Hydraulic/Pneumatic Pressure Measurement and Control

2026-04-02

I. Application in Hydraulic Systems:

In hydraulic systems, sensors primarily address issues related to pressure fluctuations, such as energy consumption, loss, and safety hazards.

Pump and valve closed-loop control

Sensors are installed at the pump outlet or valve block, transmitting 4-20mA signals back to PLC or frequency converters. For example, in a constant pressure system, real-time adjustment of motor speed can reduce energy consumption by over 25%, while controlling injection pressure can increase product qualification rate from 92% to 98.5%.

Pressure peak monitoring and equipment protection

During the start-up and shutdown of the hydraulic system, "water hammer effect" can occur, damaging the pipeline. Sensors must have a response speed of 1ms or less and overload capacity to capture instantaneous high pressure and trigger safety interlocks or shut down the equipment.

Fault prediction and health management

Monitoring pressure differences can determine filter blockage; if the pressure build-up time becomes longer, it indicates possible internal leakage or pump wear, thus transforming post-maintenance repair into predictive maintenance.

II. Application in Pneumatic Systems

Pneumatic systems focus on cleanliness and speed. Sensors are mainly applied in vacuum grasping and flow control.

Vacuum grasping and material handling

In robot palletizing or injection part retrieval, sensors are directly installed near the suction cup to monitor vacuum level. Only when the pressure reaches the set threshold will the system allow the robot to move, effectively preventing materials from falling midway.

Leakage monitoring and energy management

The cost of compressed air is high. Sensors can monitor the rate of pressure drop in the air path. If the pressure drops rapidly during the pressure maintenance stage, the system will determine the presence of a leak point and trigger an alarm.

Precise force control and flexible contact

In precision assembly, closed-loop control of output force is used to avoid damaging precision components (such as electronic components or glass products).

III. Special Conditions and Harsh Environments

Hydraulic and pneumatic systems are often in extreme environments, which impose special requirements on sensors.

Heavy loads and construction machinery

Such as steel mills' continuous casting machines or mining machinery, the environment is filled with high temperatures, vibrations, and oil stains. Sensors must have an IP69K protection level, a stainless steel housing, and a wide temperature working range of -40°C to 125°C, with a total error band (TEB) controlled within ±2% to ensure reliable data.

Explosion-proof and clean areas

In petrochemical or coal mining applications, intrinsically safe (Ex ia) sensors are used to prevent explosions; in food and pharmaceutical industries, hygiene interfaces are required, without dead corners and corrosion-resistant, facilitating cleaning.