High-precision wide-range temperature measurement system

Abstract

The invention discloses a high-precision wide-range temperature measurement system. The high-precision wide-range temperature measurement system comprises a temperature sensor, a signal conditioning module, a channel switching selection module, a first-level differential amplification module, a second-level differential amplification module, an analog / digital conversion module, a signal acquisition and processing unit, an adjustable voltage reference module and a fixed voltage reference module. The change of multiple or single temperature sensor is subjected to signal conditioning and channel switching selection and is then differentiated and amplified with fixed voltage reference; the amplified signal is subtracted from the fed-back adjustable voltage reference and amplified, and is then converted into a digital value through a analog / digital converter; the signal acquisition and processing unit is used for carrying out feedback adjustment on the adjustable voltage reference according to the digital value and an algorithm to finish high-precision temperature measurement in a wide range. The high-precision wide-range temperature measurement system disclosed by the invention has the characteristics that the high-precision and wide-range temperature measurement can be finished by using a low-order-digit analog / digital converter, and the temperature measurement precision is improved in order of magnitudes on the basis of the low-order-digit analog / digital converter.

Description

technical field [0001] The invention relates to a high-precision and large-range temperature measurement system, which belongs to the field of industrial measurement and control. Background technique [0002] Platinum resistors, thermistors, AD590 and other temperature sensors are widely used in various temperature measurement occasions. The output signals of these temperature sensors are mostly resistance or current signals, and the back-end needs to be converted into voltage signals through conditioning or sampling circuits. Usually, these voltage signals need to be converted into digital signals by an analog / digital converter for corresponding processing, so the measurement range and measurement accuracy of the temperature sampling circuit are closely related to the accuracy of the analog / digital conversion circuit. [0003] For example: for the temperature measurement range of -55°C-125°C, if the measurement accuracy of 0.01°C is to be achieved, an analog / digital convert...

AI Technical Summary

Problems solved by technology

[0007] The technical problem of the present invention is: to overcome the deficiencies of the prior art, to provide a high-precision and large-range temperature measurement system, which uses a low-digit A / D converter to replace a high-digit A / D converter, and realizes temperature measurement at an increased temperature. The temperature measurement resolution and temperature measurement accuracy are improved at the same time, which solves the shortage of high-digital analog-to-digital converters in the existing aerospace field

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