摘要
目前在低温(<0℃)状态下尚无能同时对温度、压力、湿度进行标定的现成产品,基于双温双压原理该文研制了一套温、压检定系统,以实现对传感器和仪器设备同时进行温度和压力的标定;在给出系统结构、工作原理的基础上,建立了温度系统和压力系统的数学模型,给出了bang-bang控制和改进PID(proportional-integral-differential)的复合控制方法,最后进行了现场试验,试验结果表明:在系统的绝对压力为30～130kPa,温度为-70～80℃时,温度测量绝对误差<0.02℃,压力测量绝对误差≤15Pa,温度控制绝对误差<0.03℃,压力控制绝对误差≤18Pa,温度和压力的目标确定度分别为0.06℃和10Pa,结果表明该检定系统具有控制精度高、稳定性强和可靠性高的特点,可用于检定、地面仪器考核、探空仪器考核。该研究为进一步研究温、湿、压综合检定系统提供技术手段和试验数据。
PTU devices （devices measuring pressure, temperature and humidity simultaneously） was typically applied to weather observation systems, wrist computers, study of humidity generation technology and calibration of metering equipment. At the moment, a number of sensors or equipments are directly exposed to severe and complex environment conditions, so more comprehensive environmental parameters are inevitably affected by the surrounding environment when these sensors or equipments are working. With the peripheral environment change, not only accuracy and reliability of these sensors or instruments are hard to ensure, but also they can＇t work when the environment changes beyond sensor or instrument calibration range. Hence, to obtain more comprehensive data of sensors or equipments, a set of device or system which can be used to measure pressure, temperature and humidity simultaneously is urgently required. However, it is pity that there are hardly any commercial calibration systems to be available for low temperatures （0℃） for the PTU devices at present. As for this situation that there are absent for commercial calibration systems which can be used to calibrate the temperature, pressure and humidity simultaneously at low temperatures （0℃）, a new high-precision temperature and pressure calibration system was developed based on the two-temperature and two-pressure humidity generation principle. In this temperature and pressure calibration system, pressure and temperature can be controlled simultaneously. On the one hand, the temperature and pressure calibration for sensors and apparatus can be achieved simultaneously, on the one hand, it can provide the theoretical basis and more comprehensive experimental data for the further research of the calibration system of temperature, pressure and humidity. After introducing the structure of the system and operating principle, mathematical models of temperature system and pressure system were developed, and compound control strategy of bang-bang and improved PID （proportional-integral-differential） was given. Finally, field tests were carried out. Experimental results indicated that when the absolute pressure is from 30 kPa to 130 kPa and temperature is from -70℃ to 80℃, temperature measurement absolute error and control absolute error were less than 0.02℃ and 0.03℃, respectively; measurement absolute error and control absolute error of pressure were less than 15 Pa and 18 Pa, respectively; The target uncertainty （k=2） of the temperature and pressure are 0.06℃ and 10 Pa, respectively. These results further showed that the calibration system had the advantages such as high control precision, strong stability and high reliability. This calibration system can be used to calibrate sensors and apparatus as well as evaluate ground equipments and radiosonde instruments.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2013年第A01期38-45,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家公益行业重大专项(GYHY2007060003)
国家自然基金创新群体项目资助(61121003)
关键词
标定
温度测量仪器
压力测量
系统
湿度
calibration
temperature measuring instruments
pressure measurement
systems
humidity
