Differential pressure sensors can double as gauge pressure sensors. Here we will explain how a DP sensor is used to measure gauge pressure.
- Gauge pressure measures pressure relative to the atmosphere.
- Differential pressure sensors measure the difference between two pressures.
- A differential pressure sensor can be used as a gauge pressure sensor by leaving one side open to the atmosphere.
Featured differential pressure sensor products
Monitoring AHU cooling coil efficiency with a DP transmitter - Low-range differential pressure transmitter for integration with a USB data acquisition module to monitor the efficiency of AHU cooling coils, enabling a predictive maintenance schedule based on real-time data.
Wet / Wet Differential Pressure Sensors - Wet/Wet differential pressure transducers and transmitters which are compatible with liquids on both positive and negative side process connections.
Gauge pressure is the measurement of pressure relative to the surrounding atmospheric pressure. This is normally achieved by using a sensor which has the reverse side of the sensing diaphragm open to atmosphere via a reference tube or port.
A differential pressure sensor is designed for pressure to be applied to both sides, so the mechanical design and fittings are similar on both sides of the diaphragm.
Even though the reverse side connection of a dp sensor is designed to withstand a range of pressures, and protected against liquids in many cases, it is perfectly okay, despite its underuse, to leave the process connection open and vented to atmosphere.
When pressure is now applied to the forward side connection of the dp sensor, it will be measured relative to atmospheric pressure, operating in exactly the same way as a gauge reference pressure sensor.
Featured differential pressure sensor products
20 Pa DP range 0-10V output air pressure sensor for building management use - A low range 20 Pa range differential pressure sensor, ideal for monitoring filters, ventilation ducts, and HVAC systems in commercial and residential buildings.
DPS200 HVAC Differential Pressure Transmitter - Differential air pressure sensor with a 10 volt or a 4-20mA output for building ventilation applications. Ranges from 0 to 6 mbar up to 0 to 1000 mbar.
Here are the steps involved in measuring gauge pressure using a differential pressure sensor:
- Make sure that the reverse or negative side of the sensor is left open to the atmosphere.
- Connect the forward or positive side of the differential pressure sensor to the system to be measured.
- The pressure that you apply will be measured relative to atmospheric pressure.
- The sensor will output a value that corresponds to the gauge pressure.
Related Help Guides
- Measuring liquid level in a sealed tank with a hydrostatic pressure sensor
- Measuring vacuum with negative gauge or absolute ranges
- Measuring the difference in air pressure between rooms
- What is the difference between gauge and absolute pressure measurement
- What does negative and positive gauge pressure mean
- Measuring negative pressure using a positive differential pressure range
- Measuring vacuum as a negative gauge pressure using a dp sensor
- Measuring liquid level in a tank using a dp sensor
- Measuring density of a liquid using a dp sensor
Related Technical Terms
- Differential Pressure
- Dry/Dry
- Gauge Reference Pressure
- Negative Gauge Pressure
- Reference Pressure
- SG – Sealed Gauge
- Static Line Pressure
- Vented Cable
- Vented Gauge
- Wet/Dry
- Wet/Wet
Related Online Tools
- DP Flow Transmitter Output Calculator
- High and Low Side Pressure to Differential Pressure Calculator
- Gauge + Barometric to Absolute Pressure Calculator

