Guidance on common problems with infrared thermometers/fixed thermometers
Common problems with infrared thermometers/fixed thermometers? Guidance question: The relationship between the size of the temperature measurement target and the temperature measurement distance (concept of optical resolution)?
Answer: The effective diameter D of measurable targets varies at different distances, so attention should be paid to the target distance when measuring small targets. The distance coefficient K of an infrared thermometer is defined as the ratio of the distance L of the measured target to the diameter D of the measured target, i.e. K=L/D
Q: How to choose the emissivity of the measured substance when using a thermometer?
Answer: Infrared thermometers are generally divided by blackbody (emissivity ε=1.00), but in reality, the emissivity of substances is less than 1.00. So when measuring the true temperature of the target, the emissivity value should be set. The material emissivity can be obtained from the data on the emissivity of objects in radiation thermometry.
Question: How to measure targets in a strong light background of an object?
Answer: During the use of a thermometer, if the measured target has bright background light (especially when exposed to sunlight or strong light), the accuracy of the measurement will be affected. Therefore, objects can be used to block the strong light of the direct target to eliminate background light interference.
Q: How does a thermometer measure small targets?
Answer: Aiming and Focusing Aiming: The small black dot in the eyepiece is the temperature measurement point. Aim the black dot at the measured target for focusing: The objective moves back and forth until the measured target is clear. If the diameter of the measured target is much larger than the small black dot, accurate focusing may not be necessary. For the specific focusing method, please refer to the manual. When measuring small targets, focusing is required for the accuracy of measurement, that is, use the small black spots in the eyepiece to aim at the target (the target should be full of small black spots), adjust the lens back and forth, and shake the eyes slightly. If there is no relative movement between the small black dots measured, the focusing of the thermometer is completed.
Q: How to use the function of measuring the difference between the average size of an infrared thermometer correctly?
Answer: High value function - When measuring moving targets (such as steel plates and steel wires), due to different surface conditions of the object being measured (such as steel plates and steel wires with iron nitrate and oxidized skin in certain areas), this function can be used to obtain more accurate measurements.
Small value function - especially suitable for measuring targets in flame heating processes.
Average function - particularly suitable for measuring metal liquids with melting boiling
Differential function - You may be concerned about how much the measured temperature T fluctuates around a required temperature Tc (comparison temperature), which makes this function very convenient. At this point, the instrument displays the difference as "T - Tc"
