Ludlum Measurements 12, Техническое руководство

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Model 12 Technical Manual
Section 1
Ludlum Measurements, Inc. Page 1-1 July 2017
Introduction
he Model 12 is a portable survey meter with four linear ranges used
in combination with exposure rate or
CPM
meter dials. The
instrument features a regulated high-voltage power supply,
unimorph speaker with audio
ON
-
OFF
capability, fast-slow meter
response, meter reset button, and a six-position switch for selecting battery
check or range multiples of ×1, ×10, ×100, and ×1000. Each range
multiplier has its own calibration potentiometer. The unit body and meter
housing are made of cast aluminum, and the can is 0.23 cm (0.09 in.) thick
aluminum.
The audio provides a brief “click” for every radiation event detected. It also
provides a steady tone to warn the user of a low-battery condition. This low
battery warning overrides the position of the
AUD ON
-
OFF
switch.
With an adjustable detector voltage of 400-2500 volts and adjustable
discriminator of 1-100 millivolts, this unit can be operated with most
proportional, scintillation, or GM detectors. Scintillation detectors will
require voltage divider circuit resistance in excess of 50 megohms.
The unit is operated with two ˝
D
˝ cell batteries for operation -20 to 50 °C (-4
to 122 °F). For instrument operation below 0 °C (32 °F), either very fresh
alkaline or rechargeable NiCd batteries should be used.
Section
1
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