometric coil, at which the temperature, wire coefficient is constant. Under these conditions, the difference between the increments of the resistances of both bolometric spirals will not depend on the temperature of the medium. To ensure that the installation time of the galvanometer does not exceed the installation time allowed for indicating devices, the thermal inertia of the bolometric element must be small. This is ensured by reducing the diameters of the bolometric spiral and the filament wire and the introduction of air insulation between them.

Subject invention

Claims (2)

1. A device for measuring the power of an unbalanced bridge with working elements having a quadratic characteristic and one included in the sum, and the other on the difference of currents proportional to the current and voltage in the network, which is only elements with quadratic characteristic applied bolometers. 2. The device according to claim 1, characterized in that, in order to ensure that the characteristics of the bolometers are independent of the ambient temperature and low thermal inertia, both bolometric elements are placed in a common chamber and have air insulation between the filament wire and the bolometric coil. 8 9 fy 6 G D / I I FIG. 2 Fig 1 Fi & 3