• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
SensorsONE

SensorsONE

Measurement Instrumentation Products

  • Products
  • Tools
  • Contact

Measuring negative pressure using a positive differential pressure range

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.

Differential pressure measurement products
  • 1.5 psi wet/wet DP transmitter for line pressures up to 1,885 psi
  • Biogas HDPE cover PD blower pressure sensor
  • -3 to 4 mbar dp range 4-20mA ATEX approved biogas pressure sensor for process control use on a 1bar line
  • 1.5 inWG differential pressure transducer to control positive pressure inside a building

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.

Differential pressure measurement products
  • Biogas HDPE cover PD blower pressure sensor
  • DMD331 Compact Differential Liquid Pressure Sensor
  • 5 psi dp 0-10V out air pressure sensor for automation flow rate testing use on a 15psi line
  • DPS Low Differential Pressure Transmitter 0.1 inH2O differential range 0-10Vdc output between rooms air pressure sensor

Measuring negative pressure using a positive differential pressure range

Differential pressure measurement products
  • 901 Prescal Series Pressure Switch 901 Prescal Pressure Switch Specification and Data Sheet
  • Plenum chamber differential pressure transmitter with 100 mmWG range
  • PD39X High Differential Pressure Transmitter PD39X High Differential Pressure Transmitter
  • -3 to 4 mbar dp range 4-20mA ATEX approved biogas pressure sensor for process control use on a 1bar line

Primary Sidebar

Help Guides

  • Measuring negative pressure using a positive differential pressure range
  • Pressure Sensor Accuracy Specifications
  • Process Connections
  • Determining calibration error of Bourdon tube pressure gauge
  • Measurement Accuracy
  • Supply voltage and load resistance considerations for pressure transmitters
  • Measuring vacuum with negative gauge or absolute ranges
  • What is the difference between gauge and absolute pressure measurement
  • Measuring the difference in air pressure between rooms
  • How to Connect a 4-20mA Current Loop Pressure Transmitter
  • Advantages and Disadvantages of using a 4 to 20 mA Signal
  • Determining water tank volume using hydrostatic pressure
  • How do you measure the volume of a liquid using pressure
  • What is the difference between vacuum and absolute pressure
  • What does negative and positive gauge pressure mean

Featured Product Types

  • Intrinsically Safe Pressure Data Loggers
  • Chemical Resistant Hydrostatic Liquid Level & Pressure Sensors
  • Pressure Sensors for Data Logging with a Computer
  • Computer Interface Pressure Gauges
  • RS485 Serial Interface Pressure Sensors
  • Vacuum Pressure Transducers

Product Enquiry

Send us your enquiry for a product associated with this Measuring negative pressure using a positive differential pressure range page, and get assistance with selecting a product for your application.

Email Your Enquiry

enquiries@sensorsone.com

© 2023 SensorsONE Ltd, all rights reserved

  • Home
  • Products
  • Tools
  • Legal
  • Contact