Models SRJ-7 and HRJ-7 Juno Survey Meters

3. Turn the Selector Switch to the "x1" position.
If the mefer reads
off scale the radiation present is greater than 50 m/hr and the Se-
lector Switch should be turned to either the "x10" or "~100" position.
4.
The instrument is now ready for reading gamma radiation intensity.
To read gamma and beta simultaneously, slide back the aluminum
screen by pulling up right hand tab "G" in the handle.
To read al-
pha, beta and gamma simultaneously, slide back both the aluminum and
acetate filters by pulling up both tabs in the handle.
CAUTION
WITH BOTH FILTERS BACK, TRE ALPHA SCREEN CAN BE VERY
EASILY DAMAGED. A VERY DELICATE TOUCH MAY CAUSE IT
TO RIP.
V. CALIBRATION
A. Internal Adjustments
Calibration.
for each range.
There are three internal calibration controls; one
These controls are accessible, through holes in the
top of the case, by removing the cover plugs labeled xl, x10, and xl00.
These controls should not be changed unless there are calibrated radium
or C060 sources available for accurate recalibration.
The proper proce-
dure for calibrating the Model SRJ-6 (Standard Range) is as follows:
1.
2.
Turn the instrument ON and allow several minutes warm-up.
Turn to the SET position and zero the meter with the Zero Control.
3.
Place the instrument in a radiation field of 15 MR/HR
switch to the xl position.
and turn the
4.
Remove the cover plug labled xl on the top of the case and adjust
5.
the internal control until the meter reads 15 MR/HR.
Place the instrument in a radiation field of 45 MR/HR
and check the
meter reading. Readjust the calibration control if necessary. Ac-
curacy of the calibration on all three ranges should be such that
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