La Crosse Technology IR 101 instruction manual Back light, Measurement inaccuracies

5.Back light

The LCD back light is constantly switched ON while the operating button is pressed. When the operating button is released, the backlight will be ON for approximately 4 seconds before automatically switching off 8 seconds after the last measurement.

6.Measurement inaccuracies

The following points should be observed in order to avoid measurement errors:

a.It must be ensured that the object to be measured completely fills the Infrared Thermometer monitoring area. Errors can occur when measuring small objects, as the unit also monitors the temperature of the surroundings as well as the object to be measured.

b.The principle of measurement requires the ambient temperature to be determined. This takes place at one-minute intervals or each time the unit is switched on. Changes in the ambient temperature, which can occur when the user holds the unit in their hand, are not monitored within this time period and therefore neither of them is taken into account when determining the indicated temperature. A gradual warming of the unit (the lens) between ambient temperature measurements can, for example, lead to the indicated temperature slowly falling.

c.If the emission factor for the object does not correspond to the preset value of 0.95, the temperature will not be calculated correctly. Most surfaces have an emission factor in the range of 0.8 to 0.98. In general, the darker and more matte the surface is, the larger their emissions factor. If the factor is greater the 0.95, the temperature indicated will be greater than the actual temperature of the object being measured. If the factor is less then 0.9, the temperature indicated will be less than the surface temperature. Polished metals have a very low emission factor and are therefore not suitable for measuring with an infrared thermometer. On the other hand, affixing adhesive tape to or painting the surface will increase the emission factor and reduce the inaccuracy of the measurement.

d.It is not possible to take measurements through transparent materials (glass, plexiglas, etc.).

e.It is not possible to measure air temperatures.

f.Measurement errors can occur due to air contaminated with dust, steam, smoke, etc.

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