Fluke Biomedical 451B - Manual (Page 15)

Ion Chamber Survey Meter
Features
5
Features
The following sections describe the features of the Survey Meter.
Overrange Rate
If the instantaneous radiation rate measured by the Survey Meter exceeds
50 R/h (0.5 Sv/h), the 'R' in R/h or the 'Sv' in Sv/h displayed will blink to notify the
user that the radiation field exceeds the measuring capability of the Survey
Meter. Also, a potential error in the integrated radiation value may exist due to
this condition. The blinking will stop when the integrated value is cleared.
Low Batter Indicator
There are about 6 hours of operation remaining when the LOW BATTERY
indicator first becomes visible. When the LOW BATTERY indicator blinks, there
is less than 1 hour of operation remaining. These times are for two batteries
installed and from the first occurrences of these indications. If the Survey Meter
is turned off during a low battery condition, the batteries will recover somewhat,
but time of operation remaining will be less.
Audio Alarm
The audio alarm set points are set using the RS-232 COMM port connected to a
computer along with the associated software. The audio alarm set point is set in
increments of 1 % full scale. That is from 1 % to 100 % of full scale. The “A”
command in the menu allows access to the scale and percent set point. The
alarm will sound when readings reach or exceed the set point.
Integrate Mode
The Integrate Mode allows the Survey Meter to display the integrated exposure.
Exposures are accumulated up to 999 R (9.99 Sv).
Freeze Mode
The Freeze Mode will move a “bar” on the bar graph display to show the user the
peak value, and will lock on the maximum range. The Survey Meter will continue
to read and display current readings.
Auto-On Backlight
The Survey Meter is equipped with a backlight which automatically turns on when
ambient light drops below a predetermined level. The backlight will turn off when
the ambient light exceeds the predetermined level, which is factory set.