Liquid vs. Dry Pressure Gauges: What's the difference?
There are two main types of pressure gauges. Today, we will go over why you might consider investing in a liquid filled gauge vs a dry one. Dry pressure gauges
are the work horse of the industrial and commercial parts world. Look at most air compressors. Many industrial machines and even some of the fancier bicycle pumps will have a dry gauge. Dry gauges do have some drawbacks, though. The dial can become obscured by moisture inside the gauge. If the temperature drops low enough, the moisture can convert to ice, causing a total failure from the device.
So, what about liquid-filled pressure gauges? Do they perform differently?
Yes Do They If dry gauges are work horses, then liquid-filled pressure gauges are like the Budweiser Clydesdales, doing the same job but with greater precision and yeah, I'll say it...style. Liquid-filled pressure gauges
are available in pressure ranges equal to or higher than their dry counterparts. Their casings are filled with fluid, usually glycerine, although silicone or other liquids are sometimes used. The liquid coats the internal parts and is visible on the gauge's face. Having the liquid inside works to dampen the effect of pulsation and pressure spikes - which is another advantage over choosing a dry gauge. This means the pressure gauges are less likely to give inaccurate readings due to wear and tear that mechanical vibration and pulsation tends to cause. The liquid in these pressure gauges does double duty when it comes to fighting those effects. Not only does it help mitigate the effect of vibration, the liquid also lubricates the gauge's moving parts, reducing everyday friction. The filling also has the benefit of preventing internal corrosion. As the bourdon tube and movement are covered by a liquid that keeps moisture and other corrosive substances at bay. All of those factors add up to longer service life and lower replacement costs for liquid-filled pressure gauges over dry pressure gauges. And in environments where vibration and condensation are a factor, they are definitely a consideration