Analysis of five factors affecting temperature measurement by infrared thermometer
1. The relationship between the size of the temperature measurement target and the temperature measurement distance
At different distances, the effective diameter of the measurable target is different, so pay attention to the target distance when measuring small targets. The definition of the distance coefficient K of the infrared thermometer is: the ratio of the distance L of the measured target to the diameter D of the measured target, that is, K=L/D
2. Select the emissivity of the substance to be measured
Infrared thermometers are generally classified according to black bodies (emissivity ε = 1.00), but in fact, the emissivity of substances is less than 1.00. Therefore, when the true temperature of the target needs to be measured, the emissivity value must be set. The emissivity of a substance can be found in the "Data on the Emissivity of Objects in Radiation Thermometry".
3. Measurement of targets in strong light background
If the target being measured has bright background light (especially if it is directly exposed to sunlight or strong lamps), the accuracy of the measurement will be affected. Therefore, objects can be used to block the strong light directly hitting the target to eliminate background light interference.
4. Measurement of small goals
Aiming and focusing
Aiming: The small black dot in the eyepiece is the temperature measurement point. Use the black dot to aim at the target to be measured.
Focus adjustment: Move the objective lens back and forth until the target being measured is clearest. If the diameter of the target being measured is much larger than the small black dot, there is no need to adjust the focus. Please refer to the manual for specific methods of focusing.
When measuring smaller targets, for measurement accuracy
⑴The thermometer should be fixed on a tripod (optional accessory)
⑵ Accurate focusing is required, that is: use the small black dot in the eyepiece to align the target (the target should be filled with small black dots), adjust the lens back and forth, and shake your eyes slightly. If there is no relative movement between the small black dots being measured, adjust the focus. The focus has been completed
5. Use of maximum value, minimum value, average value and difference measurement function
⑴ Maximum value function ------- When measuring moving targets (such as steel plates and steel wire production), due to different surface conditions of the measured objects (such as iron nitrate, oxidized skin, etc. in some places of steel plates and steel wires in production) ), use this function to obtain more accurate measurements
⑵Minimum value function------especially suitable for measuring production processes such as flame heating targets
⑶Average function------especially suitable for measuring melting and boiling metal liquid
⑷Difference function-------Sometimes, you may be very concerned about how much the measured temperature T moves around a required temperature Tc (comparison temperature), so this function is very convenient. At this time, the instrument displays the difference: "T--Tc"·The meaning of maximum value, minimum value, average value and difference function
