Measurement preparations
To determine the surface temperature, the tool performs a contactless measurement of the natural infrared thermal radiation emitted by the object at which the tool is aimed. For optimum measuring results, the emissivity setting see Emissivity on the measuring tool must be checked before every measurement and adapted to the object being measured if necessary.
When the measuring tool is switched on for the first time, the high emissivity setting is activated by default. If the emissivity is changed, all the measured values will be erased. The emissivity setting remains saved when the measuring tool is switched off.
You can select from three different emissivity settings on the measuring tool. The following overview shows commonly used materials of a similar emissivity for each emissivity setting; note that these are examples and not an exhaustive list. Because the emissivity of a material is dependent on a variety of factors and is therefore variable, the details in the following overview serve only as guide values.
| High emissivity: Concrete (dry), brickwork (red, rough), sandstone (rough), marble, PVC flooring, plastic (PE, PP, PVC), rubber, anodised aluminium (matt), woodchip wallpaper, carpet, laminate, tiling (matt), parquet flooring (matt), paint (black, matt), radiator paint, wood, glass |
| Medium emissivity: Enamel, granite, cast iron, sand, fireclay |
| Low emissivity: Cork, porcelain (white), paint (slightly reflective) |
The following emissivity gradings are used:
- High emissivity grading: Approx. 0.95
- Medium emissivity grading: Approx. 0.85
- Low emissivity grading: Approx. 0.75
To change the emissivity setting, press the button Mode (9) repeatedly until the emissivity indicator (c) shows the required emissivity for the next measurement.
- Temperature measurements will only be correct if the emissivity setting matches the emissivity of the object. Otherwise, object temperatures could be shown to be hotter or colder than they are, which may present a danger if touched.
The infrared radiation of the measuring surface is determined during the contactless measurement of the surface temperature.
The laser point marks the approximate centre of the measuring surface. For an optimum measurement reading, position the measuring tool so that the laser beam meets the measuring surface perpendicularly to this point.
- Do not direct the laser beam at persons or animals and do not stare into the laser beam yourself (even from a distance).
Increasing the distance between the measuring tool and the object being measured increases the size of the measuring surface. At a distance of 1 m, the measuring surface is approx. 8.3 cm in size if the laser beam is perpendicular to a flat measuring surface.
At a surface temperature of −10 °C to +500 °C, the optimum measuring distance is between 0.75 m and 1.25 m. Below −10 °C, the optimum measuring distance is between 10 cm and 30 cm.
The displayed reading is the average value of all temperatures measured within the measuring surface.
- Stand back from very hot objects. There is a risk of burns.
- Do not hold the measuring tool directly against hot surfaces. The heat can damage the measuring tool.
Highly reflective or glossy surfaces (e.g. glossy tiles, stainless steel fronts or cooking pots) can affect the surface temperature measurement. If necessary, mask the area to be measured with a dark, matt adhesive tape that conducts heat well. Allow the tape to acclimatise briefly on the surface.
Measuring through transparent materials (e.g. glass or transparent plastics) is fundamentally not possible.
Consequently, the more suitable and stable the measuring conditions are, the more accurate and reliable the measurement readings are.
Infrared temperature measurement is impaired by smoke, steam or dusty air.
It is therefore important to ventilate the room prior to measuring, especially when the air is contaminated or steamy. For example, do not perform measurements in a bathroom immediately after the shower has been used.
Once ventilated, allow the room to reacclimatise a while until it returns to the usual temperature.