Platinum resistance temperature measurement circuit

Abstract

The invention provides a platinum resistor temperature measuring circuit, which comprises a measuring circuit and a platinum resistor, wherein the measuring circuit comprises an isolation power supply, a reference power supply circuit, a first current source generating circuit, an optical coupling isolation circuit and a second current source generating circuit, the reference power supply circuit, the first current source generating circuit, the optical coupling isolation circuit and the second current source generating circuit are sequentially connected, the input end of the isolation power supply respectively provides power supply for the input ends of the reference power supply circuit, the first current source generating circuit and the optical coupling isolation circuit, the output end of the isolation power supply respectively provides electricity for the output end of the optical coupling isolation circuit and the second current source generating circuit, one end of the platinum resistor is connected with the low-level end of the input end of the isolation power supply, and the other end of the platinum resistor is connected between the first current source generating circuit and the optical coupling isolation circuit. The platinum resistor temperature measuring circuit has the advantages that the resistance value is converted into current signals, through lines, the current signals are transmitted to a sampling circuit, and the current signals collected by the sampling circuit are conveyed to a CPU (central processing unit) to be calculated for obtaining the temperature of an object to be measured, so the temperature measurement and the use are more convenient, the current signals are transmitted in the lines, and the anti-jamming capability is obviously enhanced.

Description

technical field [0001] The invention relates to temperature measurement technology, in particular to a platinum resistance temperature measurement circuit. Background technique [0002] The invention relates to a temperature-measuring circuit, which is suitable for all temperature-measuring application fields using platinum resistors as temperature-measuring resistors. Within a certain temperature range, the platinum resistance value can change linearly with the temperature. Therefore, platinum resistance thermometers are widely used in the field of temperature measurement where the temperature range is not very large. Usually, the platinum resistance is made into a resistance value of 100 ohms, and the temperature measuring circuit with a 100 ohm platinum resistance as a temperature measuring resistance is called a PT100 temperature measuring circuit. The following takes PT100 as an example to illustrate the existing temperature measurement circuit [0003] The tradition...

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