In industrial processes, measuring temperature is often the most important variable to control because it changes the chemical or physical state of most substances and has a great impact on cost.
There are two ways to measure the temperature of an object. One way is to have the sensor in direct contact with the object or fluid and the other way is to measure the radiation or emitted energy of the object with an infrared sensor. Both methods are widely used in industrial heating applications.
Examples of contact temperature sensors are thermocouples, RTD's and Thermistor's. A thermocouple can measure the widest temperature range, RTD’s are excellent sensors for repeated measurements and highly accurate. The basic thermistor can be very accurate for a limited temperature range and produced very cost-effective.
Infrared temperature sensors (pyrometer, spectralmeter, infrared thermometer) measure the temperature without contact to the object. For many applications contact devices are too inaccurate, too slow or difficult to use (example moving parts), so infrared thermometers are the better choice. All object "broadcast" or radiate information about their temperature all the time. The infrared sensor measures how many watts per square centimeter the object radiates and then calculates the temperature. Different materials have different emissivity, which can also vary with temperature. A versatile infrared sensor collects the data with more than one wavelength. Dual- and multi-wavelength sensors can measure temperature through steam, dirty windows, or fog to measure temperature of objects.
Please to discuss your application.
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