Pressure thermometer is made by the principle that the working medium (gas, vapour or liquid) in the sealed container changes the pressure with the change of temperature. Pay attention to the following problems during use and installation:
1) the meter reading of the pressure thermometer of the inflatable body or liquid is not only related to the temperature of the temperature package, but also affected by the temperature of the capillary and spring tube, that is, affected by the temperature of the surrounding environment, although some compensation methods are adopted, the influence of environmental temperature cannot be completely compensated. Therefore, the variation range of environmental temperature during use is stipulated. Pay attention to this problem in practical use.
Fang, the static pressure of the liquid acts on the manometer, which produces reading error and should be corrected.
It is inappropriate to measure the temperature close to room temperature. Because the measured temperature fluctuates around room temperature, the vapour in the capillary and spring tube vaporize for a while and condense for a while, which cannot reflect the change of temperature correctly and timely.
When using, the temperature must not exceed the upper limit of its measurement. Once the temperature is exceeded, all the liquid in the temperature package will be vaporized. At this time, the vapor pressure is no longer the saturated vapor pressure. Therefore, the relationship with the temperature response has changed, and the measurement result must be inaccurate, even the instrument will be damaged due to the violent expansion of the vapour.
3) the capillary of the pressure thermometer is easy to break and leak, and be careful not to lay it in the place which is easy to be damaged and worn when installing. After selecting the appropriate position to slightly tighten it, fix it with a clip and protect it with angle iron. The Turning position can not be a right angle. Capillary should not approach or contact with high temperature heat source such as steam tube.
