How can you use a differential pressure measurement device to measure a negative pressure if it has been factory configured to measure a positive pressure range without making any adjustments to the electronics or the signal output?
Finding a pressure sensor to read negative pressure can be difficult since the vast majority of pressure measurement devices are only available with positive ranges as standard, since most applications require a positive pressure range, and therefore manufacturers understandably focus on the most popular pressure ranges for their product range.
Although manufacturers will often consider a custom configuration for measuring negative pressure, this could cause a delay to delivery and an extra cost compared to the standard pressure range configuration.
- 200 bar gradient pressure sensor with RS232 for use on oil
- Vacuum pump inlet to outlet differential pressure sensor with 1500 Torr range
- Clean room temp, RH and pressure monitoring
- 0-100Pa air pressure transducer with a 0-10V analog output
There is a much simpler and convenient solution to measuring negative pressures. A differential pressure measurement device has two separate pressure connections so that the difference in pressure between the two connections can be measured. One connection will be marked as High (Hi) or Positive (+), and the other as Low (Lo) or Negative (-).
Typically when measuring positive pressures, the Low side connection would be open to ambient air pressure, and the High side connection would be connected to the positive pressure to be measured.
If you want to measure negative or suction pressure instead, you can reverse the connection, so that the High side connection is open to ambient air pressure, and the Low side connection is connected to the vacuum pressure. As the vacuum increases, the greater will be the difference in pressure between the Low and High side.
As an example, a 0 to +100 mbar differential pressure range will become a 0 to -100 mbar differential pressure range simply by reversing the connections.
- Negative room pressure monitor and logger for multiple zones
- 2 bar water pressure difference sensor and single input process indicator
- -15psig 0-10V out negative pressure transducer and display for air extraction use
- 15,000 Pa DP Transmitter with built-in digital display
- Ethylene glycol antifreeze compatible 300 pascal dp sensor
- Negative room pressure monitor and logger for multiple zones
- Minus 0.25 inWG differential pressure transmitter for negative air pressure difference
- 2 bar water pressure difference sensor and single input process indicator
Related Help Guides
- Measuring vacuum as a negative gauge pressure using a dp sensor
- How do you measure flow rate with a dp cell
- Measuring liquid level in a tank using a dp sensor
- Can you have a minus 20 psi gauge vacuum measurement range
- Measuring density of a liquid using a dp sensor
- Measuring the difference in air pressure between rooms
- Measuring vacuum with negative gauge or absolute ranges
- What is the difference between vacuum and absolute pressure
- Can you measure vacuum using a gauge pressure range
- What does negative and positive gauge pressure mean
- What can a DP sensor be used to measure beyond differential pressure?
Related Technical Terms
Related Online Tools
- DP Flow Transmitter Output Calculator
- High and Low Side Pressure to Differential Pressure Calculator
- Suction Pressure to Vacuum Calculator