The difference among pressure sensor, pressure relay and pressure switch

Pressure sensor is composed of pressure sensitive element and conversion circuit, which uses the pressure of the medium under test to produce a small change of current or voltage output on the pressure sensitive element. Sensors often need to be used with external amplifying circuit to complete the process from pressure detection to control and display. Because the pressure sensor is a primary component, the signal feedback from the pressure sensor needs to be processed, analyzed, stored and controlled by the measurement and control system, so as to make the industrial automation equipment and engineering operation control more intelligent.

Pressure relay is a signal conversion element of the hydraulic switch which uses liquid pressure to open and close the electrical contacts. It is used to send out electrical signal to control the action of electrical components when the system pressure reaches the set pressure of relay, realize the control of pump loading or unloading, sequence action of the executive element, safety protection and interlock of the system, etc. It is composed of pressure displacement conversion part and microswitch. According to the structure types of pressure displacement conversion components, there are four types: plunger type, spring type, diaphragm type and bellows type. Among them, the plunger structure is divided into two types: single plunger type and double plunger type. The single plunger type can be divided into three types: plunger, differential plunger and plunger lever. According to the contact, there are single contact and double electric shock.

Pressure switch is a function switch which automatically turns on or off when the set value is reached according to the set pressure.

Pressure switch, pressure relay, can only be opened or closed under the pressure you set, used for simple bit control, are switch output! Pressure relays provide more output nodes or node types than pressure switches. The output of pressure sensor can be analog signal or digital signal. The post-processing is convenient, and it can also be used for remote transmission.