Bimetallic thermometer is the difference between oil filled with no oil filled?1

Bimetallic thermometer is the difference between the oil filled and no oil filled, mainly used in the occasion, the difference between the oil filled bimetallic thermometer is mainly used in the environmental vibration, without oil filled bimetallic thermometer, namely common bimetallic thermometer, mainly used in ordinary places. 'Oil' in those metal thermometer to what effect? Actually, the main purpose of the bimetallic thermometer oil charge is in order to reduce external vibration environment disturbance to the pointer, achieve the goal of ensure the sensitivity of the thermometer. Then you can choose either the 'oil'? The answer is definitely NO! The 'oil' is mainly glycerin and silicone oil. Two kinds of oil have different role, glycerin is mainly the seismic effect; Silicone oil can also have the effect of the seismic, silicone oil is more tolerance for low temperature than glycerol, however, if the outdoor temperature reached minus 20 ℃, glycerin is crystallized, but silicone oil can make the instrument work normally. So glycerol and silicone oil of these two kinds of oil can be used, but in the concrete choice at least when considering the two points: 1, the coefficient of thermal expansion, coefficient as small as possible, this mainly affected by temperature; 2, the use of occasions, the food industry both oil can't use, one thousand damage to diaphragm oil can contaminate food. Also do not recommend using measuring strong oxidizer, otherwise it will cause explosion.