SU1464049A1 - Method and apparatus for determining temperature - Google Patents

Abstract

The invention relates to the field of temperature measurements and allows to increase the accuracy and reliability of oqpe-dividing the temperature of the studied media with the use of two resistive thermal converters due to that. That the measurement result does not depend on the instability in time of the parameters of thermal converters and the parameters of the measuring circuit. The proposed method involves the use of two resistive thermocouples with different output characteristics, and consists in registering the output signals of thermocouples at two different temperatures, the measured and the additional one, and then calculating the value of the measured temperature by the calculated formula. Various options are proposed for obtaining additional temperatures — artificially heating thermal converters or moving them from one point of the medium to another. A device that implements the proposed method contains a measuring probe 1 with two thermal converters 2 and 3, heaters 4 and 5, operational amplifiers 6 and 7, resistors 8 and 9, the voltage source 10, the power supply 11 of the heaters, switch 12, analog digital converter 13, microprocessor module 14, which includes a software-controlled timer 15 and a central processor 16. 2 sec. and 3 hp ff, 1 ill. (from about

Description

-

Uc

Roa

(

r

at,)

40

0 od-NavCNn -N, t) -ofi-Niv (N7, -Nn) 1 T, (Nl.)

where and is the reference voltage of source 10; 45 g is the resistance of resistors 8 and 9;

61

RO, - resistances of thermal converters 2 and 3, respectively, at temperature Q

at 0 ° C;

c / t o (i, - temperature coefficients (c, yfo (j) of the resistance of thermal converters 2 and 3, respectively. Using the control signal of timer 15, switch 12 alternately connects the outputs of operational amplifiers 6 and 7, output i

The values of the temperature coefficients of resistances, n, and thermocouples 2 and 3 are recorded in the memory of the central processor 16 in advance.

If necessary: in the central processor 16, a temperature value of 6-2 can also be calculated. according to the formula

in (Nj,., (Nji, -Ni-0 of, c, (Nj, N -N ,,. N,)

As follows from the above expressions for determining temperatures.

20

25

the latter do not depend on the parameters of resistance thermometers (Ret) that are unstable in time as well as on the parameters of the electronic circuit of the device U ,,, r and K.

In geothermal studies related to temperature measurements of the bottom sediments of the seas and oceans, the proposed method can be pea-IQ leased without artificial heating of the thermal converters of resistance, i.e. without the use of heating elements. In this case, both resistive temperature transducers are placed in series at two points of the bottom sediments with different horizontal coordinates, i.e. points that have obviously different temperatures, or are transferred from a controlled point of bottom sediments to water.

Claims (5)

Formula invented , 1. The method of determining the temperature, which consists in placing two resistive thermal converters with different temperature coefficients of resistance and recording their output signals in the medium under study, is designed so as to change the temperature in order to increase accuracy and reliability. resistive thermocouples, additionally register their output signals and determine the temperature of the medium using the obtained four values of the output signals of the thermocouplers. 2. The method according to claim 1, characterized in that with repeated long-term temperature measurements At the same point of the test medium, additional registration of 5 output signals of thermocouples is carried out with their artificial heating. 3. Method pop. 1, distinguished by the fact that with geothermal g 35 40 146A049 0 five Q 5 about five five 0 studies related to measurements of the temperature of bottom sea sediments. and oceans, both thermocouples after the first registration of their output signals are moved from one point of the test medium to another. 4. A method according to claims 1 and 3, which is often due to the fact that additional recording of the output signals of the thermocouples is performed after their placement in water. 5. A device for determining the temperature, containing a measuring probe with two resistive thermocouples, two operational amplifiers, the negative feedback circuits of which include resistive thermal converters, a reference voltage source, an analog-to-digital converter and two resistors, the first terminals of which connected to the inputs of the operational amplifiers, and the second outputs are combined and connected to the output of the reference voltage source, which is different, which, in order to improve the accuracy and reliability, put into it Two wire heaters, wound on thermal converters, heater power supply, switch and microprocessor module, include a central processor and a program; a multi-controlled timer; the heater i.o6a are connected in parallel and connected to the output of the heater power supply, operating outputs amplifiers are connected to the inputs of a switch, the output of which is connected to the input of an analog-digital converter, the output of which is connected to the first input of the central processor, the second input of which It is connected to the first output of the timer, and its output is connected to the control input of the timer, the second and third outputs of which are connected to the control inputs, respectively, of the power supply of the heaters and switch.