Ludlum Measurements 2241-3, Manual

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Model 2241-3 & 3i Technical Manual
Section 4
Ludlum Measurements, Inc. Page 4-4 January 2016
Note:
When making adjustments to the
HV
potentiometers, make
note of the following precautions: Use a Ludlum Model 500
Pulser or high-impedance voltmeter with a high-voltage probe
to measure the high voltage at the detector connector. If a
Ludlum Model 500 Pulser is not available, ensure that the
impedance of voltmeter used is 1000 megohms or greater.
HV1, HV2, HV3, HV4
: multi-turn potentiometers (approximately 20
revolutions) that vary the detector voltage from 400 to 2500 volts. The
maximum high-voltage output is adjusted by the
HV LIMIT
potentiometer
located on the internal main board.
Main Board Controls
Note:
To access the internal circuit boards, unlatch the latches at
each end of the Model 2241-3. Carefully separate the top
chassis from the bottom cover (referred to as a can). The can
has the audio speaker (unimorph) with a two-conductor cable
attached to the main board. The audio plug may be
disconnected during the internal control adjustments.
HV LIMIT (R027)
: A multi-turn potentiometer (approximately 20
revolutions) sets the maximum HV limit with the front-panel
HV
control
adjusted to the maximum clockwise position. It is adjustable from 1250 to
2500 Vdc.
VOLUME (R002)
: A multi-turn potentiometer (approximately 20
revolutions) varies the audible click-per-event and alarm audio. Adjust the
control to the maximum clockwise position for maximum volume. If the
VOLUME
control is adjusted to the maximum counterclockwise position, the
clicks-per-event, or the audible alarm(s), will not be audible when active.