Ludlum Measurements 23 User manual

MODEL 23 AND 23-1
ELECTRONIC PERSONAL DOSIMETER
August 2017

MODEL 23 AND 23-1
ELECTRONIC PERSONAL DOSIMETER
August 2017

ii

Ludlum Measurements, Inc. August 2017
STATEMENT OF WARRANTY
Ludlum Measurements, Inc. warrants the products covered in this manual to be free of
defects due to workmanship, material, and design for a period of twelve months from
the date of delivery. The calibration of a product is warranted to be within its
specified accuracy limits at the time of shipment. In the event of instrument failure,
notify Ludlum Measurements to determine if repair, recalibration, or replacement is
required.
This warranty excludes the replacement of photomultiplier tubes, G-M and
proportional tubes, and scintillation crystals which are broken due to excessive
physical abuse or used for purposes other than intended.
There are no warranties, express or implied, including without limitation any implied
warranty of merchantability or fitness, which extend beyond the description of the
face there of. If the product does not perform as warranted herein, purchaser’s sole
remedy shall be repair or replacement, at the option of Ludlum Measurements. In no
event will Ludlum Measurements be liable for damages, lost revenue, lost wages, or
any other incidental or consequential damages, arising from the purchase, use, or
inability to use product.
RETURN OF GOODS TO MANUFACTURER
If equipment needs to be returned to Ludlum Measurements, Inc. for repair or calibration, please
send to the address below. All shipments should include documentation containing return shipping
address, customer name, telephone number, description of service requested, and all other necessary
information. Your cooperation will expedite the return of your equipment.
LUDLUM MEASUREMENTS, INC.
ATTN: REPAIR DEPARTMENT
501 OAK STREET
SWEETWATER, TX 79556
800-622-0828 325-235-5494
FAX [phone]

Ludlum Measurements, Inc. August 2017

Ludlum Measurements, Inc. August 2017
Table of Contents
Introduction 1
Getting Started 2
Packing and Repacking 2-1
Battery Installation 2-1
Preparing the Instrument for Use 2-3
Operating the Instrument 2-3
Specifications 3
Description of Controls and Functions 4
Parts and Features 4-1
Display 4-2
Alarm 4-4
Safety Considerations 5
Environmental Conditions for Normal Use 5-1
Precautions 5-1
Cleaning Instructions 5-2
Recycling 6

Model23&23-1 TechnicalManual Section1
Ludlum Measurements, Inc. Page 1-1 August 2017
Introduction
he Model 23 EPDi is an electronic personal dosimeter, which
measures personal dose equivalent from external radiation sources. It
is ideal for the measurement and general monitoring of gamma and X-
ray radiation in medical and laboratory environments, as well as any
controlled or restricted area where personal radiation monitoring is required or
desired.
The Model 23-1 is identical to the Model 23, except that it measures in Sv/h
instead of R/hr.
The compact and lightweight body of the instrument (55.9 g {2 oz}) makes it
ideal for personal use. It can be compared to the size of an ink pen.
This instrument is sensitive to a wide range of energies from 35 keV to 3 MeV.
Dose, dose equivalent rate, and alarm values are easily seen on the four-digit
LCD screen. Each preset alarm threshold is displayed on the screen. When the
dose or dose rate reaches the preset alarm thresholds, the alarm activates.
Users who have multiple EPDi units, there is an optional reader/software kit
that can be used to quickly take data directly from the EPDi Dosimeter via
infrared communication to the user’s PC. The optional software also allows the
user to set or change alarm set points quickly.
Since the Model 23 has energy characteristics corresponding to 1 cm dose
equivalent, by placing it close to the body it is able to measure 1 cm dose
equivalent.
Notice!
The Model 23 Dosimeter may not measure pulsed radiation
accurately. Point the “body side” (noted on the dosimeter) or
display side towards the body or area to be measured. A dot next
to the gamma symbol on the instrument indicates the center
point of the unit.
Section
1
T

Model23&23-1 TechnicalManual Section2
Ludlum Measurements, Inc. Page 2-1 August 2017
Getting Started
Unpacking and Repacking
Remove the calibration certificate and place it in a secure location. Remove
the instrument 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 between instruments.
To return an instrument for repair or calibration, provide sufficient packing
material to prevent damage during shipment and appropriate labeling.
Every returned instrument must be accompanied by an Instrument Return
Form, which can be downloaded from the Ludlum website at
www.ludlums.com. Find the form by clicking the “Support” tab and
selecting “Repair and Calibration” from the drop-down menu. Then choose
the appropriate Repair and Calibration division where you will find a link to
the form.
Battery Installation
Replace the battery with the following procedure:
1. Press and hold the power switch (color: red) for approximately two
seconds until the Model 23 turns off.
2. Remove the battery door.
3. Extract the used battery using miniature pliers or something similar
and insert the new battery with the negative (-) side facing upward.
4. Replace the battery cover.
Section
2
Insert the battery with the
negative (-) side facing upward.

Model23 &23-1 TechnicalManual Section2
Ludlum Measurements, Inc. Page 2-2 August 2017
Caution:
Always turn off the Model 23 EPDi before replacing the
battery. Be sure to observe proper polarity when replacing the
battery. This product operates on the CR2450 battery (3.0 V)
only (Part # 21-8639). Only use the battery specified.
Note:
When a low-battery indicator appears, take readings within
one minute before replacing the battery. To save battery life,
the power saving mode should be used.
Warning:
Do not throw the dosimeter or batteries into a fire. This
could result in personal injury.

Model23&23-1 TechnicalManual Section2
Ludlum Measurements, Inc. Page 2-3 August 2017
Preparing the Instrument for Use
To start the Model 23 EPDi, press and hold the power switch (color: red)
for approximately two seconds.
When the measurement screen appears, the red LED lamp lights for one
second and one short beep sounds, indicating that the Model 23 is in the
measurement mode.
Operating the Instrument
Point the “body side” (display side) of the Model 23 towards your body and
insert the Model 23 into your pocket, securing it with the clip as shown
below.
Green LED lamp flashes.
ALM Batt: RED LED lamp flashes.
Replace the used battery with new one.
ALM E06: Red LED lamp flashes. Contact our
representative or agency.
ALM E11: Red LED lamp flahes.
Restart the Model 23 by following the procedure:
Press and hold the power switch for
approximately two seconds until the Model
23 turns off.
Pres and hold the power swith for
approximately two seconds until the Model
23 turns on.
To turn off the Model 23, press and
hold the power switch for
approximately two seconds.