Design Of Temperature Detection System And Error Analysis

Human society entered the information age from the industrial age. In the information age,the most important thing is access to information. Despite the times changing, Remain the same,the temperature parameters as an important information, Temperature measurements are required in various fields. Temperature detection pattern mainly divided into: contact and non-contact temperature measuring. In practice, it needs according to the specific situation to choose the right temperature measuring method. Despite the current temperature measurement detecting instrument on the market emerge in endlessly, with the improvement of production technology level, the accuracy of measurement is becoming more and more high, but the temperature of the high precision, wide range, multi channel detector, the price is very expensive, so the design of reliable,economic, simple, multi-channel temperature detection system has practical application significance.The designed of temperature detection system in this paper, its temperature detection range from 190 ℃ to 230 ℃, and the requirement of error should less than plus or minus ± 2℃, by compared with different models, J type thermocouple is the ultimately selection as the temperature sensor. To ensure the accuracy of the system, the design of temperature detection circuit should make the voltage signal into a linear output with the temperature, and make sure that the slope of temperature detection circuit is 10 mV / ℃. Through experimental analysis, the temperature detection circuit can achieve accuracy requirement of the system, and the absolute error among0.3~1.3℃, the relative error is range from 0.2% to 0.62%. In this paper, temperature data can be circulation collected by single-chip STC89C58 RD and control multi-channel A/D conversion chip TLC2543.In the software design process, use a gross error culling method as primary filter,and use extremum average filtering method as secondary filter.Temperature detection system testing in a simulated temperature field in the incubator,Multiple sensors placed at random. Absolute error of 15 channel temperature measurement sensor placement is 0.1 ~ 0.2℃. Select error 15 path maximum calculated error of temperature detection system. It follows that, Absolute error of the system is: 0.4~1.5℃, relative error of the system is0.21~0.68%.In order to further improve the accuracy of the system, using the least square error correction system, after correction, And according to the characteristics of the system measurement system uncertainty analysis, the results show that the system has higher accuracy.