Ludlum Measurements 2363 User manual

LUDLUM MODEL 2363
GAMMA-NEUTRON SURVEY METER
October 2015
Serial Number 220855 and Succeeding
Serial Numbers

LUDLUM MODEL 2363
GAMMA-NEUTRON SURVEY METER
October 2015
Serial Number 220855 and Succeeding
Serial Numbers

Ludlum Measurements, Inc. October 2015
Table of Contents
Introduction 1
Getting Started 2
Unpacking and Repacking 2-1
Battery Installation 2-1
Connecting a Detector to the Instrument 2-2
Battery Test 2-2
Operating the Instrument 2-3
Principle of Operation 2-3
Specifications 3
Description of Controls and Functions 4
Operator Controls 4-1
Internal Controls 4-2
Safety Considerations 5
Environmental Conditions for Normal Use 5-1
Cleaning Instructions and Precautions 5-1
Warning Markings and Symbols 5-2
Calibration and Maintenance 6
Calibration 6-1
Meter Calibration 6-1
Establishing an Operating Point 6-2
Maintenance 6-3
Recalibration 6-3
Batteries 6-4
RS-232 Interface 7
Communicating With the Model 2363 7-1
Commands 7-1
Read Commands 7-1
Set Commands 7-2
Command Descriptions 7-2

Model2363 TechnicalManual
Ludlum Measurements, Inc. October 2015
Model 2363 Interface Software 7-8
Functions 7-8
Main Screen 7-8
Auto Dump Data 7-10
Installation of the 2363 Interface Software 7-14
Removal of the Model 2363 Interface V2 7-14
Connecting to a Computer 7-14
Technical Theory of Operation 8
Troubleshooting 9
Recycling 10
Parts List 11
Model 2363 Gamma-Neutron Survey Meter 11-1
Main Board, Drawing 390 × 295 11-1
LED Board, Drawing 390 × 299 11-4
LCD Display Board, Drawing 390 × 170 11-4
Wiring Diagram, Drawing 390 × 290 11-4
Drawings and Diagrams 12

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Ludlum Measurements, Inc. Page 1-1 October 2015
Introduction
he Ludlum Model 2363 Gamma/Neutron Survey Meter is an easy-
to-use survey instrument capable of measuring both neutron and
gamma radiation levels simultaneously, incorporating both analog
and digital displays for maximum versatility. This instrument logs up
to 1000 data points in non-volatile memory and consists of sample number,
date/time stamp, ratemeter measurements (both neutron and gamma),
integrated dose, and location identifier (10 characters).
The Model 2363 contains an internal energy-compensated GM (Geiger-
Mueller) detector for gamma measurements and is normally sold with an
external Model 42-41 PRESCILA detector for use in neutron
measurements.
This instrument incorporates a long arc-length analog meter face, which
normally displays exposure rates from 0 to 10 mrem/hr. The instrument’s
digital display is a full six-digit liquid crystal display (LCD) with an arrow
symbol for counting overflow. The display is direct-driven for optimal
viewing and wide temperature response.
The Model 2363 range selector switch allows for multiplication ranges of
×0.1, ×1, ×10, and ×100, and a front-panel three-position toggle switch is
used for selecting display of neutron, gamma, or neutron + gamma levels.
Neutron and gamma pulses are allotted different audible tones for ease of
user discrimination. A two-position, momentary-action switch allows either
an analog meter reset or display of the current integrated dose rate on the
LCD.
The following alarms may be set via the RS-232 port:
Neutron Rate meter (0-9999.99 mrem/hr)
Gamma Rate meter (0-9999.99 mrem/hr)
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Neutron + Gamma Rate (0-9999.99 mrem/hr)
Neutron + Gamma Integrated Dose (0-99999.9 mrem)
These alarm points, when exceeded, will light the appropriate LED on the
front panel and activate the audio alarm. The alarms will continue until the
RESET toggle switch is depressed, or until the INTEGRATED DOSE is zeroed.
The Model 2363 communicates through an RS-232 port located on the
instrument can. The computer interface software is supplied on CD and
includes the following functions:
Downloading of header and logged data into an ASCII file
Setting and reading of instrument parameters
Setting of the CALIBRATION DUE DATE
Setting of the internal real-time clock/calendar

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Ludlum Measurements, Inc. Page 2-1 October 2015
Getting Started
Unpacking and Repacking
Remove the calibration certificate and place it in a secure location. Remove
the instrument and accessories (batteries, cable, etc.) and ensure that all of
the items listed on the packing list are in the carton. Check individual item
serial numbers and ensure calibration certificates match. The Model 2363
serial number is located on the front panel below the battery compartment.
Most Ludlum Measurements, Inc. detectors have a label on the base or body
of the detector for model and serial number identification.
Important!
If multiple shipments are received, ensure that the detectors
and instruments are not interchanged. Each instrument is
calibrated to specific detectors, and therefore not
interchangeable.
To return an instrument for repair or calibration, provide sufficient packing
material to prevent damage during shipment. Also provide appropriate
warning labels to ensure careful handling. Include detector(s) and related
cable(s) for calibration. Include brief information as to the reason for return,
as well as return shipping instructions:
- Return shipping address
- Customer name or contact
- Telephone number
- Description of service requested and all other necessary
information
Battery Installation
Ensure the Model 2363 range selector switch is in the ˝OFF˝position. Open
the battery lid by pushing down and turning the quarter-turn thumbscrew
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counterclockwise a quarter of a turn. Install two ˝D˝size batteries in the
compartment.
Note the (+) and (-) marks inside the battery door. Match the battery
polarity to these marks. Close the battery box lid and push down and turn
the quarter-turn thumb screw clockwise a quarter of a turn.
Note:
The center post of a flashlight battery is positive. The batteries
are placed in the battery compartment in opposite directions.
Connecting a Detector to the Instrument
Caution!
The detector operating voltage (HV) is supplied to the detector
via the detector input connector. A mild electric shock may
occur if you make contact with the center pin of the input
connector. Switch the Model 2363 to the OFF position before
connecting or disconnecting the cable or detector.
Connect oneend of a detector cable to the detector by firmly pushing the
connectors together while twisting clockwise a quarter of a turn. Repeat the
process in the same manner with the other end of the cable and in the
instrument.
Battery Test
The batteries should be checked each time the instrument is turned on.
Move the range selector switch to the BAT position. Verify that all three
alarm LEDs on the front panel turn on briefly. The LCD should go through
an initialization sequence displaying ˝88:8.8:8.8˝,then the current sample
number, and finally ˝0˝. Ensure that the meter needle deflects to the battery
check portion on the meter scale. If the meter does not respond, check to
see if the batteries have been correctly installed. Replace the batteries if
necessary.

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Operating the Instrument
Connect a detector to the instrument if you have not already done so.
Obtain a meter reading from a check source or calibrated source, if available.
Verify that the reading falls within the expected range. Remove the source. If
a radiation source is available, increase the meter count to exceed the alarm
threshold. Both the appropriate alarm lamp and audio alarm signal should
activate.
Depress the RESET toggle switch. The meter needle should drive to zero,
and the alarm circuit should de-energize, shutting off both visual and audible
alarms.
Proceed with use.
Principle of Operation
The detected neutron count rate is displayed by selecting the ˝N˝position on
the three-position ˝N/N+G/G˝toggle switch. Similarly, the sum of the
neutron and gamma count rate or the gamma count rate only is displayed by
selecting the appropriate ˝N+G˝or ˝G˝position. The digital display will show
a direct reading in dose rate. Multiply the reading on the analog rate meter by
the range multiplier position.
The ˝RESET˝ toggle switch position resets the meter pointer to zero and
deactivates any current alarm. The current integrated dose is displayed on the
digital meter dial by selecting the ˝INTEGRATED DOSE (ID)˝ position.
Note:
The accumulated integrated dose may be reset by pressing the
ID toggle switch while turning the instrument ON.