Filling liquids in pressure gauges: Usage and advantages

Liquid-filled pressure gauges are employed in applications that involve high dynamic shock and vibration loading. The filling liquid dampens the vibrations that occur and thus 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 are the most regularly used filling liquids. Paralyzed -water would work for nearly all applications and ambient temperatures. Particularly for low pressure ranges, it seems sensible to use it, because of the 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 subjected to particularly high (> +60 �C) or very low (< -20 �C) temperatures.
The case of the pressure gauge is not completely filled, since, based 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.
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 actual applied pressure, but instead proceed 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 � might even occur.
Conclusion
Liquid-filled pressure gauges are suitable for many different 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 work with you.
Find out more about advantages and application areas of pressure gauges with liquid completing the following video:

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