摘要
现有的温度测量电路受热电偶输出电压极小且线性度差的影响,普遍只能在较小范围内实现单点温度测量,并且测量精度不高,难以满足实际应用需求。本系统通过优化设计,克服了以上缺陷,实现了较大范围的多点温度精确测量。该系统选用低失调高精度运算放大器ADOP07组成同相并联型差动放大电路,对热电偶进行非电测量;选用CD4051芯片构成分时切换电路,以实现温度多点测量;采用AD538芯片组成平方运算电路,以进行温度线性补偿;最后将测量数据通过A／D转换器送单片机进行数据处理,运用现代模糊控制理论进行控制以达到精密测量和控制目的。通过实践检验,本系统实现了在20～400℃宽范围内的多点温度精确测量,实验结果令人满意。
Owing to the influence of extremely little output voltage and the poor linear degrees of thermocouple on measuring temperature, the existing hardware circuits can only measure a single point temperature in a small range, and it is difficult to meet the demand of practical use with its low measurement precision. Using optimization design to overcome the above-mentioned defects, this system realizes accurate measurement of multipoint temperature in a large range. It uses low maladjustment and high precision operation amplifier ADOP07 to constitute the inphase and shunt-wound difference amplification circuit to carry out non-electric measurement of thermocouple, uses the CD4051 chip to compose the switch circuit at different time in order to realize the measurement of multi-thermocouple, and uses the IC AD538 to implement square operation in order to make linear compensation of temperature, finally sends the measurement value to single-chip computer through A/D converter to process data, which is controlled by the application of modern fuzzy controlling theory so as to reach the aim of precise measurement and control. The experiments show the system can realize accurate measurement of multipoint temperature in a wide range from 20 to 400℃, and the experimental results are satisfying.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2006年第z2期1707-1709,共3页
Chinese Journal of Scientific Instrument
关键词
热电偶
非电测量
差动放大
线性补偿
thermocouple non-electric measurement difference amplification linear compensation
