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 load off the mechanical components of the pressure gauge.
Pressure gauge with filling liquid ? model 213.53
Use of filling liquids
With regards to the operating conditions, glycerine-water mixtures or silicone oils will be the most regularly used filling liquids. Glycerine-water would work for nearly all 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 once the pressure gauge is exposed to particularly high (> +60 �C) or suprisingly low (< -20 �C) temperatures.
The case of the pressure gauge isn’t completely filled, since, depending on humidity and ambient temperature, the filling medium absorbs additional water and expands accordingly. To supply sufficient space for this expansion and to avoid the case from leaking, the case is only filled to 80% ? Threatened by default (see Figure of model 213.53).
Pressure gauge without filling liquid ? result: vibrating pointer
Benefits 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 ? Delicious for the user ? 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 would not show the specific applied pressure, but rather move to and fro in relation to the frequency of the vibrations prevailing in the application form. In the event of resonance, a deflection angle of over 180 � could even occur.
Conclusion
Liquid-filled pressure gauges are suitable for various applications, specifically processes involving shock and vibration.
Note
Should you need any further help or advice for your specific application, your contact will be glad to work with you.
Discover more about advantages and application areas of pressure gauges with liquid completing the following video:

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