Exploranium GR-135, System Manual, Page: 74 / 80

SAIC Exploranium – GR-135 System Manual page: 74
APPENDIX H – WIPE TEST (OPTIONAL)
If requested by the user, before the GR135 is shipped, a
special capability is enabled that permits a WIPE TEST function.
This function permits the GR135 to provide an semi-automatic
measure of removable contamination. This function only
operates in the AUTO mode.
In SETUP/IDENTIFY/DETECTOR a new parameter WIPE TH
may be set – the parameter is set 1-10 in SD units with a default
of 3.
Function is as follows:
1. If the portal system alarms then the GR135 is used to find the location of the maximum radiation
on the side of the vehicle
2.
The user normally then carries out IDENTIFY to determine the isotopic content of the radiation as
described earlier in the manual
3.
Once located and identified, then the vehicle must be tested for REMOVABLE CONTAMINATION.
The user takes a standard WIPE TEST sample cloth and carefully wipes a 10cm
2
area around the
area of the vehicle side where the maximum radiation has been detected. This sample material
is then placed in a plastic bag.
4.
Press ENTER until the display shows the SEARCH mode. The bottom of the display shows
“UP=WIPE ENTER=IDENTIFY”
5.
Click UP (for WIPE). The display shows the message “BACKGROUND NEEDED – MOVE
AWAY FROM VEHICLE THEN PRESS ENTER”
6.
Move the GR135 at least 10ft away from any vehicle in the SEARCH mode, keep the test sample
bag at least 3 ft away from the GR135 and check that the local Dose Rate where the test will be
carried out is below
10uR/h
–- then press ENTER. Higher background will negatively affect
sensitivity of the measurement.
a. If the local Background is above 20uR/h the display will show the message “DOSE RATE
TOO HIGH – MOVE TO LOWER BACKGROUND”. The user must find an area where
the background is lower, or use a shielded compartment to facilitate the measurement.
7.
The display will start the IDENTIFY screen for the preset sample period to get a background
sample
8.
The display then shows “PLACE WIPE SAMPLE AT DETECTOR FACE THEN PRESS ENTER”
9.
Place the plastic bag contain the sample as indicated and press ENTER
10.
The display will start the IDENTIFY screen for the preset sample period
11.
At the end of this time period the system computes the Contamination Level and compares it to a
preset threshold.
12.
If NO CONTAMINATION is detected - at the end of sample the display will show “WIPE TEST
CONTAMINATION IS BELOW ALARM LEVEL”
IDENTIFY
NON ID THR
WIPE TH
PILEUP
AUTO
DETECTOR
ON
30
25
3
PEAK LIMIT