ELECTRONIC PERSONAL DOSEMETER HANDBOOK
EPD/HB/40521/000
OPERATING INSTRUCTIONS
ISSUE 5
Thermo
Page
37
Note
: To avoid false alarms due to counting statistics it is recommended that the
Hp(0.07)/h dose rate alarm is not set to less than 100
µ
Sv/h
Example 1
st
Hp(10)/h dose rate on
alarm threshold display set at a
default value of 500
µ
Sv/h:
'On' and 'Off' alarm thresholds allow hysteresis for dose rate alarms, see section
3.5.1. If hysteresis is not to be used the ‘On’ and ‘Off’ thresholds should be set to
the same value.
Changing the Dose Rate Alarm Thresholds (ON and OFF)
:
To change the 1
st
H p(10)/h dose
rate on alarm threshold, for
example, select the above display
and double-press the button. The
display will change to the following
and the digits will flash:
Alarm Set Limits: 10
µ
Sv/h to 1Sv/h
Pressing the button will increase the alarm threshold in the following steps:
10
µ
Sv/h, 50
µ
Sv/h, 100
µ
Sv/h, 500
µ
Sv/h, 1mSv/h, 5mSv/h, 10mSv/h, 50mSv/h,
100mSv/h, 500mSv/h, 1.0Sv/h. When the required threshold is reached double-
pressing the button to confirm the value and the flashing display will stop.
If you start to change the threshold and change your mind this option can be
aborted, as follows:
Short-press the button until the
following is displayed (letters
flashing). Double-press the button
to confirm that you wish to escape
and return to the previous alarm
threshold.
If the ‘ESC’ screen is displayed and the button is not pressed, after default time-
out the display will return to dose alarm threshold that was being set-up. Again, if
the button is not pressed, the display will return to the top level default screen
after a further time out period.
