在热力发电厂中 ,对反映机组热力工作介质状态的压力、温度、流量、液位等热工参数的准确测量 ,是保障机组安全、经济运行必不可少的一个重要环节。为提高热工测量的准确性和可靠性 ,不少电厂在热工仪表的配备上费尽心机 ,甚至不惜耗费巨资 ,加快仪表更新速度 ,使用高精度、高 In the thermal power plant, accurate measurement of the thermal parameters such as pressure, temperature, flow rate and liquid level, which reflect the status of thermal working medium in the unit, is an essential part of ensuring the safety and economic operation of the unit. In order to improve the accuracy and reliability of thermal measurement, many power plants have devoted themselves to the equipping of thermal instruments and have even spent huge amounts of money to speed up the updating of instruments. The use of high precision and high