Working principle of pressure switch
Pressure switch is a simple pressure control device, consisting of a pressure sensor and a control circuit, when the measured pressure reaches the rated value, the pressure switch can issue an alarm or control signal.
Pressure switch – intelligent digital pressure switch
The working principle of the pressure switch is: when the measured pressure exceeds the rated value, the free end of the elastic element produces displacement, directly or after comparison to push the switching element, change the on-off state of the switching element, to achieve the purpose of controlling the measured pressure.
The elastic components used in the pressure switch include single-coil spring tube, diaphragm, diaphragm box and bellows.
The switching elements are magnetic switch, mercury switch, micro switch and so on.
The switching form of the pressure switch has two types: normally open and normally closed.
There are two ways to adjust the pressure switch and three way.
Accuracy: A value indicating the accuracy of the equipment, including linearity, tolerance, hysteresis, repeatability, etc.
Maximum pressure (Max.P) : The maximum value of the pressure range.
Full scale (F.S) : The difference between the maximum and minimum of the pressure range.
Break difference (dead range) : refers to the difference between the set action value and the reset value of the switch. For example, if the set value is 1MPa and the actual reset value is 0.9MPa, the break difference is 0.1MPa.
Operating temperature: refers to the temperature range of the internal mechanism of the instrument, sensitive components, etc., when working without continuous deformation. The recommended operating temperature range of the general pressure switch is -5~400C, if the medium temperature is too high, you can consider adding an accessory siphon (irrigation) to achieve the purpose of cooling.
S.P.D.T (single pole double throw) : consists of a normally open, a normally closed contact and a common end.
D.P.D.T (double pole double throw) : consists of a symmetrical left and right common end, and two groups of normally open and normally closed terminals.
Upper limit one contact (normally open) : When the pressure rises to the set value, the contact acts and the circuit is switched on.
Lower limit one contact (normally closed) : When the force drops to the set value, the contact acts and the circuit is switched on.
Upper and lower limit two contact HL: is a combination of upper and lower limit type, divided into two contact independent action (double setting, double circuit) and two contact simultaneous action (single setting, double circuit) two types.
Upper limit 2 contact: The combination of two upper limit forms, divided into two contact independent action and two contact simultaneous action of two types.
Lower limit 2 contact: The combination of two lower limit forms, divided into two contact independent action and two contact simultaneous action two types.
Pressure resistance: The maximum pressure that the pressure switch can withstand to maintain its normal performance. However, when the pressure switch is used in overpressure situations, the sensitive element will cause continuous deformation, then the pressure setting value will change, and the pressure switch will not play its normal performance and may even be damaged.