A temperature sensor circuit based on pt100 and its temperature measurement method

Abstract

The invention discloses a Pt100-based temperature sensor circuit. The circuit comprises a measurement module, a reading module, a conversion module and a display module; the measurement module includes a Pt100 resistor, a precision resistor and a bias resistor; the reading module is an AD7793 chip with a voltage source, an instrument amplifier and a current source which are arranged therein; power is supplied for the precision resistor and the Pt100 resistor through two reference current source output ports of the AD7793 chip respectively; a common voltage reference point is provided through the bias resistor; the Pt100 resistor forms temperature voltage through adopting a four-wire system connection method; the precision resistor circuit generates constant voltage; the temperature voltage and the constant voltage are connected with the positive input end and negative input end of the AD7793 chip respectively; and the AD7793 chip is used for acquiring and reading voltage between the differential analog input positive input end and differential analog input negative input end of the AD7793 chip; and the conversion module converts a voltage value into a temperature value and transmits the temperature value to the display module. The invention also discloses a temperature measurement method using the above temperature sensor circuit. The circuit has the advantages of high measurement precision, high sensitivity and small size.

Description

technical field

[0001] The invention relates to the technical field of temperature sensors. More specifically, it relates to a Pt100-based temperature sensor circuit and a temperature measurement method thereof. Background technique

[0002] From the perspective of use, temperature sensors can be roughly divided into two categories: contact type and non-contact type. The former is to make the temperature sensor directly contact with the object to be measured, while the latter is to keep the temperature sensor and the object to be measured at a certain distance. Measure the infrared rays emitted by the object to achieve the purpose of temperature measurement. Among the two types of temperature sensors, contact and non-contact, contact sensors are relatively used, and non-contact sensors are generally used in special occasions. Currently, the most widely used contact temperature sensors are pyroelectric sensors. Among them, those that convert temperature changes into resista...

Examples

Embodiment Construction

[0043] In order to illustrate the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments and accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not limit the protection scope of the present invention.

[0044] Such as figure 1 As shown, a temperature sensor circuit based on Pt100, its working principle is:

[0045] In the present invention, the circuit includes a measurement module, a reading module, a conversion module and a display module.

[0046] The measurement module includes a Pt100 resistor R t , precision resistor R c and bias resistor R bias, the reading module is an AD7793 chip with a built-in bandgap reference voltage source, a low-noise programmable gain instrumentation amplifier and a programmable curren...

technical field

[0001] The invention relates to the technical field of temperature sensors. More specifically, it relates to a Pt100-based temperature sensor circuit and a temperature measurement method thereof. Background technique

[0002] From the perspective of use, temperature sensors can be roughly divided into two categories: contact type and non-contact type. The former is to make the temperature sensor directly contact with the object to be measured, while the latter is to keep the temperature sensor and the object to be measured at a certain distance. Measure the infrared rays emitted by the object to achieve the purpose of temperature measurement. Among the two types of temperature sensors, contact and non-contact, contact sensors are relatively used, and non-contact sensors are generally used in special occasions. Currently, the most widely used contact temperature sensors are pyroelectric sensors. Among them, those that convert temperature changes into resista...

Examples

Embodiment Construction

[0043] In order to illustrate the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments and accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not limit the protection scope of the present invention.

[0044] Such as figure 1 As shown, a temperature sensor circuit based on Pt100, its working principle is:

[0045] In the present invention, the circuit includes a measurement module, a reading module, a conversion module and a display module.

[0046] The measurement module includes a Pt100 resistor R t , precision resistor R c and bias resistor R bias, the reading module is an AD7793 chip with a built-in bandgap reference voltage source, a low-noise programmable gain instrumentation amplifier and a programmable curren...

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