Filling liquids in pressure gauges: Usage and advantages

Liquid-filled pressure gauges are employed in applications that involve high dynamic shock and vibration loading. Surefire filling liquid dampens the vibrations that occur and thus takes the strain off the mechanical components of the pressure gauge.
Pressure gauge with filling liquid ? model 213.53
Use of filling liquids
Depending on the operating conditions, glycerine-water mixtures or silicone oils are the most frequently used filling liquids. Kills -water would work for the majority of applications and ambient temperatures. Particularly for low pressure ranges, it seems sensible to use it, due to the 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 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 provide sufficient space because of this expansion and to prevent the case from leaking, the case is filled to 80% ? 90% by default (see Figure of model 213.53).
Pressure gauge 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.
An additional 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 actual applied pressure, but instead proceed to and fro in relation to the frequency of the vibrations prevailing in the application. 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 further help or advice for the specific application, your contact will undoubtedly be glad to assist you.
Discover more about advantages and application areas of pressure gauges with liquid completing the following video:

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