SU1462122A1 - Digital thermometer - Google Patents

Abstract

The invention relates to temperature measurements using quartz thermocouples and improves the accuracy of temperature measurement by reducing the error due to frequency instability of the reference oscillator. The frequency signal from the output of the thermal converter 2, the thermosensitive element of which is placed together with the quartz resonator of the reference frequency generator 3, is fed through the switch 7 and the element OR 8 to the input of the binary-rotary reversible counter 11, where it is converted into a digital temperature code. This code, as well as information about the sign of the temperature, comes from the output of the first trigger 15 to the inputs of the reversible shift register 19 of the memory unit 18. In the permanent reprogrammable memory device 20, the code of the corrections to the frequency instability of the reference generator is received when the temperature is measured by the thermal converter 1 to the information inputs counter 11. 1 Il. (Y (/

Description

I tsish-L "g-

The invention relates to temperature irpHbiM measurements using heat-sensitive stable quartz resonators and can be used in various industrial regions where temperature measurement with increased accuracy is required.

The purpose of the invention is to improve the measurement accuracy by reducing the ... measurement error due to the instability of the frequency of the reference oscillator.

 The drawing shows the structure-: on the digital thermometer circuit, i The digital thermometer contains the first thermal converter 1 with the frequency-: output. For example, a generator with a quartz temperature sensitive piezo resonator, the second thermal transducer 2 with a frequency output identical to the first one, the temperature sensitive element of which is placed together with the quartz piezoresistor of the measurement generator 10 contains a binary 10

15

20

decimal reversible counter 11 and successively connected to it reversible shift register 12, decoder 13 digital binary code in the code of the seven-segment LED alphanumeric indicator 14, installation RO input in O binary-decimal reversing counter 11 is connected to the output of the second element OR 9, and countable The C input is for the output of the first element OR 8. The C input of the synchronization of the reverse shift register 12 is connected to the sixth output of the pulse distributor 5. The input Rg is set to O of the first trigger of the sign 15 is connected to the output second OR circuit 9, D-input information with output P transfer binary coded decimal up-down counter 11, one input of which the control reverser connected to the output of the first trigger plate 15. Simultaneously, the first outlet

the reference frequency 3 torus in the housing; the revolver of the mark 15 is connected to informative high thermal conductivity, for example, in an aluminum case, in which two holes are made under the piezoreson torus 3 mm apart, the holes They are cut out taking into account that the piezoresonators will be installed on the heat conducting paste. The output of the reference frequency generator 3 pod- keys to the input of the time interval generator 4, performed on a programmable counter, the output of which is connected to the C-sync input of the pulse distributor 5, which uses a divider counter at 8. The output of the first thermal converter 1 is connected to the input the first switch 6, the control input of which is connected to the fifth output of the pulse distributor 5, and the output of the second thermal converter 2 to the input of the second switch 7, the control input of which is connected to the second output ra pulse distributor 5, the seventh output of which is connected to the R input of the installation in O of the pulse distributor 5. I

The output of the first key 6 and the output of the second key 7 are connected to the corresponding input of the second trigger of the sign 16, the installation input in O of which is connected to the sixth output of the pulse distributor 5, and the output

30 is connected to the indicator 17 of the sign of the measured temperature, as which can be used, for example, a light emitting diode.

Memory block 18 includes

2J reversible shift register 19, the information inputs of which are connected to the data outputs of the binary-decimal reversing counter 11 of the counter of the measurement result 10, and the C input

40 synchronization of the reverse shift register 19 is connected to the third output of the pulse distributor 5, as well as reprogrammable memory (PROM) 20, for example, 45 reprogrammable read-only memory with electrical recording of information and erasure with ultraviolet radiation, whose address inputs are connected with the outputs of the data of the reverse shift register 19 of the memory device 18, and the outputs with the information inputs (D ;, -VC) of the binary-decimal reverse counter 11 of the result counter

but to the first and second inputs of the first 55 measurement 10.

circuit OR 8, and the second circuit OR 9 inputs are connected respectively to the first and fourth outputs of the pulse distributor 5. The result counter digital thermometer works as follows.

The reference frequency generator 3 with quartz piezoresonator forms

14621222

Tata measurement 10 contains binary

decimal reversible counter 11 and successively connected to it reversible shift register 12, decoder 13 digital binary code in the code of the seven-segment LED alphanumeric indicator 14, installation RO input in O binary-decimal reversing counter 11 is connected to the output of the second element OR 9, and countable The C input is for the output of the first element OR 8. The C input of the synchronization of the reverse shift register 12 is connected to the sixth output of the pulse distributor 5. The input Rg is set to O of the first trigger of the sign 15 is connected to the output second OR circuit 9, D-input information with output P transfer binary coded decimal up-down counter 11, one input of which the control reverser connected to the output of the first trigger plate 15. Simultaneously, the first outlet

trigger sign 15 is connected to

the second input of the second trigger of the sign 16, the input of the installation of Oh which is connected to the sixth output of the pulse distributor 5, and the output

connected to the indicator 17 of the sign of the measured temperature, in which quality a s. LED can be used, for example.

Memory block 18 includes

a reverse shift register 19, the information inputs of which are connected to the data outputs of a binary-decimal reverse counter 11 of the measurement result counter 10, and a C input

synchronization of the reverse shift register 19 is connected to the third output of the pulse distributor 5, as well as reprogrammable memory (PROM) 20, for example, reprogrammable permanent memory with electrical recording of information and erasing it with ultraviolet radiation, address inputs which are connected to data outputs the reverse shift register 19 of the memory device 18, and the outputs with information inputs (D ;, VC) of the binary-decimal reversible counter 11 of the result counter

 measurement 10.

Digital thermometer works as follows.

The reference frequency generator 3 with quartz piezoresonator forms

a sequence of pulses arriving at the input of the time interval generator 4, from the output of which the pulses with a duration equal to the counting interval are fed to the synchronization input C of the pulse distributor 5. The pulse from the first output of the pulse distributor 5 goes through the second circuit OR 9 to the input O of the first trigger

R settings in About binary-decimal reversive counter 11, which is recorded on the information inputs (Pn., - 0ts)

R installation in sign 15 and at the entrance

15 19 of memory block 18, where information is also received on the sign of the measured temperature from the output of the first trigger of sign 15.

The third pulse from the third output

The thermoconverter 2 frequency present on them in the form of a code, with a value known from passport characteristics

In this case, at the information inputs 20 of the pulse distributor 5, (), corresponding to the units, is fed to the synchronization input C of the reverse

shift register 19 memory block

tens and hundreds of degrees, this code is dialed by setting jumpers between the common bus or the power bus and the information inputs () of counter 11. It is equal to the value of the temperature converter 1 at 0 C multiplied by the counting interval.

The inputs (B, BV) of the counter 11, corresponding to the tenth and the hundredth parts of degrees, information comes from the output of the EPROM 20, but it almost does not affect the measurement accuracy, because the frequency of the quartz crystal frequency generator 3 reference frequency temperature changes to tenths and hundredths of a degree remain almost constant.

The second impulse from the second output.

18, in which information is recorded in it in the form of a digital code,

25 located at its information inputs. This information from the outputs of the reverse shift register 19 of the memory block 18 is fed to the inputs of the EPROM 20, which is previously

30 using the programmer, the values of the corrections for the frequency instability of the reference oscillator for each of the operating temperature ranges are entered, and their number is determined based on the measurement accuracy requirements in the operating temperature range, sampling at the address of a specific correction value for this temperature range. Further

35

counter 11 also changes state, and it begins to work on addition.

At the end of the counting period, the digital code corresponding to the temperature at which the quartz piezoresonator of the second thermal converter 2, and therefore the quartz oscillator of the reference frequency generator 3, appears on the outputs (D, -B) of the data of the binary-decimal reversing counter 11. that arrives at the information inputs of the reverse shift register

19 of memory block 18, where information is also received about the sign of the measured temperature from the output of the first trigger of the sign 15.

The third pulse from the third output

18, in which information is recorded in it in the form of a digital code,

located on its information inputs. This information from the outputs of the reverse shift register 19 of the memory block 18 is fed to the inputs of the EPROM 20, which is previously

using the programmer, the values of the corrections for the frequency instability of the reference oscillator for each of the operating temperature ranges are entered, and their number is determined based on the measurement accuracy requirements in the operating temperature range, sampling at the address of a specific correction value for the given temperature range. Further

ka 11.

The fourth pulse from the fourth pulse distributor 5 is received. The 40th amendment in the form of a code is fed to the second input of the second terminal 7. The key information inputs () the counter-7 is opened. During this pulse, the frequency signal from the output of the second thermal converter 2 through the first input of the second key 7 and then 45 of the pulse distributor 5 through the first element OR 8 enters the cut OR 9 is fed to the input R

to the countable C-input binary-decimal-. 11 reversible counter. Binary-decimal counter 11 starts

50

installation in O of the first trigger sign 15 and returns it to its original state, as well as to the input R of the installation in zero of the counter 11, which is written to the information inputs (DK-Df,), present as a code value of the frequency converter 1 with frequency B1 move

work on subtracting recorded in. him code. When the contents of the binary-decimal reversive counter 11 are passed through O, the output signal from its transfer output P is received at

the informational D-input of the first trigger is 55 RI 0 C, known from its nameplate of the sign 15, translates it into counter characteristics, and to the inputs () a positive steady state. The correction value is recorded.

In this case, at the input of the control +1, the frequency instability of the reference

a binary-decimal reversing generator, which is in the form of

ka 11.

  pop info

The fourth impulse from the fourth, you are corrected in the form of a code, is applied to the input inputs () of the pulse distributor 5, the circuit OR 9 is fed to the input R

 correction in the form of a code is applied to the information inputs () of the pulse distributor pulse counter 5 through the circuit OR 9 is fed to the input R

installation in O of the first trigger sign 15 and returns it to its original state, as well as to the input R of the installation in zero of the counter 11, which is written to the information inputs (DK-Df,), present as a code value of the frequency converter 1 with frequency B1 move

RI 0 C, is known from its passport characteristic, and the value of the correction is written to the inputs ()

jKOfla at the outputs of the PROM 20 of the memory block 18.

i The fifth pulse from the fifth output of the pulse distributor 5 is fed to the second input of the first key 6. During this pulse, the frequency signal from the output of the first thermal converter i1 through the first key 6 and the first OR 8 circuit arrive at the counting C input of the binary-decimal reversible counter 11. The binary-decimal counter reversing 11 starts to work on subtracting the code recorded in it. When crawling the contents of binary-15

decimal reversing counter 11 through O pulse from its transfer output P is fed to the information D- input of the trigger of the sign 15 and translates it into

that notion. At the same time, by the pulse from the output of the trigger stroke of the 15 sign, the binary-decimal reversing counter 11 changes the counting direction and to the end

the measurement period works on addition. At the end of the billing period on; The data outputs of the binary-decimal reversing counter 11 receive information about the measured temperature supplied to the information inputs of the reversing shift register 12 of the counter of the measurement result 10.

The sixth pulse from the output of the pulse distributor 5 is fed to the input of the second triggering switch 16 on the O and the synchronization input of the reverse shift register 12 of the measurement result counter 10.

reference frequency torus with a quartz piezoresonator connected to a time interval former, a measurement result counter with a digital indicator, a first sign trigger, a second sign trigger, the input of which is connected to the output of the first sign trigger, an output connected to the sign indicator, and the installation input is connected to the sixth the output distributes the pulse bodies and the synchronization input of the counter of the measurement result, the transfer output and the reverse control input of which are connected respectively to the information input and output of the first three ger sign of r-l and h a- and w u .s and in that, in order to increase the accuracy of measurement, it

i-li i ЛvJAJl - J.., the opposite stable connection; 20 the second thermal converter is introduced

25

thirty

35

At the same time, information on the sign of the measured temperature is displayed on the indicator of the sign 17, and the value of the measured temperature is displayed on the digital indicator 14.

The seventh pulse from the output of the pulse distributor 5 is supplied to the R-vhrd installation in the pulse distributor 5, and returns it to its original state. This completes the measurement cycle.

Claims (1)

Invention Formula Digital thermometer containing a thermocouple with frequency output, connected to the first input of the first key, second key, generated by a frequency output, the temperature sensitive element of which is placed together with a quartz piezoresonator of the reference frequency generator in a monolithic body with high thermal conductivity, the first and second elements OR, and a memory unit whose information inputs are connected, respectively, with the data outputs of the measurement result counter and the output of the first trigger, and the outputs are connected to the information The counting inputs of the measurement result counter, the information recording resolution input of which is connected to the installation input O of the first sign trigger and the output of the second element OR, and the counter input is connected to the output of the first OR element whose inputs are connected respectively to the Q outputs of the first and second keys, while the inputs of the second element OR are connected respectively with the first and fourth outputs of the pulse distributor, the input of which is connected , to the exit of the temporalizer 45 intervals, the second output of the pulse body distribution is connected to the control input of the second key, whose input is connected to the output of the second thermal converter, the third and fifth outputs of the pulse distributor are connected respectively to the memory input of the first key, and the seventh output is connected to the control input of 55 pulse limiter. reference frequency torus with a quartz piezoresonator connected to a time interval former, a measurement result counter with a digital indicator, a first sign trigger, a second sign trigger whose input is connected to the output of the first sign trigger, an output connected to a sign indicator, and the installation input is connected to the sixth output the pulse distributor and the synchronization input of the counter of the measurement result, the transfer output and the reverse control input of which are connected respectively to the information input and the output of the first three gage of the mark, about t-l and h aa-yu and i. with the fact that, in order to increase the measurement accuracy, into it 0 entered the second thermal converter five 0 five with a frequency output, the temperature-sensitive element of which is placed together with a quartz piezoresonator of the reference frequency generator in a monolithic case with high thermal conductivity, the first and second elements OR, and the memory block, whose information inputs are connected to the output of the measurement result counter and the output the first trigger, and the outputs are connected to the information inputs of the metering result counter, the input of which information is recorded is connected to the installation input in the first three ger mark and output of the second OR gate, a counter input connected to the output of the first OR gate, whose inputs are connected respectively to the Q outputs of the first and second keys, the inputs of the second OR gate connected respectively with the first and fourth distributor outputs pulses whose input is connected , to the exit of the temporalizer 45 intervals, the second output of the pulse distributor is connected to the control input of the second key, whose input is connected to the output of the second thermal converter, the third and fifth outputs of the pulse distributor are connected respectively to the synchronization input of the memory unit and the control input of the first key 50 55 pulse limiter.