On the Russian market of measuring instruments there are many types of thermometers (pyrometers). So let’s consider how to choose a pyrometer.
The devices differ in:
- Principle;
- Fulfillment,
- guidance System for the object.
Principle of operation
Pyrometers are divided into 3 main classes:
- Optical (disappearing filament);
- Spectral relationships;
- Energy.
Optical devices appeared first on the market. In the eyepiece optical system of the device (on the background) you can see the filament of an incandescent lamp. The user has rotated the appropriate regulator (heated thread) until the thread color with the color of the measured object. The “disappeared” thread is a criterion of the equality of its temperature and of the object. But large errors in the measurements and the impossibility of implementation in automated systems has led to the removal of such pyrometers.
The device spectral ratio is able to measure the temperature of an object relative to the intensity of its radiation in two different spectral intervals. They are equipped with two:
Receivers of the radiation;
- Amp;
- Converters analog-to-digital signal.
The cost of such thermometers are high, but there is no need to enter in the device (the main advantage) is the emissivity of the measurement object before measuring.
Energy thermometers are the most common devices that determine body temperature by the intensity of its radiation in the same spectral interval. They have half as many radiation receivers, amplifiers, converters, so they are cheaper spectral devices. But you have to enter before measuring the emissivity of the object, and it is often unknown and depends on:
- Spectral sensitivity of the pyrometer;
- state of the surface of the object.
- Material.
The most common portable pyrometers infrared pyrometers are the model BALTECH TL-0208C.
Version
Thermometers execution are divided into portable and stationary. Overall, fixed devices rigidly attached to the measuring point, characterized by high precision and continuous measurement (kruglosutochnyy the on-line monitoring).
Portable thermometers are used where it is impossible to use stationary equipment. It’s close
- Dangerous;
- Hot;
- Located in inaccessible places and so on.
guidance System
Available parallax and parallax devices. The feature of the first thermometer – mismatch to the optical axis of the guidance system with the optical axis of the instrument (offset a few inches, parallax). Therefore, the pyrometer is equipped with a parallax guidance system should direct slightly above the area where you want to measure. If the object is small, it is inconvenient.
The pyrometers of the second type are equipped with eyepiece. With its help, the operator sees the crosshairs, exactly matching the measuring range. Therefore, to measure the temperature of small objects is better to use parallax pyrometer.
Training in pyrometry
Training center of excellence and training by “BALTECH” company invites all interested professionals to our training courses TOP-104 “thermography and Pyrometry. Thermal methods of nondestructive testing”.