Uni-Probe LB 490
BERTHOLD TECHNOLOGIES GmbH & Co. KG
3 – 335
Volume 3 Menu Structure
3
2.39 PLATEAU
1 MEASURE PLATEAU
Select MEASURE PLATEAU to start the plateau measurement.
This function also allows you to edit the parameters for recording
the plateau. How to record a plateau is described in detail on
page 3–367.
2 SHOW PLATEAU PTS
Shows the value pairs of the data points that have been recorded
with
MEASURE PLATEAU. This function also allows you to edit the
parameters for recording the plateau.
Explanations A plateau measurement checks the function of the detector. The
result of a plateau measurement is presented in a table. This table
includes the high voltage and count rate values. The values are
divided into HV steps.
Radiation conditions must be constant while recording the plateau!
Draw a curve with these values to identify the plateau.
Figure 2-5 Plateau measurement
The plateau is the flat section of the curve and it is typically approx.
200V long. The crystal-multiplier assembly or the complete detec-
tor has to be replaced if
• the plateau is shorter than 50V
• the count rate changes by more than 5% per 100 Volt high
voltage
For further information on plateau measurement and on the crys-
tal-multiplier assembly please refer to section 5.1.
100
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I/s
HIGH VOLTAGE (V)
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Plateau
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