Before you begin taking the measurement, there are a few things that should be noted. The GTC models include features such as a variety of different options for the colour scale, depending on your preference. These options include intuitive flame-like colours, the rainbow colour scale, a psychological colour scheme or plain greyscale.

For smaller temperature differences, it is recommended to use a high-contrast colour palette (e.g. the rainbow scale), whilst larger variations in temperature make a low-contrast scale (e.g. flame colours) the more intuitive option.

In order to configure the thermal image so that it is rich in contrast and consequently provides conclusive information, the scale needs to be adapted under certain circumstances. To this end, our thermal imaging cameras offer a practical lock function that allows you to optimise this scale quickly and easily.

For instance, if you wish to carry out a thermographic analysis of a window under which a radiator is located, the presence of this radiator will alter your entire thermal image, in the sense that the temperatures around the window will be less clearly differentiated. One possible way to avoid this is to approach the window with the thermal imaging camera to the point where the heating system is no longer visible in the thermal image field. Then lock the colour scale by pressing the top right button – and you can now obtain a detailed image even from far away. Alternatively, this can be implemented in manual mode.

Wherever possible, you should measure objects only when they are dry, since rain and other forms of precipitation can influence the surface temperature. Similarly, measurement of objects that have been significantly exposed to sunlight should also be avoided, since the surface can be considerably warmed as a result of this. If you plan to take thermal images outside, we also recommend that you do this in the early hours of the morning. High humidity and wind can also have a negative impact on the accuracy of the measured values and should therefore be avoided.

We also advise against taking measurements in the direct proximity of heat sources (e.g. ovens). It may be possible, however, to shield these off from the rest of the measurement and thus reduce their influence. In most cases where thermal imaging of buildings is required, autumn and winter tend to be the ideal seasons for taking measurements. At these times of year, the temperature difference between the interior and the exterior is great enough for problem areas to be located effectively (recommended minimum temperature difference: 10 °C).

If you intend to determine a precise value in degrees Celsius (°C), you should account for the emissivity and the reflected temperature in every case. This way, you can prevent measured values from being rendered incorrectly as a result of strong reflections.

You can determine the emissivity from the preset materials in the tool or estimate it on the basis of the surface quality. In order to determine the reflected temperature, you should first check whether the reflection in question is direct or indirect. Direct reflections frequently occur on smooth surfaces and can be recognised as a reflection in the thermal image (e.g. on a glass pane). In such cases, the temperature value of the object being reflected can be used as the reflected temperature. In contrast, indirect reflections mainly occur on rough surfaces (e.g. plaster). In this case, determine the average temperature in front of the object to be measured and set this as the reflected temperature.

For excessively reflective surfaces, such as bare metal, we recommend the use of matt black adhesive strips or special sprays. If you apply these to the reflective object, you can take its temperature after a short waiting period and reliably determine this on the basis of a high emissivity. The influence of the reflection of one's own body heat can also be minimised by measuring at a slightly slanted angle.

Alternatively, using a temperature probe (type K) with the GIS 1000 C infrared thermometer can help. Using the temperature probe avoids any reflection and the temperature is directly measured by coming into contact with the object.

In order to guarantee thermal images of high quality, you should keep to a minimum distance of 30 cm when taking a measurement. A two-step procedure has proven to be effective in this regard.

For instance, if you are examining a wall for insulation problems, a preliminary inspection from a further distance will provide a good initial overview. A second image capture – this time at a closer range – will then provide more detailed information and be significantly more reliable, since any distance-related errors can then be ruled out at this stage. Because the measuring distance has such great influence on the quality of the measurement, this should generally be taken within the closest possible range to the object.