DPS or Differential pressure switches is a device used to actuate an electric switch based on differential pressure across two points and this electric switch used to sense airflow status
components of Differential pressure switches
Range – The span of differential pressures or flow rates within which the sensing element of a given switch can be set to actuate an electric switch.
Set or Actuation Point – The exact air pressure or flow rate which will cause the electric switch to actuate.
Rated Pressure – The maximum pressure that the actuating components of the switch in contact with the media can withstand continuously and/or repeatedly without risk of permanent damage.
Maximum Surge Pressure – Safe pressure for the switch housing but which may damage the mechanism by the continuous or repetitive application.
Normally Open Switch – A Switch in which the contacts are normally open. Actuation closes the contacts.
Normally Closed Switch – A switch in which the contacts are normally closed. Actuation opens the contacts.
Single Pole Double Throw (SPDT) Switch – A switch combining both normally open and normally closed switch contacts.
Null Switch – A floating contact switch with a zone of no contact. Often used to operate reversible motors.
Repetitive Accuracy – The ability of a pressure or flow switch to operate repetitively at its set point under consistent conditions.