Learn how a differential pressure sensor (dp sensor) can be used to measure a partial vacuum as a negative pressure relative to local surrounding air pressure.
Measurement & Instrumentation Guides
Guidance and reference articles for sourcing, setting up and using measurement equipment.
Measuring gauge pressure using a dp sensor
Differential pressure sensors can double as gauge pressure sensors. Here we will explain how a DP sensor is used to measure gauge pressure.
What does negative and positive gauge pressure mean
You may not be aware but nearly every pressure measurement device you are using has a positive or negative gauge reference.
Can you measure vacuum using a gauge pressure range
The most common type of pressure range for pressure measurement instrumentation is one which has a gauge reference. So if you want to measure vacuum pressure, it would be convenient to use a gauge pressure device which is the most widely available pressure range format.
Vented Gauge
Vented Gauge (VG) is a pressure referenced to atmospheric pressure via a vent path on the reverse side of the pressure sensing diaphragm.
Negative Gauge Pressure
Negative Gauge Pressure is the difference in pressure between any vacuum and atmospheric pressure. The maximum possible negative gauge pressure is always limited by the current ambient atmospheric pressure, which constantly varies, but is typically around 1 bar absolute.
Reference Pressure
Reference Pressure is the pressure present on the reverse or negative side of a pressure sensing element.
SG – Sealed Gauge
Sealed Gauge (SG) is a type of reference pressure measured relative to a fixed pressure of approximately 1 bar absolute.
Vented Cable
Vented Cable has a vent tube running through the inside of the cable to provide a vent path between the electrical connections at either end.
Gauge Reference Pressure
Gauge reference pressure is a pressure measured relative to atmospheric or barometric pressure. The most used pressure reference is gauge pressure which is signified by a (g) after the pressure unit (e.g. 30 psi g), and means that the pressure measured is the total pressure minus atmospheric pressure. There are two types of gauge reference […]
What does the suffix a, abs, d, dp and diff, g, rel and sg mean after the pressure units in a pressure range?
There is a loose convention across manufacturers for designating the type of reference that a pressure sensing device has, which can be confusing if you are unfamiliar with specifying this often overlooked but critical specification parameter.
What is the difference between gauge and absolute pressure measurement
Determining whether you need gauge or absolute reference pressure is a very important to selecting the right pressure range for a pressure instrumentation.
Measuring liquid level in a sealed tank with a hydrostatic pressure sensor
In order to measure the level of a liquid using a pressure sensor you must be able to subtract the pressure of the gas at the top of the tank.
Measuring vacuum with negative gauge or absolute ranges
There are two reference points for measuring a vacuum pressure.