Radiation temperature sensor

A radiant temperature sensor is a sensor that is used to measure the temperature of objects by the radiation they emit. It is based on the principle that all objects with a temperature above absolute zero (-273.15 °C) emit electromagnetic radiation. This radiation is detected by the radiant temperature sensor and converted into an electrical signal that can then be used for temperature measurement. Radiation temperature sensors are often used in industrial applications to measure the temperature of hot surfaces or melting furnaces, as they work without contact and are therefore safer and more practical than conventional temperature sensors.

A radiant temperature sensor, also known as an infrared temperature sensor, is based on the principle of infrared radiation. It measures the temperature of an object by detecting the infrared radiation emitted by this object.

The sensor consists of a lens that focuses the infrared radiation of the object to be measured and a detector that measures the radiation. The lens ensures that the radiation is focused onto the detector.

The detector consists of a material that reacts to infrared radiation, such as a semiconductor layer. When the radiation hits the detector, it generates an electrical voltage or current. The level of the voltage or current is proportional to the intensity of the infrared radiation and therefore to the temperature of the object.

The measured voltage or current is then processed by a microcontroller or other evaluation unit and converted into a temperature display. Depending on the application, the temperature can either be displayed directly or sent to other devices for further processing.

A radiant temperature sensor has the advantage that it works without contact and is therefore also suitable for measurable objects that are not easily accessible or in motion. It is also suitable for measuring high temperatures or in environments where direct contact with the object may be undesirable or dangerous, such as in industry or medicine.

There are various types of radiant temperature sensors, including

1. Thermocouples: Thermocouples consist of two different metals that are welded together at one end. When the welded end heats up or cools down, it generates an electrical voltage that is proportional to the temperature change.

2. Infrared thermometer: This type of temperature sensor measures the temperature using the infrared radiation emitted by an object. They detect the radiation and convert it into a temperature display.

3. Pyrometer: Pyrometers measure the temperature of an object by detecting the heat radiation it emits. They use various techniques such as optical measurements or radiation detectors to determine the temperature.

4. Resistance thermometer: Resistance thermometers use the relationship between electrical resistance and temperature. They are made of a metal whose resistance increases as the temperature rises. The temperature can be calculated by measuring the resistance.

5. Semiconductor temperature sensors: These sensors use special semiconductor materials whose electrical resistance is strongly dependent on temperature. The temperature can be determined by measuring the resistance.

6. Fiber optic temperature sensors: These sensors are based on the use of optical fibers that absorb heat and change their optical attributes when heated. The temperature can be calculated by measuring these changes.

Radiation temperature sensors are used in various areas in which the temperature of surfaces or objects is to be measured by radiation. Some typical areas of application are

1. Industry: Radiant temperature sensors are often used in industry to monitor the temperature of machines, furnaces, crucibles, melting or heating processes. They enable non-contact measurement of the surface temperature and are therefore particularly useful in situations where direct measurement is not possible or safe.

2. Building technology: In building technology, radiant temperature sensors are used to monitor the temperature of radiators, underfloor heating or solar thermal systems. They can also be used to detect heat loss on building facades or to monitor temperature differences in different rooms.

3. Medical applications: In medicine, radiant temperature sensors are used to monitor the body temperature of patients. They enable non-contact measurement of skin temperature and are therefore particularly suitable for use with babies, children or people with sensitive skin.

4. Climate and environmental monitoring: Radiation temperature sensors are also used to monitor the ambient temperature in air conditioning systems, greenhouses or meteorological applications. They can help to identify temperature differences and optimize the efficiency of heating and cooling systems.

This list is not exhaustive, as radiant temperature sensors can be used in many areas where non-contact temperature measurement is required.

The use of radiant temperature sensors offers a number of advantages:

1. Fast and accurate measurements: Radiant temperature sensors enable fast and precise measurement of the surface temperature of objects without the need for direct contact. This saves time and makes it possible to carry out measurements even in places that are difficult to access.

2. Non-invasive: Radiant temperature sensors measure the surface temperature of an object without touching or damaging it. This is particularly advantageous for sensitive or fragile materials.

3. Wide range of applications: Radiant temperature sensors can be used in various areas, e.g. in industry, construction, food processing and medicine. They are suitable for both quality control and process monitoring.

4. Contactless working: Due to the non-contact measurement, radiant temperature sensors can also be used in areas where direct contact with the measured object should be avoided for safety reasons, e.g. at high temperatures or in hazardous environments.

5. Versatility: Radiant temperature sensors can be used to measure different types of surfaces, regardless of their color or texture. They deliver accurate results regardless of external influences such as humidity or air movement.

6. Easy handling: Most radiant temperature sensors are portable and easy to use. They do not require complex calibration or maintenance, which makes them easier to use and deploy in different environments.

Radiant temperature sensors are very accurate in their measurement and enable non-contact temperature measurement of objects. They are based on the principle of infrared radiation, which is emitted by an object and converted into heat.

The accuracy of the measurement depends on various factors, such as the quality of the radiation thermometer, the distance between the sensor and the object to be measured, the emissivity of the object and any interference from surrounding radiation sources.

Modern radiation thermometers are highly accurate and can generally measure temperatures with a deviation of a few degrees Celsius. The measurement can also be improved by using calibration techniques to further increase accuracy.

Radiation temperature sensors, also known as infrared temperature sensors or pyrometers, are usually calibrated by comparison with a reference standard.

There are various methods of calibrating radiant temperature sensors, but the most common method is to use a blackbody. A blackbody is an object that completely emits all the radiation it absorbs. A well-known blackbody is, for example, a blackbody radiator.

During calibration, the radiant temperature sensor is placed in a known temperature range while the blackbody maintains a constant temperature. The radiation temperature sensor measures the radiation emitted by the black body and outputs a corresponding temperature display. This reading is then compared with the actual temperature of the blackbody to determine the accuracy of the radiant temperature sensor.

It is important that the ambient conditions are kept stable during calibration to ensure accurate measurement. This includes controlling factors such as humidity, air flow, background radiation and other environmental variables.

Calibration should be carried out regularly to ensure that the radiant temperature sensor provides correct and accurate readings. The frequency of calibration depends on the specific application and the requirements of the device.

The following safety aspects must be observed when using radiant temperature sensors:

1. Radiation exposure: Radiant temperature sensors work by measuring the infrared radiation of objects. Direct exposure to strong radiation sources can lead to burns or other injuries. It is therefore important not to point the sensor directly at strongly radiating objects.

2. Laser class: Some radiant temperature sensors use lasers to measure the radiation. In this case, the laser class must be observed. Class 2 or higher lasers can cause eye damage if they are aimed directly into the eyes. It is therefore important not to point the sensor at the eyes and to check the laser class.

3. Electrical safety: Radiant temperature sensors are often operated with electrical energy. It is important to ensure that appliances are properly grounded and have appropriate safety measures such as grounding conductors to minimize the risk of electric shock.

4. Ambient temperature: Radiant temperature sensors can react sensitively to extreme temperatures. It is important that the ambient temperature is within the specified operating range to ensure correct measurement and safe operation of the device.

5. Radiation protection: Special care must be taken when using radiant temperature sensors in areas with ionizing radiation, such as in the nuclear industry. In such environments, suitable radiation protection measures must be taken to ensure the safety of personnel.

It is important to read the operating instructions for the respective radiant temperature sensor carefully and to follow the specified safety measures to ensure safe use.