1. High temperature range

The temperature measurement range of capillary thermometer is 200~650℃ (also clearly recorded in the encyclopedia), and the allowable error is about 1% of the scale range. In fact, this is not right, because this kind of metal sheet is made into a spiral-shaped heat conduction sensor, which is easy to fatigue at a high temperature of 650℃, and the temperature difference is very large. Therefore, when the temperature exceeds 550℃, a thermocouple should be considered to solve this problem.

2. Low temperature range

It is clearly stated in the relevant information that the temperature range of capillary thermometer is 200~650℃ (this is not correct), and the low temperature can be measured to -40℃. In fact, this is not much, because the temperature calibration of capillary thermometer in the production is usually -20℃ (if low temperature is needed, if not, we usually mark 0℃ to the upper limit of the temperature required by the customer. Users in Beijing Fang District Sometimes -40°C is used, which can be done, but in the case of -40°C, it is necessary to consider whether the error can be accepted.

The difference between oil-filled and non-oil-filled capillary thermometer is mainly the difference between the two applications. Capillary thermometer is mainly used in places where the environment is vibrated.