Introduction - LUDLUM MODEL 2241-2 Technical Manual

Model 2241-2
1
Section
Ludlum Measurements, Inc.
Technical Manual

Introduction

T
he Model 2241-2 is a portable microprocessor-based digital scaler/
ratemeter designed for use with scintillation, Geiger-Mueller
(GM), and proportional type detectors to measure ionizing
radiation. Data is presented on a four-digit (six digits in the scaler
mode) Liquid Crystal Display (LCD) with moving decimal point. A three
position switch labeled ˝
operating mode for the instrument. A locking toggle switch labeled ˝
and 2˝ allows for quick change of operating parameters when changing
DET
out detectors.
Programmable display units (
either R/hr, Sv/h, cpm, or cps with multipliers of micro (µ) or milli (m) for
R/hr and Sv/h and kilo (k) for cpm or cps. The display units are auto-
ranging, enabling the readout to display a broad range of radiation levels.
The display also offers lower limit capability. For example, the display can be
set to show only values that are greater than or equal to1 µR/hr.
This instrument incorporates independent adjustable alarms for
and operating modes. The
SCALER
indicators. The first-level alarm is indicated by display of the word ˝
on the LCD. The second-level alarm is indicated by display of the word
˝ and by the emitting of a continuous audible tone. The
˝
ALARM
alarm condition will also display the word ˝
audible tone. Both audible alarms may be silenced (acknowledged) by
depressing the
RESET
Other features include Dead Time Correction (DTC) to compensate for
detector dead time; audible click-per-event with programmable 1, 10, 100,
and 1000 divide-by; LCD backlight with programmable
programmable fixed or variable response time; and count overflow visual
alarm, indicating that the counting circuitry is nearing the maximum
counting capability.
/
OFF RATEMETER
RATEMETER
RATEMETER
switch. All alarms are concurrent.
Page 1-1
Section 1
/ ˝ selects the desired
SCALER
mode only) are represented in
RATEMETER
mode has two alarm
˝ and produce the same
ALARM
ON
January 2016
1
DET
˝
ALERT
SCALER
time;