This Pressure sensor is used to measure absolute pressure - the actual gas pressure at the port with respect to zero. 


The pressure is measured against a built-in internal vacuum reference. The sensor then produces an output voltage that varies with absolute pressure. 


The sensor measures accurately between 20 to 400 kPa linearly.


Values below 20 kPa are slightly non-linear and may be not so reliable.


If the port is left open to the atmosphere, the sensor will display the value for atmospheric pressure, also known as barometric pressure, which is pressure caused by the downward force of the Earth’s gravity pressing the air down on the Earth. 


The average pressure exerted at sea level by the atmosphere in Britain is 101.325 kPa (1 atmosphere). 


  • This Pressure sensor measures absolute pressure - the actual gas pressure at the port with respect to a built-in internal vacuum reference. 
  • The sensor then produces an output voltage that varies with absolute pressure.   
  • The sensor measures accurately between 20 to 400 kPa in a linear fashion. 
  • Values below 20 kPa are slightly non-linear and may be not so reliable.  
  • If the port is left open to the atmosphere, the sensor will display the value for atmospheric pressure, also known as barometric pressure, which is pressure caused by the downward force of the Earth’s gravity pressing the air down on the Earth.   
  • The average pressure exerted at sea level by the atmosphere in Britain is 101.325 kPa (1 atmosphere). 
  • The barb on the Luer connectors supplied with the Gas Pressure sensors will fit PVC or Silicon tubing with an internal diameter of 3 mm (1/8”).  
  • A Gas Pressure Accessory Kit, Product No.1149, is available which contains a selection of tubing elements and connectors which allow gas tight connections to these Gas Pressure sensors. Only use these sensors to measure non-corrosive/non-ionic media such as air or dry gases.  
  • This sensor is not suitable for use with flammable gases. 
  • A small amount of lubricant on tubing and connectors will make the tubing slide on more easily. 
  • The vapour pressure of liquids can be monitored but do not allow liquid to enter the sensor. 
  • Protect from the weather – keep the sensor dry. 
  • The container used with the Pressure sensor must be suitable for the task and able to sustain the pressure. The type of container selected will depend on the investigation. 
  • A non-flexible airtight container like a syringe could be used for quantitative investigations e.g. pressure vs. volume.  
  • Gas contained in a system under pressure will try to find a way out. The longer the investigation lasts, the more dominant the effect of any leaks will become - try to complete the investigation as quickly as it allows.  
  • The sensor is not waterproof. It may be cleaned using a damp cloth. Do not immerse in water or detergent. Do not place the sensor in an environment in which high humidity levels are possible as this may result in damage or malfunction. 

Units of Measurement

Pressure is defined as force per unit area and the standard SI unit of pressure is the pascal (Pa).


The conversion from kPa to mBar is simply to multiply by 10. (1 kPascal = 10 millibar = 0.14504 psi).


1 Pascal = 1 Newton per square meter (1 N/m2).


Equivalent values for 1 atmosphere are = 101.325 kPa = 760 mmHg = 29.92 in. of Hg (at 0oC) = 14.70 PSI = 1013 millibar.