What Is a Radiation Pyrometer?

The radiation pyrometer is designed and manufactured according to the function relationship between the radiant energy of the object in the entire wavelength range and its temperature. The radiation thermometer is used as a primary instrument, and the electronic potentiometer is used as a secondary instrument. The device has an aluminum alloy housing, the front is an objective lens, a thermopile compensation light barrier is installed in the housing, and a shift plate is arranged on the field light fence close to the thermopile. The function of the baffle plate is to adjust the irradiation to the thermopile The radiant energy of the product makes the product have a uniform division value. Eyepieces are installed on the detachable rear cover to observe the image of the measured object.

The radiation pyrometer is designed and manufactured according to the function relationship between the radiant energy of the object in the entire wavelength range and its temperature. The radiation thermometer is used as a primary instrument, and the electronic potentiometer is used as a secondary instrument. The device has an aluminum alloy housing, the front is an objective lens, a thermopile compensation light barrier is installed in the housing, and a shift plate is arranged on the field light fence close to the thermopile. The function of the baffle plate is to adjust the irradiation to the thermopile The radiant energy of the product makes the product have a uniform division value. Eyepieces are installed on the detachable rear cover to observe the image of the measured object.
The radiation pyrometer is designed and manufactured according to the function relationship between the radiant energy of the object in the entire wavelength range and its temperature. The radiation thermometer is used as a primary instrument, and the electronic potentiometer is used as a secondary instrument. With aluminum alloy housing, objective lens at the front, built-in housing
Radiation pyrometer is a non-contact simple radiation temperature measuring instrument. It measures the surface temperature of objects according to the principle of thermal radiation effect of objects. It is suitable for continuous measurement of various furnaces, high temperatures in the metallurgical, mechanical, silicate and chemical industry sectors. The temperature in pits, salt baths, etc., and other places where thermocouples are not suitable for installation, with appropriate display instruments, can indicate, record and automatically adjust the measured temperature.
The instrument is a fixed installation type. The temperature sensor can be used in an environment of 10 to 80 ° C. When the ambient temperature exceeds 80 ° C or the air medium contains water vapor, the smoke can be reduced by the aid of water cooling, ventilation and other auxiliary devices. Blow out the flue gas in the measurement channel to reduce the measurement error.
The temperature sensor auxiliary device is divided into light and heavy. Heavy-duty is used in the harsh environment. In order to prevent the flame or high-temperature furnace gas from the measured channel from burning out the instrument to burn the instrument, a flame prevention device is installed, which can automatically act in case of danger to protect the instrument. And issued an alarm signal.
Measurement range
Lens material
Allowed basic error
With display instrument
temperature range
difference
400 1000
600 1200
Quartz glass
(Index F1)
400 1000> 1000 2000
± 16
± 20
Electronic potentiometer
Digital display meter or millivolt meter
900 1400
1200 1800
K9 glass
(Index F2)
700 1400
900 1800
1100 2000
Normal working environment temperature of the temperature sensor: 10 80
Nominal distance coefficient: L / D = 20 (at L = 1000)
Nominal: L-working distance between the objective lens of the measured object temperature sensor
DEffective diameter of measured object
Indication value stabilization time of the temperature sensor: <4 seconds
Working distance of temperature sensor: 500 2000

Radiation pyrometer interference factors

The radiation pyrometer does not come into contact with the measured object during the measurement, and environmental factors at the installation site will greatly affect the measurement. The interference of external light refers to the incident light from the external light source incident on the measured surface and reflected into the measurement light. Such as sunlight when measuring outdoors, lighting light when measuring indoors, nearby heating furnaces and flames, etc. Set a shielding device for some fixed and unavoidable external light sources. If the shielding device works in a high ambient temperature and the shielding device synthesizes a new heat source, it needs to be cooled by water or air to reduce its radiation and change the measurement. Direction to avoid the exposure of external light.
The distance between the measured surface and the radiation thermometer during the measurement is called the optical path. In the air of the production site, there are water vapor, carbon dioxide, floating scum, smog, oil mist, dust, water vapor and carbon dioxide gas media. The absorption of radiant energy is selective, and the radiation energy of certain wavelengths It has the ability to absorb, but it is easy to transmit the radiant energy at other wavelengths. The absorption of radiant energy by scum, smoke, oil mist and dust is non-selective, but it is accompanied by scattering, which weakens the incident into the thermometer The radiant energy leads to measurement errors. You can use clean compressed air to sweep the light path to blow off the smoke. The salt bath furnace is often deoxygenated to remove slag to maintain the normal brightness of the salt surface.

Installation, use and maintenance of radiation pyrometer

The heating medium of the salt bath furnace is a molten liquid, which mainly relies on convective heat transfer. The temperature of the furnace is uniform. The temperature of the furnace can represent the temperature of the workpiece. The installation of the radiation sensor has a great influence on the accuracy of the temperature measurement.
First select a place that is easy to access and easy to maintain. The lens of the radiation sensor is 1m away from the surface of the salt bath. The lens of the temperature sensor is installed perpendicular to the liquid surface. The temperature of the casing must not be higher than 100 . If it is higher than 100 , the cooling water should be passed through the water-cooling device to reduce the temperature. The water pressure should not be greater than 4kg · cm2.
The objective of the radiation temperature sensor must be kept clean. The measurement channel is blown with compressed air using a ventilation device. The compressed air must be filtered and sent to the ventilation pipe to prevent errors caused by moisture, dust, and contaminated lenses. Clean and wipe frequently.
The connecting cable is led out from the radiation temperature sensor, and the wire should be placed in a metal hose to maintain good electrical shielding and reliable mechanical protection. The image of the measured object seen from the eyepiece of the radiation thermometer must completely cover the thermopile to ensure that the thermopile fully receives the energy radiated by the measured object. If the image of the measured object is incorrect, it can be adjusted The distance between the radiation sensor and the measured object to enlarge the image.
The index of the secondary instrument of the radiation pyrometer and the radiation pyrometer must be the same, and the calibration should be performed regularly. After installation, regularly clean the lens dust, pay attention to whether there is mechanical vibration in the surrounding environment, and whether the probe is deviated. If there is an emergency, remove it and align it regularly to ensure that the furnace temperature is correctly reflected [1] .

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