SU1084624A1 - Digital temperature meter - Google Patents

Abstract

DIGITAL TEMPERATURE METER containing a voltage-code thermal converter, memory block, display unit including a decoder and an indicator connected in series to an adder and a register whose output is connected to an input of an adder, a control unit connected to a voltage converter — a code with a lmator, a recorder and a memory unit, characterized in that, in order to improve measurement accuracy while reducing the requirements for a voltage converter, a code, an integrator, a coupling capacitor and a analog are entered into it A second adder, the first input of which is connected to the output of the transducer1 of the converter, the second input is connected via a separating capacitor to the output of the integrator connected to the control unit, and the output is connected to the input of the voltage converter - the code that output- adder input, while the input of the memory unit is connected to the output from the register, and the output is connected to the display unit.

Description

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The invention relates to temporal measurements, namely digital temperature meters, and can be used, for example, as a medical thermometer for use in inpatient clinics, clinics and in everyday life.

Electronic medical digital thermometers are known that contain a series-connected thermoconducer; a generator, a voltage transducer code, a memory unit, an optoelectronic indicator, and a control circuit. Characteristic For these medical thermometers is the use of a voltage converter — a code in the form of an integrated circuit with a high degree of integration (LSI), which includes a memory unit and a decoder for controlling the digital indicator ij and 2.

The lack of thermometers - low noise immunity due to the fact that the results of measuring the temperature values during a short measurement time are subject to fluctuations due to interference in the external thermal sensors and the drift of the thermal converter.

The closest in technical essence to the present invention is a digital temperature meter comprising a thermoconverter, a voltage-code converter, a memory unit, a display unit including a decoder and an indicator connected in series to the adder and a register whose output is connected to the first input of the adder a control unit connected to the converter, a voltage-code, an adder, a recorder and a memory unit z1.

A disadvantage of the known thermometer is the need to use a sufficiently accurate voltage-code converter to provide the required resolution and accuracy in the temperature range of 34.0-42.0 ° C specified for a medical thermometer, which leads to an increase in the size of the thermometer and an increase in its cost.

Indeed, for voltage-to-code converters, made in the form of an integrated circuit, it is characteristic that the maximum value of its scale in decimal representation on the indicator is equal to

 2

. bi:

where n is the number of binary bits of the voltage-to-voltage converter.

In order to select on the npeo6pa ct scale the temperature plotter from 34 to 42s with a resolution of 0.1 C, n must be equal to 10. Then the maximum value of the scale will be 1023 units. Using part

the range of the converter from the values of the scale 340 to 420 and three lower digits of the indicator, it is possible to provide temperature measurement with a resolution of 0.1 ° C.

However, the presence of instrumental error of the voltage-code converter, which is usually equal to a few low-order bits, leads to an unacceptable measurement error, which is set to

ion ° c.

To eliminate this error, a converter with a higher Bitrate is used, for example, 11-12 bits of the maximum scale value

in 2043 or 4095 units. In this case, the value of the highest decimal digit of the indicator is shifted by recoding by 3 or 1 units, respectively, and in the thermometer four or three major bits of the indicator are indicated.

The purpose of the invention is to improve the measurement accuracy while reducing the voltage requirements of the voltage transducer and reducing the size of the device.

The goal is achieved by the fact that a digital temperature meter containing a thermal converter, a voltage-code converter, a memory unit, a display unit including a decoder and an indicator are connected in series to an adder and a register whose output is connected to the first input of an adder, a control unit connected to a voltage-code converter, an adder, a recorder, and a memory unit; an integrator, a coupling capacitor, and an analog adder, the first input of which is connected to the output of the thermal the second input is via a pci3 separator, the capacitor is connected to the integrator output connected to the control unit, and the output is connected to the voltage converter; the output of which is connected to the second input of the adder, the input of the memory block is connected to the register output, and output is connected to the display unit.

The drawing shows a block diagram of a digital temperature meter.

The device contains a thermal converter 1, an analog adder 2, an integrator 3, a capacitor 4, a voltage-code converter 5, an adder 6, a register 7, a memory unit 8, a display unit including a decoder 9 and an indicator 10 and a control unit 11

Digital temperature meter works as follows.

The signal is in the form of voltage, which is proportional to the temperature from the output of the thermal converter 1 post

Claims (1)

A DIGITAL TEMPERATURE METER containing a voltage code thermal converter, a memory unit -! a display unit, which includes a decoder indicator, a series-connected adder and a register, the output of which is connected to the input of the adder, a control unit connected to a voltage-code converter, an adder, a recorder and a memory unit, characterized in that, in order to increase measurement accuracy while reducing the requirements for the voltage-to-code converter, an integrator, an isolation capacitor and an analog adder are introduced into it, the first input of which is connected to the output of the thermal converter, the second input through kondensato'r divider connected to the output of the integrator connected to the control unit, and an output connected to the input of inverter voltage - code whose output is connected to the second adder -Log, wherein the storage unit input coupled to the register output, and an output connected to the display unit. e) ap 1084624