Wax Thermal Actuator And Various Types Of Temperature Sensors
Wax thermal actuator has a function to change energy by automatic transmission after the induction of temperature changes. The mechanical action of the wax actuator comes from thermal expansion material that is not affected by the surrounding environment. Wax actuators are applied in temperature regulation and control systems with the advantage of being able to make adjustments to temperature with a wide range. Actuators, sensors, and transducers are elements of an automation system. Sensors and transducers in the automation system function to sense physical quantities in a process. It can simply be said as process parameters in the form of pressure, level, flow, specific gravity, and temperature. Sensor and Actuator systems are often known as control systems.
Temperature Sensors are components that can convert heat into electricity, so they can detect signs of temperature changes in certain objects. Temperature sensors take measurements of the amount of heat energy or cold energy produced by an object. The temperature sensor is part of the transducer. Examples of equipment that uses a Temperature Sensor are; Room and Body Temperature Thermometers, Refrigerators, Rice Cookers, Air Conditioners, and more.
Types Of Temperature Sensors
Temperature sensors have different characteristics and functions. Here are some types of temperature sensors:
Thermostats are Contact Temperature Sensors that use the principle of Electro-Mechanical and consist of two different types of metals. Both types of metal are attached, thus forming a Bi-Metallic strip that can bend if you get a certain temperature. The process will be able to move to disconnect or connect the circuit, which is to make the position ON or OFF. Thermostats are used in equipment in the form of Oven, Water Heater, and Iron. The induction of temperature changes also correlates with the wax thermal actuator.
A thermistor is an electronic component whose resistance value is affected by temperature. This temperature change is closely related to the ax thermal actuator. The thermistor consists of two types, namely Positive Temperature Coefficient (PTC) and Negative Temperature Coefficient (NTC). In PTC the value of resistance will increase when the temperature is high, whereas in NTC the value of resistance decreases when the temperature rises high. Thermistors can convert electrical energy into resistance. Thermistors are made of semiconductor materials, such as; Cobalt, Nickel Oxide, Manganese coated with glass. Thermistor has the advantage of having a fast response to temperature changes.
Thermistors are also cheaper than the Resistive Temperature Detector (RTD) Temperature Sensor. The range of thermistor resistance ranges from 2,000 Ohm – 10,000 Ohm. Thermistor also has a high-temperature sensitivity. PTC or NTC type thermistors are widely applied in electronic equipment, including temperature sensors in refrigerators, temperature sensors in computers, fire detectors, and various other electronic equipment.
- Resistive Temperature Detector
Resistive Temperature Detector (RTD) has the same function as PTC type Thermistor, which converts electrical energy into electrical resistance, proportional to temperature changes. Resistive Temperature Detector is more precise and has high accuracy when compared to PTC type Thermistor. Resistive Temperature Detector is made of Platinum. This RTD type temperature sensor has a wide temperature range. Can operate in temperature conditions of -200 degrees Celsius to +650 degrees Celsius. The results are more precise, accurate, and stable. The temperature sensor also has to do with the wax thermal actuator.
A thermocouple is the type of temperature sensor that is most often applied because it has a wide range of Thermocouple operating temperatures. The temperature range ranges from -200 degrees Celsius to more than 2.000 degrees Celsius. Thermocouple also has a lower price. A thermocouple is a Thermo-Electric temperature sensor that has a different metal junction. The condition is one of the metals in the Thermocouple is kept constant which acts as a reference junction. Meanwhile, for other metals, heat is subject to be detected. The difference in temperature in the two intersections makes the circuit will produce a certain voltage with a value proportional to the temperature of the heat source.
The advantage of using Thermocouple is that it has a very wide temperature range and is resistant to vibrations and shocks. Also, the thermocouple can provide a direct response to changes in temperature. After the induction of changes in temperature, the energy can be changed by a wax thermal actuator.