Difference and Relation between Differential Pressure Switch and Pressure Switch
We can say that the differential pressure switch is a pressure switch, but we cannot say that the pressure switch is a differential pressure switch. So, what's the difference between a pressure switch and a differential pressure switch? What is the relation between the differential pressure switch and the pressure switch?
First of all, as for their relationship, they are all pressure instruments that trigger the switch action through pressure and then output the switch signal to control the device. Their output signals may be the same or different. Both the pressure switch and the differential pressure switch may have one or two set values.
The difference between pressure switch and differential pressure switch is mainly reflected in the structure and principle:
1. Differences in structure:
(1) the pressure switch adopts the pressure sensor and transmission circuit with high stability and accuracy, and then realizes the detection, display, alarm and control of the medium pressure signal output through special CPU modular signal processing technology.
(2) the differential pressure switch is composed of two pressure elements with high sensitivity. If the pressure difference between the two ends is changed by changing the pressure at both ends, the switch action will be triggered and the switch mechanism will act as a control device such as an electric valve. The switching mechanism provides the SPDT with a "non-fast action (floating) action" so that the common movable contact will touch one of the two fixed contacts or stay between them (no contact switch signal).
2. Different working principles:
(1) when the pressure in the system is higher or lower than the rated safety pressure, the intima of the sensor will immediately move and push or disconnect the switch connector by connecting the guide rod. When the rated pressure drop to recover value or to rise to the rated recovery value, the diaphragm will immediately reset, and the switch will automatically reset, or only in the measured pressure exceeds rating, displacement of the free end of the elastic element can directly, or after pressing the switch element by comparison, change the on-off state switching element, achieve the goal of control pressure.
(2) differential pressure switch is composed of two pressure Chambers, two sealing septum and a differential pressure membrane. The high pressure and low pressure respectively enter the high pressure chamber and low pressure chamber of the differential pressure switch. The difference of the two pressures deforms the pressure sensing film. Through mechanical structures such as armrest springs, the top microswitch finally begins to output electrical signals.