Analog and Differential Pressure Gauges

Dial pressure gauges, also known as analog pressure gauges, are measuring instruments used to detect the pressure of fluids, such as gases or liquids, in a wide range of industrial applications.
These devices work simply and reliably, thanks to a mechanism that transforms the pressure detected into a mechanical movement visible through a pointer on a dial.

How do dial pressure gauges work

Dial pressure gauges are direct pressure gauges, whose operating principle is based on an elastic primary element. This component, when subjected to pressure, deforms proportionally to the applied force.
The deformation is transmitted to a pointer that moves on a graduated scale, indicating its value. The pressure reading is therefore immediate and visible on the dial.
The elastic elements used can vary depending on the pressure range to be measured.

Among the most common are:
- Bellows: used for relatively low pressures, they are able to compress or expand precisely based on pressure variations.
- Capsules: ideal for measuring low differential pressures, they are formed by two circular surfaces connected to each other.
- Diaphragms: used to measure both high and low pressures, these thin surfaces deform when exposed to pressure variations.
- Tubular springs (or Bourdon): mainly used for high pressures, they are made of an oval section tube that deforms and moves when pressurized.

Applications in critical conditions

In some applications, the fluids to be measured can be aggressive, corrosive, toxic or operate at extreme temperatures, outside the normal operating limits for the elastic element.
In these cases, it is necessary to use protection devices called fluid separators (or diaphragm separators).
These components act as barriers between the process fluid and the sensitive element of the pressure gauge, protecting it from damage or corrosion.
The separation fluid, usually a special oil, transfers the pressure to the pressure gauge without there being direct contact with the fluid to be measured. This allows the use of pressure gauges in particularly critical environments, preserving their precision and durability over time.

Differential Pressure Gauges

Differential pressure gauges are a specific type of pressure gauge designed to measure the difference in pressure between two points within a system.
They are widely used in monitoring filters, hydraulic and pneumatic circuits, and in processes that require the control of small pressure changes.
The difference in pressure is measured directly and displayed on the dial, making this type of gauge essential for ensuring precise monitoring of complex systems.
Due to their versatility and robustness, analog and differential pressure gauges are widely used in industries such as industrial manufacturing, chemical, pharmaceutical, and process automation, offering a simple and effective solution for pressure monitoring.