What are the temperature measuring instruments used in induction heating furnaces?

Induction heating is characterized by fast heating speed, generally tens to hundreds of degrees Celsius per second, or even thousands of degrees Celsius per second. Such a fast heating rate cannot be measured with a general pyrometer, and the temperature must be measured with an infrared thermometer or an infrared optical fiber colorimeter. These thermometers have been used in the induction hardening production of ball screws, machine tool guides, petroleum pipes, and PC steel bars. They have been successfully used in closed-loop control on the PC steel induction hardening production line.

01-T6 Series Optical Innovative Thermometer 01-T6 Series Optical Innovative Thermometer is shown in Figure 8-62. The principle is that the optical fiber is mixed with different materials, the window wavelength is adjusted, and the spatial filtering effect of the optical fiber is used to make the incident light wave change from a spatial transient state to a spatial steady state, and select ultraviolet, visible light, and infrared operating bands according to the temperature of the heat source to achieve The best combination of the measured temperature, fiber selection and photoelectric conversion.

The temperature measurement range is 250 ~ 3000 ℃, the segmented basic error is 5% (the upper limit of the range), the resolution is 0.5 ℃, the response time is less than 1 ms, and the minimum measurement diameter is (mesh

When the mark distance is 250mm), there are a variety of specifications and measurement ranges. Generally, the range of 300 ~ 1200 ℃ or 500 ~ 1300 ℃ can be selected for induction hardening.

MS Infrared Thermometer MS Infrared Thermometer is shown in Figure 8-63. It works by

It measures the intensity of infrared radiation emitted by the target and calculates the surface temperature of the object. It is a non-contact thermometer. The MS infrared thermometer is a portable thermometer, weighs only 150g, and has a volume of 190mm x 40mm x 45mm. The temperature measurement range is -32~420℃ and -32~530℃, the response time is 300ms, and the temperature measurement accuracy is ±1%. In the field of induction heating, it can be used to measure tempering temperature.

1. Temperature measuring pen The temperature measuring pen uses two different temperature-changing pens to test the surface temperature of the workpiece. Two adjacent color-changing pens draw the test surface at the same time, and the paint on the temperature measuring pen changes color, indicating that the temperature is higher than the calibration temperature of the pen, while the paint does not change, indicating that the temperature of the test surface is lower than the calibration temperature of the pen. This kind of temperature measuring pen is still available in foreign companies. It is mainly used to measure the surface temperature of welded parts. It can also be used for induction tempering or self-tempering.