宽温压力可变标准湿度发生器的研制

采用双温双压法原理研制了一套宽温度范围、测试室压力可变的标准湿度发生器。它能够测量发生温度范围为-50～90 ℃、相对压力范围为-50～0 kPa、扩展不确定度为0.3%RH～0.8%RH（k=2）的5%RH～96%RH全量程相对湿度。其测试室尺寸为150 mm×400 mm,样气流量为5～30 L/Min。通过设计高精度饱和器压力和流量自动调节装置,采用工控机与PLC相结合的操作控制方式,实现了全自动运行。冷镜式精密露点仪和重量法湿度计的实际测试结果均验证了其不确定度。

The Development of a Standard Humidity Generator with Large Temperature Range and Adjustable Chamber Pressure

With two-temperature and two-pressure principle,a standard humidity generator with large temperature range and test chamber pressure adjustable is developed.It can generate the whole range relative humidity in the temperature range of -50～90 ℃ and the relative pressure range of -50～0 kPa with the estimated expanded uncertainty of 0.3%RH～0.8%RH(k=2).The inner size of the test chamber is 150 mm×400 mm.The flow rate of the sample gas is 5～30 L/min.Automatic operation in the generator has been realized by using the working and control mode in which the industrial control computer and PLC is combined and by designing the device which can control the saturator pressure and sample gas flow accurately.The test results of cool mirror dew-point hygrometers and a gravimetric hygrometer proved its uncertainty.