SU683460A1 - Thermoelectric device for measuring weak radiation energy fluxes - Google Patents

Description

radiant energy, placed in a common cylinder 11.

The operation of the proposed device is as follows. Before starting measurements, when irradiators are received by detectors 1 and 2 by an additional source 10 of radiant energy, the recording instrument 9 is set to zero using a source 8 of compensating voltage. This eliminates the effect of deviations of the parameters of the elements that make up the symmetrical arms of the device and possible local temperature fluctuations. With both the energy flow W and W present, the temperatures of the receivers 1 and 2 of the radiation will be greater than the ambient temperature That in the balloon. Let the temperature of receiver 1 be Tb and receiver 2 Tr. Considering that the heat removal from the radiation sources I and 2 is proportional to the temperature difference (Ti-TO) and (T2-TO), respectively, we will have:

W / (T, -T,),

W + (T, T,},

where K is the heat transfer coefficient.

Assuming that thermal sensors 3 and 4 are equivalent and have differential thermopower a, for thermopower sensors 3

63 and 4 64 we get:

W (T, - -,

TO

W-i- & W

c, d and (d, - r j a

to

Therefore, the currents will flow through the resistance Rz and Re of thermocouples 5 and 6:

W,

YazfisK

I - -

(G + L). R, 1, K

The powers allocated to thermocouples 5 and 6 will be equal to

. (U1

D) / 2g. “V)

Vb - / 4Av - (t:)

V a

Thus, the temperature of the resistances and Re thermocouples increases TC and become, respectively, T3 and T4, and, obviously,.

It is known that heat removal from the indicated resistances is proportional to (Tz-TQ) and (T4-TO). Taking into account the equivalence of resistance thermocouples 5 and 6 (), we have:

/ her V "72

Q. (-j)

about -( (

Qe - ((/ 4 L),

 Kj

Lb

where Ko is the coefficient of heat transfer resistance. Consequently:

5T, T, -1- (+.

 - And about

From where the thermopower at the output of thermocouples will be:

(2W & W + W).

S,:

Thus, the expression for the output power will be as follows:

: (2WAW + &. WJ.

No.-. „..

,

If there is no energy flow W:

W -

out -

Therefore, the ratio WEMX output can be considered as the gain factor p of the proposed device:

li DblX4W

fW

iW

provided

As can be seen from the last expression, taking a higher power W compared to AW, it is possible to increase the gain factor p unlimitedly.

Thus, the circuit is also used as a power amplifier.

The advantages of the proposed device for measuring weak fluxes of radiant energy are: absence in the circuit

active elements; the mutual destructive effect of the temperature drift of the output signal due to the counter-switching of the thermal converters. The consequence is a reduction in noise figure and an increase in sensitivity.

Claims (2)

Invention Formula A thermoelectric device for measuring weak fluxes of radiant energy, containing two radiation detectors and a circuit of two thermal sensors connected through a signal power supply circuit to a recording device located in a common cylinder, and containing a compensating voltage source in the circuit of the recording device, characterized by the purpose of increasing sensitivity by reducing the coefficient of schum, A source of radiant energy is introduced into the device for additional irradiation of the receivers, and thermal converters with a differential thermocouple connected to them are isolated from each other in the receiver. Sources of information taken into account in the examination 1. "Lustrum and Cont, Syst 1975, 48, No. 6, p. 33-35. 2. Scholl J., Infrared Receivers, M., Mir, 1969, p. 164-167 (prototype).