LUDLUM 70 User guide

LUDLUM MODEL 70
SPECTROMETRIC PERSONAL RADIATION
DETECTOR/IDENTIFIER
May 2021

Model 70
Spectrometric Personal Radiation Detector/Identifier
SYSTEM MANUAL
May 2021

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]

Table of Contents
1. GENERAL SYSTEM DESCRIPTION...............................................................................................................1
1.1 HARDWARE VERSIONS.................................................................................................................1
2. SYSTEM DESCRIPTION & FEATURES..........................................................................................................2
2.1 OPERATIONAL FUNCTIONS.........................................................................................................2
2.2 SYSTEM FEATURES........................................................................................................................2
3. QUICK START.............................................................................................................................................5
4. DETAILED OPERATION GUIDE ...................................................................................................................6
4.1 CONTROL BUTTONS......................................................................................................................6
4.2 DISPLAY CONTRAST......................................................................................................................7
4.3 EXTERNAL AUDIO..........................................................................................................................7
4.4 SEARCH+DOSE, Screen 1................................................................................................................7
4.5 IDENTIFY, Screen 2..........................................................................................................................9
4.6 SETTINGS, Screen 3........................................................................................................................12
5.0 SPECIFICATIONS ....................................................................................................................................16
APPENDIX A: GalaXrayWiz SOFTWARE, Graphic User Interface.................................................................18
APPENDIX B: NUCLIDE LIBRARIES ...............................................................................................................27
APPENDIX C: MANUAL CHANGES ...............................................................................................................28

Spectrometric Personal Radiation Detector (SPRD) –
Radioisotope Identifier (RIID)

Model 70 System Manual
Ludlum Measurements Inc. 1 May 2021
1. GENERAL SYSTEM DESCRIPTION
The Model 70 Spectrometric Personal Radiation Detector (SPRD) represents a major
breakthrough in the field of radiation monitoring, offering the user not only the ability to search
for and locate radioactive material, but also to identify the radioactive nuclides present. This
capability in a fully portable hand-held unit that will permit its use in a wide variety of
applications including:
- Hazard identification and risk assessment
- Inspection of incoming and outgoing material for radioactive contamination
- Inspection of radioactive gauges for leaks
- Search of waste sites for radioactive material
- Employee exposure rate and dose monitoring
- Radioactive source monitoring
- Government inspection for material compliance
- Identification of unknown radioactive material
- Regulatory control of radioactive material
- Classification of radioactive material for a wide variety of users
- Detection of illicit trafficking of nuclear materials
- Monitoring of the radiation situation at nuclear facilities
1.1 HARDWARE VERSIONS
70/1 –the basic Model 70 is a single detector system utilizing a CZT (Cadmium Zinc Telluride)
hemispherical detector for high-energy resolution and sensitivity
70/2 –the Model 70 with single CZT detector and Li6-based neutron detector
70/3–the advanced model with large 1.6 cm3CZT
70/4 –the advanced model with large 1.6 cm3CZT and Li6-based neutron detector

Model 70 System Manual
Ludlum Measurements Inc. 2 May 2021
2. SYSTEM DESCRIPTION & FEATURES
This manual fully describes the system functionality of the unit along with the associated PC
software program.
2.1 OPERATIONAL FUNCTIONS
The Model 70 can be operated in two primary radiation monitoring functions.
1. Search + Dose Mode –In this mode, the Model 70 acts as a radiation search/survey
meter displaying the current dose rate and count rate. A “chart-record” of the last 60
data points is displayed on the screen during the search. This mode is typically used to
search for radioactive material or to carry out total-count search. This mode also
displays the current dose rate up to user selection in Sv/h or in Rem/hr, as well as
cumulated radiation dose from the time the mode was engaged. The dose meter is used
to determine the relative hazard level and to assess handling requirements of a
radioactive material.
The yellow line represents 20-second dose rate running average.
Visual, Audio, and Vibration mode alarms will be activated if the dose rate exceeds the
defined threshold.
2. Identify Mode –(Nuclide Identification) In this mode, the Model 70 accumulates
spectral data from a sample and analyzes the spectrum in terms of emitted energy and
net count contribution. The nuclides responsible for producing the spectrum are
identified by comparison to a nuclide library and presented in tabular form on the
screen. This essential information can then be used to determine the radiation risk to
the individual.
2.2 SYSTEM FEATURES
Instrument Body –The instrument body consists of a single, rugged, plastic housing. The
housing has an option for the instrument to be mounted on a belt for ease of carrying during a
constant dose monitoring situation. In addition, included is a carrying case to carry and protect
the unit when not in use.
Detector
1. CZT –A 0.5 cm3or 1.6 cm3(optional) CdZnTe semiconductor hemispherical crystal is
used for the detection of gamma radiation and provides a high-resolution signal for the
systems nuclide ID capability. CZT is a specialized detector with a resolution several
times better than that of widely used inorganic scintillators (i.e Sodium-Iodide, Cesium-

Model 70 System Manual
Ludlum Measurements Inc. 3 May 2021
Iodide) thus allowing discrimination of gamma peaks that are impossible to see on a
scintillation-based detector. The detector is strategically mounted on the front of the
assembly and optionally the center is indicated by the dot on the outside of the housing.
2. Li6 –based neutron detector, optional.
Operational Buttons –The Model 70 has three operating control buttons. The buttons are all
enclosed in one easy-to-clean plastic membrane. All system functions are controlled by these
buttons that permit easy instrument handling.
The buttons are specially arranged for use and to toggle between the menus and operational
options with three actions –START, ENTER/SAVE, and CANCEL/SET. The buttons and use of
menu-driven functions make the Model 70 very easy to operate and avoid the necessity of
“memorizing” complex sequences of action.

Model 70 System Manual
Ludlum Measurements Inc. 4 May 2021
Display –A color LCD is used for the Model 70 to permit a full range of alphanumeric and
graphic display capabilities. The display contrast may also be manually adjusted depending on
ambient light conditions. The unit also incorporates automatic temperature compensation to
maintain correct contrast even when the external temperature substantially changes.
Indicators –The Model 70 has two LED indicators. One, a green LED, indicates the unit is
operating. The second, a red/green LED, serves as an addition to the screen to indicate a
warning or an alarm condition.
Batteries –An internal, lithium-ion, rechargeable battery is shipped fully charged.
Battery Charger –In the Model 70, the battery charger is external. To get the battery fully
charged requires 4 to 5 hours.
about 5 hours.
System Support Software, Graphic User Interface (GUI) –Support software, GUI GalaxrayWiz,
is provided with the Model 70 on USB flash memory. This is a Windows-based program and
operates in Windows 7 and higher. The program is described in Appendix B and provides data
downloading, spectrum display and spectrum analysis, and various other features.
Power jack
USB
Earphone jack

Model 70 System Manual
Ludlum Measurements Inc. 5 May 2021
Vinyl Carrying Case –The system is supplied with a vinyl carrying case. An easy-open flap allows
access to the instrument while providing additional mechanical and weather protection.
Manual –This user manual is supplied with the instrument on USB flash memory.
3. QUICK START
This section offers a simplified guide to system operation; a more complete description is
available in Section 4.
Button Operations - the three buttons on the instrument face are the only controls for the unit.
Basic actions are START, CANCEL/SET, and ENTER/SAVE. Some operations require a short
activation where SHORT = less than 0.5 seconds or LONG = 3 seconds.
Power ON/OFF –Press down the ENTER/SAVE button for at least three seconds, and the unit
will power ON. After successful completion of a power-on self test and a few seconds, the unit
will automatically go into the Search + Dose mode. When the unit is powered on, the green

Model 70 System Manual
Ludlum Measurements Inc. 6 May 2021
power indicator LED will be illuminated. To power off the unit at any time and in any screen,
press and hold the ENTER button for more than 3 seconds.
USB connector –The USB connector is used to transfer recorded dose time chart, gamma-
spectra, and other data to and from a PC.
Search + Dose –After power ON, the “Search + Dose”is activated automatically. The system
display will show the current dose rate in Sieverts per hour (Sv/hr) or Rem/hr, usually in
relevant radiation level scale like nano Sievert (nSv/hr), or micro Sievert (µSv/hr), µRem/hr, and
count rate in counts per second (cps) while the internal “audio meter” will give an audio
response.
Identify –by pressing the ENTER button shortly, the unit displays the second main screen with
nuclide ID function for a gamma-spectrum acquisition for a pre-set duration. As the spectrum is
being accumulated, it is displayed on the screen so the user can observe the spectrum as time
progresses. At the end of accumulation period, Nuclide Identification is displayed on the
screen. The accumulated spectrum is then automatically stored with system name composed of
the date and time the spectrum was collected. All spectrums are stored for later analysis when
output to a PC.
To switch between the Search/Dose screen and the Identify screen at any time, press the
ENTER button shortly.
4. DETAILED OPERATION GUIDE
This section offers a detailed guide to system operation.
4.1 CONTROL BUTTONS
The Model 70 is equipped with three control buttons on the front face. These are the only
controls on the instrument.
START and CANCEL/SET –is used to scroll through menus displayed on the screen.
ENTER/SAVE - is used to activate the selection highlighted on the display. Some operations
require a short press and some require a long press.
Short = less than 0.5 seconds
Long = 3 seconds
Power OFF –To power the unit OFF, press the ENTER button and hold for approximately three
seconds. The display shows the seconds counting down: “3, 2, 1.”After this the message,

Model 70 System Manual
Ludlum Measurements Inc. 7 May 2021
Please release the button appears, and upon doing that, the power will be OFF. At any time
during the countdown, releasing the ENTER button will cancel the power OFF.
4.2 DISPLAY CONTRAST
The contrast is automatically adjusted by temperature compensation using an internal
temperature sensor.
4.3 EXTERNAL AUDIO
On the lower left side of the unit is a special connector (external audio) or earphone jack
(shown on page 4). Users with the optional external earphone can plug it into this socket. When
this is done, the internal audio is silenced and the audio tones are only audible through the
earphone. This silencing of the unit’s audio is especially useful in covert scanning or when the
operator does not wish to alarm anyone with sudden audio tone increases.
4.4 SEARCH+DOSE, Screen 1
Search Mode
The search and dose mode is used to search out radioactive sources along with monitoring the
radiation dose to which the unit is exposed.

Model 70 System Manual
Ludlum Measurements Inc. 8 May 2021
The top graph in the prior photo shows the graphical profile of the dose rate along with the
current date/time. The second window displays the current dose rate as detected by the
instrument. Using these two windows the user can easily identify the direction to the source as
necessary before the spectrum is acquired and a source ID is performed.
The last box shows the cumulated dose over the time period selected by the user in the setting
screen as described in the parameter setting screen section below.
The cumulated dose bar is in logarithmic scale since cumulated dose threshold is relatively large
in comparison with dose rate. The dose profile, dose rate, and cumulated dose will always be
calculated and displayed when the unit is in the Search + Dose screen. The user can simply
watch the current dose rate and the cumulative dose from Screen 1 without recording.
The neutron detection is shown as N/C, which is neutron counts in a one-minute running
average.
Saving Dose
The instrument can save up to 24 hours of dose rate records.
To begin recording the dose time profile from Screen 1, the user can press the START (Up
arrow) button. The dose rate time profile is recorded into memory for the pre-set time as
selected in the settings window (default is 60 sec). The red circle (recording) will appear in the
right upper corner of the display with recording time remaining in the format “hh:mm:ss.”
1. The user can stop recording at any time by pressing CANCEL/SET (Down arrow). After
stopping recording, the following tips will appear at the bottom of the screen: Resume,
Save, and Cancel. The tips are assigned over each of three buttons accordingly for
further actions:
Pressing ENTER/SAVE will save the current dose recording (the unit
will automatically assign the file name).
Save Dose - ENTER/Save
Cancel Save - Cancel/Set
Resume Dose - Start

Model 70 System Manual
Ludlum Measurements Inc. 9 May 2021
Pressing CANCEL will cancel the current dose recording and clear all
data associated with this Dose recording (completely cancel the
recording).
Pressing START will resume recording of the Dose.
Upon the Model 70 completing the dose recording by reaching the preset time as determined
in the settings screen, the dose rate profile will be automatically saved. The unit automatically
assigns the dose rate file name in the same way as spectra. The dose profiles can be
downloaded to a PC using GalaXrayWiz GUI software.
2. After saving the dose profile, the following tips appear on the display:
Start, Spectra Acq, Settings
Press Start to start over the dose recording until pre-set time or next
interruption.
Press Spectra Acq to get to Nuclide ID Screen 2.
Press Settings to change the instrument settings.
To get back to original Screen 1 Search + Dose, the user has to get to
Screen 2 Nuclide ID, and then by pressing ENTER/SAVE, the
instrument will get back to Screen 1
3. The user can save as many dose recordings as the instrument memory allows by
consequently pressing START/STOP and ENTER/SAVE.
4.5 IDENTIFY, Screen 2
Spectrum/Identify Mode
The Spectrum/Identify mode is used to display the spectrum of the radiation isotope being
monitored and to use the internal library to help identify the isotope.
Identified nuclides are given the categorizations as following:
I –Industrial
N- Naturally Occurring Radioactive Materials (NORM)
M- Medical
S- Special Nuclear Materials (SNM)

Model 70 System Manual
Ludlum Measurements Inc. 10 May 2021
The top graph on the photo above shows the spectrum as it is accumulated along with the
acquisition time of the spectrum above. Below the spectrum, Nuclide ID is displayed if it has
been determined.
1. To begin spectrum acquisition on Screen 2, the user must press START (up arrow). The
spectrum will be recorded for the pre-set time as selected in the settings screen.
Alternatively, the user may select Continuous ID (select conti) in the instrument
Acquisition menu.
2. If the user desires, acquisition can be stopped at any time with the results of nuclide ID
by pressing the CANCEL/SET button. Otherwise, the nuclide ID will be displayed on
completion of the spectrum acquisition time.
3. After stopping spectrum acquisition, the results of the nuclide ID analysis will be
displayed in the Nuclide ID box on in the following format:

Model 70 System Manual
Ludlum Measurements Inc. 11 May 2021
Nuclide ID Strength
Cs-137 15.7
Where the strength represents signal-to-noise ratio for a nuclide identified, the user
may consider the values as:
-Below 10 as low confidence
-Between 10 and 15 as moderate confidence
-Above 15 as strong confidence
A maximum of up to five identified nuclides can be displayed. If there are more than five
nuclides identified, the user will be able to be scroll down.
If no identification can be made, the unit indicates a message of No Nuclides Found.
In case of presence of the nuclide not in the instrument’s database, the message of
Unknown will be displayed.
Setting Spectrum Nuclide ID Screen
If in the parameter Settings window of the Spectrum option is set to default Display: ON, the
accumulated gamma-spectrum will appear on the screen only upon a completed spectrum
acquisition. If the Spectrum option is set to Display: Continuous, the gamma-spectrum
accumulation progress will be displayed continuously over accumulation time.
Saving Spectrum
1. The user can stop recording at any time by pressing CANCEL/SET (down arrow). After
stopping acquisition, the following messages on the screen’s bottom window will
appear: Resume, Save, and Cancel.
Pressing the ENTER/SAVE to save the spectrum (the unit will
automatically assign the file name).
Save Spectrum - ENTER/SAVE
Cancel Save - Cancel/SET
Resume Spectrum -START

Model 70 System Manual
Ludlum Measurements Inc. 12 May 2021
Pressing CANCEL will cancel the current dose recording and clear all
data associated with this spectrum recording (completely cancel the
spectrum acquisition). The original Screen 2 will appear.
Pressing START will resume recording of the spectrum.
If during the intermediate stop (prior of reaching the pre-set time) the ENTER/SAVE button was
pressed, the spectrum will be saved with an automatic file name.
2. After saving the spectrum, the following tips over corresponding button controls appear
on the display: UP, BACK, and DOWN. The UP and DOWN are inactive in this version.
Press BACK to get back to Screen 2 Nuclide ID.
The instrument can be switched to Screen1 (Search + Dose) by pressing the ENTER/SAVE
button.
3. The user can save as many spectrums as the instrument memory allows by consequently
pressing START and ENTER/SAVE. The instrument can save up to one thousand of 1024
channel spectra.
However, it is not recommended to keep a large number of spectra in memory since it will
substantially increase the downloading time onto a PC.
4.6 SETTINGS, Screen 3
The settings screen is used so the users can configure the system to operate for their particular
monitoring environment.
Long press on the CANCEL/SET button (>3 sec) on Screen 1 (Search + Dose) or Screen 2
(Spectrum/Identify). If the START/STOP button option is not active, Screen 3 will appear.
This menu permits the user to set up the required operating parameters. Use the UP/DOWN
buttons to select (highlight) the required selection then ENTER to activate this selection. Inside
each menu use UP/DOWN button action to select a parameter, and then utilize the ENTER and
UP/DOWN button action to change the item.

Model 70 System Manual
Ludlum Measurements Inc. 13 May 2021
1. The user can select the various parameters desired to modify from the displayed list
on Screen 3 by pressing the ‘↑’ up or ‘↓’ down buttons to navigate through the
settings menu. The parameter selected to be modified will be highlighted.
2. To display the list of options available for the specific parameter, press ENTER/SAVE
once the selected parameter has been highlighted. A list of optional values for the
parameter in question is displayed as shown in the figure above.
3. The user can navigate through the list of values by pressing the ‘↑’ up or ‘↓’ down
arrows until the desired value has been highlighted.
4. When the desired value has been highlighted, press ENTER/SAVE to select the value.
5. Once the selection is made, the program returns to the main Settings screen category
(main Screen 3).