Model 194 Series
User’s Manual
Section 4
Ludlum Measurements, Inc.
Page 4-1
October 2020
Operating Procedures
Note:
To open the battery lid, twist the slotted, knurled knob
counter-clockwise a quarter of a turn. To close, twist clockwise
a quarter of a turn.
Open the lid and install two "AA" size batteries. Note the (+) (-) marks
on the bottom of the battery holder. Match the battery polarity to these
marks.
Close the battery box lid.
Turn the instrument range selector switch to BAT. The BAT OK lamp
should illuminate. The display will also show the battery voltage. If the
lamp does not illuminate, recheck to be certain that the batteries have
proper polarity or replace batteries with fresh batteries.
Turn the instrument to the LO position. In a non-radiation area, it should
show background radiation levels, approximately 10 µrem/hr or 0.1
µSv/h.
If available, expose the instrument to a gamma check source, placing the
source in a reproducible position and distance relative to the detector.
If
the display over-ranges (showing a leftmost “1” and no other digits),
move the rotary switch to the HI position. Confirm that the instrument
responds and/or confirm that the check source reading is similar to the
last measurement of the check source.
If used, check the audio by switching the toggle switch AUD to the ON
position and verify operation. Optionally, check that backlight works by
switching the LAMP switch to the ON position.
Section
4
