What Are the Differences between Sensors and Actuators?

 

What are sensors and actuators? What the difference between them? Sensors and actuators may seem indistinguishable, but in fact there is a big essential difference. It is also working in an industrial environment, the sensor is responsible for monitoring the working conditions of the equipment, and the actuator is responsible for driving things in the equipment. The two often interact, but they are two different components. The two complement each other in work and work together to ensure the effective operation of the equipment.

 

The sensor monitors environmental conditions, such as fluid level, temperature, vibration, or voltage. When these environmental conditions change, they send electrical signals to the sensors, and the sensors can then send data or alarms back to the central computer system, or adjust the functions of specific equipment. For example, if the motor reaches an overheating temperature point, it will automatically shut down.

 

The actuator is an essential part of the automatic control system. Its function is to accept the control signal sent by the controller and change the size of the controlled medium, so as to maintain the controlled variable at the required value or within a certain range. According to their energy form, actuators can be divided into three categories: air powered actuator, hydraulic actuator and electric motor actuator.

 

Differences between Sensors and Actuators

 

Sensors and actuators track different signals, operate in different ways, and must work together to complete tasks. They are also physically located in different areas and are often used in separate applications. Sensors are responsible for tracking data entering the machine, while actuators perform actions.

 

1. Input and Output

 

Sensors look at inputs from the environment, which trigger specific actions. On the other hand, the actuator tracks the output of the system and the machine.

 

2. Electrical signal

 

The sensor reads specific environmental conditions through electronic signals and performs assigned tasks. However, the actuator measures heat or motion energy to determine the effect.

 

3. Dependence

 

Sensors and actuators can actually depend on each other to perform specific tasks. If both are present, the actuator will rely on the sensor to complete its work. If one or both of them fail to work properly, the system will fail to operate.

 

4. Change direction

 

Sensors tend to convert physical properties into electrical signals. The effect of the actuator is opposite, changing the electrical signal into a physical action.

 

5. Location

 

If there are both sensors and actuators, the first one is at the input port and the latter is at the output port.

 

6. Application

 

Sensors are usually used to measure asset temperature, vibration, pressure or liquid level. Industrial applications of actuators include operating dampers, valves and couplings. Common valves mainly include pneumatic ball valve, electric ball valve, actuated butterfly valve and motorised butterfly valve.

 

Use of Actuators and Sensors

 

The actuator mainly includes 5 different types. Manual actuators require employees to control gears, levers or wheels. Although they are cheap and easy to use, they have limited applicability. The compact pneumatic actuator uses air pressure to power the valve. The pressure pushes the piston to affect the valve stem. Hydraulic actuators use fluid to generate pressure. Hydraulic valve actuator does not use air pressure, but hydraulic pressure to operate the valve. The electric motor actuator uses an electric motor to operate the valve. Although these actuators are quiet and efficient, they require batteries or electricity and may not always be available in certain locations. The spring return actuator will keep rebounding until the trigger occurs. Once a certain threshold is reached, the spring will release and operate the valve. These are usually used in disposable emergency applications.

 

Sensors mainly include temperature sensors, vibration sensors, safety sensors, pressure sensors, humidity sensors and gas sensors.

 

In short, although actuators and sensors often work together, they are very different components in an industrial maintenance system.