Cube
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Revision 10 EN - 03/2021
12.2.3 Minimum and maximum energy input per measurement
The measured temperature rise in the absorber is decisive for an accurate and re-
producible measurement. Regardless of the starting temperature, we recommend an
energy input of approx. 300J per measurement.
Example: At 1kW laser power the recommended pulse length is 300ms.
E = P·t = 1000W · 0.3s = 300J
Fig. 12.4 on page28 shows information for selecting the energy permissible for a
measurement in conjunction with the absorber temperature.
25 35 45 55 65 75
Absorber temperature in°C
Permissible measuring energy in J
1000
3000
10
100
25°C Ambient temperature
Max. energy input
Min. energy input
The measuring range varies with the ambient
temperature. Especially when measuring small en-
ergies (< 200J), the absorber temperature should
be close to the ambient temperature in order to
achieve the highest possible measuring accuracy.
Fig. 12.4: Measuring range as a function of the absorber temperature
The minimum energy input indicates the lower limit values with which measurements
can still be performed within the specified accuracy. The maximum energy application
value specifies the limit at which the absorber reaches its permissible limit temperature.
The energy, e.g. for multiple measurements (series measurements) can be distributed
across the range shown in green.
If the absorber temperature is greater than 70°C, it won’t be possible to take any
further measurements. In this case, please wait until the absorber temperature has fallen
below 50°C (depending on the selected energy input). Please take the limit values from
Fig. 12.4 on page28 and Tab. 12.1 on page29.