Models SRJ-7 and HRJ-7 Juno Survey Meters

IV.
OPERATION
SRJ-7
HRJ-7
A. TO MEASURE RAD1 AT1 ON I NTENSI TI ES:
1. TURN THE SELECTOR SWI TCH TO THE ON POSITION AND WAI T FIVE SECONDS FOR
THE ELECTROMETER TUBE FILAMENT TO WARM UP.
2. TURN THE SELECTOR SWITCH TO THE SET POSITION AND ADJUST THE ZERO
CONTROL UNTIL THE METER READS EXACTLY ZERO.
3. TURN THE SELECTOR SWITCH TO THE 'IXI" POSITION. IF THE METER READS
OFF SCALE, THE RADIATION PRESENT IS GREATER THAN 50 MR/HR IN THE
CASE OF THE SRJ-7 (STANDARO RANGE), AND THE SELECTOR SWITCH SHOULD
BE TURNED TO EITHER THE I1X1o1' OR
l'X1OO1r POSITION.
4. THE INSTRUMENT IS NOW READY FOR READING GAMMA RADIATION INTENSITY.
TO READ GAMMA AND BETA SI MULTANEOUSLY, SLIDE BACK THE ALUMINUM
SCREEN BY PULLING UP RIGHT HAND TAB "GI1 IN THE HANDLE.
BETA AND GAMMA SIMULTANEOUSLY,
ACETATE
TO READ ALPHA,
SLIDE BACK BOTH THE ALUMINUM AND
FI LTERS BY PULLING UP BOTH TABS IN THE HANOLE.
CAUT I ON
WITH BOTH FILTERS BACK, THE ALPHA SCREEN IS EXPOSED AND
CAN BE VERY EASILY DAMAGED. A VERY DELICATE TOUCH MAY
CAUSE IT TO RIP.
5; THESE INSTRUMENTS ARE CALf BRATED IN INTERNATIONAL ROENTGENS CORRECT-
ED TO STANDARD TEMPERATURE AND PRESSURE (32OF. AND 29.92 INCHES HG.)
WHEN USED AT 71 .6OF. (22°c)oAND 29.92 INCHES HG. (760 MM. HG.) FOR
TEMPERATURE OTHER THAN 71.6 F. AND PRESSURES OTHER THAN 29.921' HG.,
CORRECTION FACTOR
FOR
MUST BE APPLIED TO THE METER READING TO COMPENSATE
IONIZATION CHAMBER AIR DENSITY CHANGES.
CORRECTION FACTOR = 459.7 T°F. 29.92
531 .3 P. INCHES HG.
EXAMPLE: A
IS 25 MR/HR ON THE XIO RANGE = 250 MR/HR. THE AIR
TEMPERATURE IS 90 F. AND THE BAROMETRIC PRESSURE IS
29.131l HG.
459.7 t goo
--- 549.7
531 .3 531 .3
29*92 1 .027
29.13 -
RADIATION MEASUREMENT IS TAKEN AND THE METER READING
=I .035
CORRECTION FACTOR =1 .035 x 1.027 = 1 .063
CORRECTED READING = 250 MR/HR x i.063= 266 MR/HR.
A
THE EFFECTS OF AIR TEMPERATURE AND PRESSURE MUST BE TAKEN
INTO
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