The Role of Oil in Oil-filled Pressure Gauge

Some pressure gauges contain oil, others do not. Is there any difference between them? There are some differences, but they are not very different, just the difference in the use of the two occasions. What is the effect of the oil in the pressure gauge?

In fact, the resistance increases after oil filling, so the pointer is relatively stable, which can prevent the vibration of the needle. That is to say, the shock-proof pressure gauge is usually used in harsh environments (such as noisy environments), or the pressure fluctuation in the system (such as plunger pumps) makes the pressure gauge read accurately. To extend the service life.

Is this "oil" optional? The answer must be NO! This "oil" is mainly composed of glycerol and silicone oil. The effects of the two oils are different. Glycerol mainly plays an anti-seismic role; silicone oil can also play an anti-seismic role, but silicone oil can withstand low temperature more than glycerol. If the outdoor temperature reaches minus 20 C, glycerol will crystallize, but silicone oil can also make the instrument work normally.

So both glycerol and silicone oil can be used, but at least two points should be taken into account when making specific choices: 1. thermal expansion coefficient, the smaller the coefficient, the better, this is mainly affected by temperature; 2. In the use of occasions, the food industry can not use these two oils, in case the diaphragm damages the oil will pollute the food. It is not recommended to measure strong oxidizer, otherwise it will cause explosion.