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481
Operators Manual
Mode Button
To configure the MODE button to the opposite function without the RS-232 connection,
use the following procedure:
1. Turn the unit off.
2. Press the MODE button.
3. Turn the unit on while continuing to press the MODE button.
4. Release the MODE button when the display is in the "all elements on" condition.
5. Use the MODE button to toggle the instrument between the rate mode and the newly
selected freeze or integrate mode.
Integrate Mode
The Integrate mode is operational 30 seconds after the instrument is turned on and all of
the time after that. However the integrated exposure can only be displayed when the
MODE button has been configured as a toggle to display exposure rate/integrated
exposure. If the MODE button is pressed within the 30-second initialization period of the
unit, the display will read "0."
When integration starts, "0.0 R (0.00
exposure rate as required.
To reset the integration display, toggle the display from the Rate mode to the Integrate
mode. Keep the MODE button pressed for about 5 seconds. The display will clear, and
then read "0.0 R (0.00
Freeze Mode
When configured to select the Freeze mode, the MODE button acts as a toggle switch.
Press the button until FREEZE appears on the display. Operation in the Freeze mode
gives the user a constant reference of the highest exposure rate obtained from the time the
freeze function is initialized. The highest reading will appear as a single bar on the bar
graph. The current reading will continue to be displayed on the digital display and the bar
graph. If a measurement is obtained which exceeds the freeze bar reading, the freeze bar
will move to the higher measurement point. The operating range of the 481 remains
locked on the highest range attained during the Freeze mode so that the scale and the
multiplier remain the same.
For example, assume the scale units appear as 10, 20, 30, 40, 50, and the freeze bar is at
47 mR/h on the bar graph. If the 481 then measures a radiation field of 120 mR/h, the
scale units will change to 100, 200, 300, 400, 500, and the freeze bar will appear on the
graph at 120 mR/h. If the survey meter measurement goes below 100 mR/h, the units on
the scale will not change until the survey meter is taken out of the freeze mode. However,
the digital display will continue to show the current reading. The survey meter will
operate in the Freeze mode until the user toggles the MODE button to return to the
normal operating mode.
If a measurement is obtained which causes a range change higher than the
alarm set point range, the alarm will sound and continue to sound until the
freeze mode is disabled.
Self-Test
When the 481 survey meter is first turned on, it runs through a functional self-test
procedure. During this self-test, the firmware version of the unit is displayed, along with
the HI or LO chamber bias.
6
Shop for Fluke products online at:
Sv)" will be displayed. Toggle MODE to read
Sv)." Exposures are accumulated up to 999 R (9.99 Sv).
Note
MyFlukeStore
www.
1.877.766.5412
.com
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Table of Contents
Troubleshooting
