Factors Affecting Infrared Thermometers/Material Emissivity/Distance Factor Guidance

Factors Affecting Infrared Thermometers/Material Emissivity/Distance Factor Guidance

Factors Affecting Infrared Thermometers/Material Emissivity/Distance Factor Guidance
1. The relationship between the size of the temperature measurement target and the distance of the infrared thermometer
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 measured substance
Infrared thermometers/online thermometers are generally graded according to black bodies (emissivity ε=1.00), but in fact, the emissivity of substances is less than 1.00. Therefore, when the real temperature of the target needs to be measured, the emissivity value must be set. The emissivity of matter can be found from "Data on emissivity of objects in radiation thermometry".

3. Measurement of targets in strong light background
If the measured target has a bright background light (especially when it is directly illuminated by sunlight or strong lights), 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.

Fourth, the measurement of small targets
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

Focusing: The objective lens moves back and forth until the measured object is clear. If the diameter of the measured object is much larger than the small black dot, it is not necessary to adjust the focus. Please refer to the instruction manual for the specific method of focusing

When measuring smaller targets, for measurement accuracy
⑴ The thermometer should be fixed on the tripod (optional accessory)

⑵ Need to focus, that is: use the small black dots in the eyepiece to aim at the target (the target should be full of small black dots), adjust the lens back and forth, shake the eyes slightly, if there is no relative movement between the measured small black dots, then focus it's done

5. The use of the maximum value, minimum value, average value and difference measurement function
⑴Maximum value function-------For the measurement of moving targets (such as steel plate and steel wire production), due to the different surface conditions of the measured object (such as iron nitrate, oxidized skin, etc. ), use this function to get more accurate measurement

⑵Minimum value function-------especially suitable for the occasion of measuring the production process of the target of flame heating

⑶ Average value function-------especially suitable for measuring molten and boiling metal liquid

⑷ Difference 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 Value: meaning of "T--Tc" maximum value, minimum value, average value, difference function

[1], Instantaneous value: the current temperature value of the measured target, also known as real-time value

[2], maximum value (MAX): the highest temperature value of the measured target within the time interval △t (the time interval △t can be modified)

[3] Minimum value (MIN): the lowest temperature value of the measured target within the time interval △t (the time interval △t can be modified)

[4], Average value (AVG): The average temperature value of the measured target within the time interval △t (the time interval △t can be modified). Maximum value, minimum value, and average value (as shown in the thick line of the temperature measurement curve in the figure below). The comparison or calculation is carried out again every time Δt.

[5], difference (DIF): the difference obtained by subtracting the comparison temperature value from the instantaneous value of the measured target (the comparison temperature value can be modified), it can be positive or negative

temperature output function
(1) Digital signal output - RS232, RS485, temperature signal remote transmission
 

(2) Analog signal output - 0~5V, 1~5V, 0~10V, 0/4~20mA, which can be added to the closed-loop control.
 

(3) High alarm, low alarm - In the production process, it is required to control the temperature within a certain range, and the high and low alarm values can be set. High alarm: When the high alarm setting is turned on, when the temperature is higher than the high alarm value, the corresponding LED light will flash, the buzzer will sound, and the AH normally open relay will be connected. 
Low alarm: When the low alarm setting is turned on, when the temperature is lower than the low alarm value, the corresponding LED light will flash, the buzzer will sound, and the AL normally open relay will be connected.
Online thermometer, infrared thermometer, digital noise meter, temperature and humidity meter, soil non-nuclear density meter, digital illuminance meter, digital anemometer