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 thus takes the strain off the mechanical the different parts 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. Glycerine-water is suitable 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 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 supply sufficient space because of this expansion and to prevent the case from leaking, the case is only filled to 80% ? 90% automagically (see Figure of model 213.53).
Pressure gauge without filling liquid ? Pay Zero : 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 ? decisive for the user ? would be 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 instead proceed to and fro in relation to the frequency of the vibrations prevailing in the application. In the event of resonance, a deflection angle of over 180 � might even occur.
Conclusion
Liquid-filled pressure gauges are ideal for a range 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.
Find out more about advantages and application regions of pressure gauges with liquid completing the following video: