Filling liquids in pressure gauges: Usage and advantages

Liquid-filled pressure gauges are used in applications that involve high dynamic shock and vibration loading. The filling liquid dampens the vibrations that occur and therefore takes the strain off the mechanical components of the pressure gauge.
Pressure gauge with filling liquid ? model 213.53
Usage of filling liquids
With respect to the operating conditions, glycerine-water mixtures or silicone oils will be the most frequently used filling liquids. Glycerine-water would work for the majority of applications and ambient temperatures. Particularly for low pressure ranges, it makes sense to use it, as a result of low density of the liquid and the associated low resistance on the pressure element. Silicone oil is primarily relied upon when the pressure gauge is subjected to particularly high (> +60 �C) or very low (< -20 �C) temperatures.
The case of the pressure gauge isn’t completely filled, since, based on humidity and ambient temperature, the filling medium absorbs additional water and expands accordingly. To supply sufficient space because of this expansion and to avoid the case from leaking, the case is only filled to 80% ? 90% by default (see Figure of model 213.53).
Instantly without filling liquid ? result: vibrating pointer
Advantages of filling liquids
The filling liquid dampens any pressure peaks, shocks and vibrations that occur and protects the mechanics of the pressure gauge. Thus, material fatigue and malfunction is counteracted.
A further factor ? decisive for an individual ? is to ensure the readability of the prevailing pressure. The filling liquid causes the pointer?s motion to be limited, even under severe vibration loads. Without liquid damping, the pointer wouldn’t normally show the specific applied pressure, but instead proceed to and fro with regards to the frequency of the vibrations prevailing in the application form. In case of resonance, a deflection angle of over 180 � could even occur.
Conclusion
Liquid-filled pressure gauges are suitable for a number of applications, specifically processes involving shock and vibration.
Note
Should you need any more help or advice for your specific application, your contact will be glad to assist you.
Find out more about advantages and application regions of pressure gauges with liquid filling in the following video:

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