What Is a Differential Pressure Gauge?
A differential pressure gauge measures pressure differences in fluids. It assesses the pressure disparity between two distinct points, quantifying and displaying the difference. It typically features two ports: one measuring fluid pressure at a specific location and the other at a reference point. The gauge then displays the pressure difference.
Applications of Differential Pressure Gauges
Differential pressure gauges find applications across various sectors:
- Clean Rooms: Installed atop doors to maintain high internal pressure, preventing external contaminants.
- Liquid Level Measurement: Measures pressure difference at different levels in tanks and reservoirs, useful in boilers and pressure vessels.
- Gas Leak Detection: Monitors gas pipelines and tanks for abnormal pressure changes.
- Filter Monitoring: Measures pressure differences indicating filter clogging, prompting maintenance or replacement. Bug filters, for example, are often equipped with a differential pressure gauge, which is used to monitor the clogging of the filter cloth.
Principle of Differential Pressure Gauge
Differential pressure gauges vary in design. A common type, the manometer, utilizes hydrostatic pressure to gauge differences:
1. For Liquids:
Pressure differences are ascertained through liquid height and spring deformation. A glass tube filled with liquid alters height based on pressure differences, which can be read off a scale.
2. For Gas:
Gas pressure differences are measured by the deformation of a spring or diaphragm. This displacement is translated into a pressure difference, displayed digitally or via an analog scale.
Types of Differential Pressure Gauge
Besides manometers, there are other types:
1. Pitot Tube Type:
Utilizes fluid velocity pressure to measure pressure difference, estimating fluid velocity and flow rate.
2. Orifice Plate Type:
Measures flow velocity and rate through a plate in a pipeline, calculating pressure differences.
3. Differential Pressure Transmitter:
An electrical device converting pressure differences into analog or digital signals, using pressure sensors and integrated circuits for signal processing.