Ultra-high accuracy temperature measurement method

Abstract

The invention discloses an ultra-high accuracy temperature measurement method. A bridge circuit composed of a temperature sensor and a constant voltage source converts a temperature signal into a fitting capacitance value F1. The phase-locked voltage PDV1 of the PD phase detector unit is applied to a variable capacitance diode to form the fitting capacitance value F4. All the fitting capacitance values form a total fitting capacitance value F in series and parallel. The fitting capacitance value F is connected to a VCO unit and added to a PD phase detector unit by a capacitor C2 to act as oneof the frequency signals to be compared and compared with the other path of frequency signal arranged in a reference crystal oscillator and CPU, SCL and SDA communication lines and finally a stable phase-locked voltage PDV1 is generated. The difference between PDV1 and the base voltage PDV0 is the measured value of PDV. The measured value is sent to the CPU for processing and converted into a realtemperature value for display or communication. The problems of non-linearity, temperature drift, sudden interference and uncertain drift of open loop control technology can be solved and ultra-highaccuracy temperature measurement can be realized.

Description

technical field [0001] The invention relates to a temperature measurement method, in particular to an ultra-high precision temperature measurement method. Background technique [0002] Temperature measurement, especially ultra-high-precision temperature measurement technology, has a wide range of applications in the fields of measuring instruments, industrial control, medical instruments, and deep space exploration. Regardless of the application in the embedding of the product itself, or in the calibration and calibration of the product's R&D and manufacturing process in terms of accuracy, resolution, and repeatability, temperature measuring instruments play an important role. The traditional temperature measuring instrument uses a temperature sensor plus an operational amplifier, A / D conversion, reference voltage module and CPU processor, etc. Due to the influence of temperature drift, device drift factors and nonlinear factors of the device or circuit, the temperature meas...

AI Technical Summary

Problems solved by technology

The traditional temperature measuring instrument uses a temperature sensor plus an operational amplifier, A / D conversion, reference voltage module and CPU processor, etc. Due to the influence of temperature drift, device drift factors and nonlinear factors of the device or circuit, the temperature measuring instrument It is difficult to achieve ultra-high indicators such as precision and resolution, and the consistency of the products produced is not high

Although the lock-in amplifier measurement technology is now used in the temperature measuring instrument, its accuracy and resolution have been greatly improved, but the lock-in amplifier uses the open-loop phase-locked phase detection technology to measure the temperature signal, which is still affected by nonlinearity, temperature Drift, sudden interference and uncertainty drift of open-loop control technology, resulting in the improvement of accuracy and resolution is still less than the goal of ultra-high indicators

Images