It is not advisable to measure temperatures close to the room temperature. Because the measured temperature fluctuates around the room temperature, the vapour in the capillary tube and spring tube vaporises for a while and condenses for a while, which does not reflect the change in temperature correctly and in time.
The temperature must not exceed its upper measurement limit when in use. Once exceeded, all the liquid in the temperature package vaporization, the vapor pressure is not saturated vapor pressure, so the relationship with the temperature response has changed, the measurement results are certainly inaccurate, and even due to the violent expansion of the vapor and damage to the instrument.
The capillary tube of the pressure type thermometer is prone to fracture and leakage, and care should be taken when installing it not to lay it in a place where it can be easily damaged and worn out. After selecting the appropriate location slightly stretched, fixed with clamps and protected by angle iron, the bend must not become a right angle. The capillary tube should not be close to or in contact with high temperature heat sources such as steam pipes.
