A process pressure gauge is used to measure that is used to measure pressure. It’s also possible to use the phrase pressure indicator. Pressure, along with temperature, is the most recorded as well as regulated process parameter in industry, hence pressure gauges may be found almost wherever. Pressure sensors are not included in this buying guide. Pressure gauges, unlike sensors that create an electronic signal and therefore must be linked to a machine or a control system in order for their measurement to be readable or useable, enable the pressure reading to also be viewed immediately on a dial as well as digital display. Many pressure gauges are entirely mechanical, while others involve the use of electricity.
When talking about pressure measurement, it’s crucial to understand what pressure will be evaluated. Pressure gauges can measure three basic forms of pressure: absolute, relative, and differential. Pressure gauges as well as sensors work by turning the distortion of a material (membrane or other) caused by the pressure to be recorded into a numerical value. The pressure differential between the two sides of this surface causes it to deform. Solely on a single side is the pressure to be measured, but on the other is a standard pressure. The sort of pressure getting recorded as well as the kind of pressure gauge employed are both determined by this reference pressure.
Gauges with an analogue display versus gauges with just a digital display are the two types of pressure gauges.
Analog pressure gauges
Analog gauges employ a mechanical technique to move a needle on some kind of dial under pressure, while liquid column gauges are still used in some settings.
- They don’t need a power source; thus they may run continually without needing to replenish batteries or install a power supply.
- They are well-built and intended to withstand shocks and vibrations, allowing them to be utilized in a wide range of industrial applications, even in harsh environments.
- They make it possible to see the pressure level quickly.
- Their reading is less precise and prone to mistakes (e.g. parallax errors).
- They can’t be employed inside a process control since their measurements aren’t accurate enough.
Digital Pressure Gauges
Digital pressure gauges comprise a circuit design that requires electricity to transform the pressures into more of an electrical signal and show the reading on a screen.
- The digital display makes reading values simple and accurate.
- They have additional functionality thanks to its electronics, such as the ability to select the system of measurement, save maximum values, and so on.
- They can have an output to connect to a control system.
They demand batteries or a continuous power supply.
Dry and Liquid filled Process Pressure Gauges
Owing to the mechanism that converts the distortion of the sensor element into a rotating movement for the pointer, Process pressure gauges having dials are susceptible to tremors as well as pressure surges or decreases. Flooding the pressure gauge enclosure entirely with liquid has been shown to be a solution to this issue. As a result, while selecting a pressure gauge, evaluate whether you require a dry versus liquid-filled kind.
There is no liquid in dry pressure gauges.
- Dry pressure gauges are much less costly than liquid-filled pressure gauges.
- Dry pressure gauges are much more cost-effective and favored in basic operations where vibrations are not a concern. For example, they’re frequently seen on air compressors.
- They are not shielded against vibrations, pressure surges, or dips, which might cause the mechanism to fail.
- They are not ideal for use in cold or wet locations because water vapor within the gauge housing might freeze, causing the mechanism to malfunction.
The casing of a liquid-filled pressure gauge has been entirely filled with a liquid (typically pure glycerin or a combination of water and glycerin) that acts as an absorber for vibrations as well as pressure spikes or decreases.
- Liquid-filled pressure gauges are more resilient to vibration as well as pressure spikes or drops.
- They are airtight, so moisture cannot enter the casing and obstruct the mechanism.
- Sub-zero temperatures are no problem for this sort of pressure gauge.
- Since the liquid (glycerin) is non-toxic and otherwise decomposes, they are ecologically beneficial.
- Liquid-filled pressure gauges are utilized in damp and chilly conditions, as well as in situations where there is a lot of vibration.
- A pressure gauge loaded using pure glycerin may operate at temperatures as low as -5°C. Below 17°C, glycerin becomes viscous, slowing the mechanism, and below -5°C, the pressure gauge is entirely blocked.
- A blend of glycerin plus water is utilized for low temperatures, allowing the pressure gauge to resist temperatures as low as -46°C.
Is it better to have a fixed or a portable pressure gauge?
Although the question may appear basic, there are indeed portable as well as static pressure gauges accessible, and you must select between the two based on your requirements. Portable pressure gauges, which are frequently electronic, enable for precise readings and management in industry and laboratories. Fixed pressure gauges, whether mechanical or electronic, enable for constant pressure management in industrial operations.