Electric contact pressure gauge
Electric contact pressure gauges are widely used in petroleum, chemical, metallurgy, power stations, machinery and other industrial sectors or in the matching of electromechanical equipment to measure the pressure of various fluid media without explosion hazard. Usually, the instrument can be used with corresponding electrical devices (such as relays and frequency converters) to automatically control and send letters (alarms) to various gas and liquid media of the measured (controlled) pressure through the instrument.
Structure principle:
The electric contact pressure gauge is composed of a measuring system, an indicating system, a magnetic-assisted electric contact device, a casing, an adjustment device and a junction box (plug seat). General electric contact pressure gauges are used to measure the positive and negative pressure of gas and liquid media that are not corrosive to copper and copper alloys. Stainless steel electric contact pressure gauges are used to measure the positive and negative pressures of gas and liquid media that are not corrosive to stainless steel. When the pressure reaches a predetermined value, a signal is sent, and the control circuit is connected to achieve the purpose of automatic control of the alarm.
The electric contact pressure gauge is based on the spring tube in the measuring system, under the pressure of the measured medium, forcing the end of the spring tube to produce a corresponding elastic deformation and a displacement, which is transmitted and amplified by the pull rod through the gear transmission mechanism. The indication (together with the contacts) will indicate the measured value on the dial one by one. At the same time, when it is in contact with the contact (upper or lower limit) on the set pointer (moving off or moving on), the circuit in the control system is disconnected or connected to achieve automatic control and generation. The purpose of the letter to the police.
Electrical principle:
Take the control of the compressor motor as an example: when the gas storage and filling pressure reaches the lower limit, it automatically opens, and when it reaches the upper limit, it automatically stops.
The control process is as follows: when the pressure reaches the lower limit (or low and low when starting up), the movable contact (power common terminal) of the electric contact pressure gauge is connected to the lower limit contact, the relay J1 acts and self-locks, and its normally open contact is closed. Drive J3, the motor is powered to run. When the pressure reaches the upper limit, the movable contact is connected with the upper limit contact, the relay J2 acts, its normally closed contact is disconnected, the power supply of J1 is cut off, its normally open point is disconnected, J3 is released, and the motor stops. In this way, the purpose of automatic control is achieved.
Product Category:
In view of this series of instruments not only have the characteristics of novel design, reliable structure, complete varieties and specifications, good action stability and strong adaptability, but also have the advantages of combined measurement and control, simple installation and small maintenance, therefore, it is generally no indication. , A pressure measurement and control instrument unmatched by a pressure controller with no switching difference adjustment and no external setting device.
In order to meet the different requirements of the measured objects (with requirements of shock resistance, corrosion resistance and explosion-proof, etc.), shock-resistant electric contact pressure gauges or corrosion-resistant electric contact pressure gauges and explosion-proof electric contact pressure gauges that meet the requirements can be selected.
