ORTEC Fission Meter FM-P3 User manual

ORTEC ®
Fission Meter ®(FM-P3)
Portable Neutron Source Identification System
Software v. 1.5.8
User’s Manual
ORTEC®Part No. 931026 060118
Manual Revision D Printed in USA

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Copyright ©2018, Advanced Measurement Technology, Inc. All rights reserved.
ORTEC® is a registered trademark of Advanced Measurement Technology, Inc. All other trademarks used herein are the property of
their respective owners.

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TABLE OF CONTENTS
FIGURES................................................................................................................................................ v
SAFETY INSTRUCTIONS AND SYMBOLS .............................................................................................. vii
CLEANING INSTRUCTIONS.................................................................................................................. vii
1. GETTING STARTED .........................................................................................................................1
1.1 Inspecting for Shipping Damage ........................................................................................................1
1.2 Unpacking the Fission Meter .............................................................................................................1
1.3 Setup and Startup ..............................................................................................................................2
1.3.1 The Trimble Ranger ...............................................................................................................2
1.3.1.1 TURNING THE RANGER ON AND OFF ..............................................................................2
1.3.2 The Neutron Detector Panel Assembly .................................................................................2
1.3.2.1 CONNECTING AND CABLING THE PANELS TOGETHER..........................................................3
1.3.2.2 LOADING/CHANGING THE PANEL BATTERIES....................................................................5
1.3.2.3 TURNING THE PANEL ASSEMBLY ON AND OFF..................................................................6
1.3.2.4 UNFOLDING THE PANEL ASSEMBLY.................................................................................6
1.4 Transferring Data from the Trimble Ranger to Another Computer...................................................6
1.4.1 Connecting the Trimble Ranger Directly to Another Computer............................................6
1.5 Shipping the Fission Meter ................................................................................................................7
1.5.1 Packing the Instrument in the Travel Case............................................................................7
1.5.2 Shipping Label Required ........................................................................................................7
2. MODES OF OPERATION .................................................................................................................9
2.1 Data Acquisition Modes.....................................................................................................................9
2.1.1 Mobile Search Mode .............................................................................................................9
2.1.2 Static Search Mode................................................................................................................9
2.1.3 Characterization Data Collect (“Triage”) Mode...................................................................10
2.2 How the Fission Meter Acquires and Stores Data ...........................................................................10
2.2.1 Data File Contents and Filenames .......................................................................................10
3. SOFTWARE GUIDE........................................................................................................................11
3.1 Startup Sequence.............................................................................................................................11
3.2 Mobile Search Mode........................................................................................................................11
3.3 Static Search Mode..........................................................................................................................14
3.3.1 Nearby and Distant Fission Sources ....................................................................................14
3.3.2 Counting in Static Search Mode ..........................................................................................15
3.3.2.1 CREATING A LOCAL BACKGROUND FILE .........................................................................15
3.3.3 Advanced Static Search .......................................................................................................17
3.4 Characterization Data Collect (Triage) Mode ..................................................................................17
3.4.1 Advanced Characterization Mode .......................................................................................18
3.4.2 Emailing Data from the Ranger ...........................................................................................19
3.4.3 Graphing the Data ...............................................................................................................20
3.5 Triage: Reachback to the U.S. Department of Energy .....................................................................21

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MAINTENANCE .............................................................................................................23
A.1 Maintenance Intervals.....................................................................................................................23
A.2 Changing the Battery Tube Cap O-Rings..........................................................................................23
A.3 Changing the Desiccant Plugs ..........................................................................................................24
A.4 Updating or Reinstalling the Fission Meter Software......................................................................28
SPECIFICATIONS ............................................................................................................31
B.1 Panel Assembly Electronics..............................................................................................................31
B.2 Fission Meter Controller (Trimble Ranger 3L) .................................................................................31
B.3 Electrical and Mechanical ................................................................................................................31
B.3.1 Serial Cable Pinouts .............................................................................................................32
FIRMWARE COMMANDS ..............................................................................................33
C.1 Fission Meter Command Summary .................................................................................................33
C.2 Multiplicity Counter Data Record Formats Ver. VI (Six Acq. Modes) ..............................................34
C.2.1 Acquisition Mode 1A Format (DRM = 1)..............................................................................34
C.2.2 Acquisition Mode 2A & 2C Format (DRM = 2 or 3)..............................................................36
C.2.3 Acquisition Mode 1B and 2B Format (DRM = 4 or 5) ..........................................................38
C.2.4 Total Cycle Count Format (DRM = 6)...................................................................................40
C.2.5 REAL-TIME REPORTING MODE ............................................................................................41
C.2.6 Instrument Parameters Format...........................................................................................42
C.2.7 Status Word —A Format.....................................................................................................42
C.2.8 Status Word —B Format.....................................................................................................43
C.2.9 Valid Command Response...................................................................................................43
C.2.10 Data Acquisition Complete (Returned in Both Free-Run and Triggered Modes)................43
C.3 Multiplicity Counter Communications Protocol and Commands Ver. VI (Six Acquisition
Modes).............................................................................................................................................43
C.3.1 BAUD Rate and Format........................................................................................................43
C.3.2 Data Flow Control................................................................................................................44
C.3.3 Request Data Transfer (Ignored If in an Acquisition Cycle).................................................44
C.3.4 DATA Request Mode (DRM) Format ...................................................................................44
C.3.5 Request Instrument Parameters .........................................................................................45
C.3.6 Set Instrument Parameters (Ignored if in an Acquisition Cycle) .........................................45
C.3.7 Cnt_stop and Acq_mode Word Format ..............................................................................46
C.3.8 Start Data Acquisition..........................................................................................................46
C.3.9 Stop Data Acquisition ..........................................................................................................46
C.3.10 Reset Instrument .................................................................................................................46
C.3.11 Set Real Time Data Recording Mode On/Off.......................................................................47
C.3.12 Operational Notes ...............................................................................................................47

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FIGURES
Figure 1. Fission Meter Panels in Padded Travel Case (l); Empty Case (r)..........................................................2
Figure 2. Panel Assembly Features.....................................................................................................................3
Figure 3. Hinge Link and Captured Quick-Connect Pins. ....................................................................................4
Figure 4. Cable the Panels Together and the Master Panel to the Ranger. .......................................................4
Figure 5. Battery Tube Cap. ................................................................................................................................5
Figure 6. Remove the Battery Tube Cap and Insert the Batteries in the Correct Orientation...........................5
Figure 7. Panel Status Readout...........................................................................................................................6
Figure 8. Storing the Hinge Links. .......................................................................................................................7
Figure 9. The Main Screen................................................................................................................................11
Figure 10. Mobile Search Mode —Searching. .................................................................................................12
Figure 11. The Red Dot Indicates an Alarm. .....................................................................................................12
Figure 12. Adjust the Alarm Thresholds and Fix the Background or Allow It to Auto-Update. .......................13
Figure 13. Sigma Y2F Alert. Clear Alarm and Keep Counting or Change to Characterization Mode................13
Figure 14. Neutron Source Present. Switch to Characterization Mode. ..........................................................14
Figure 15. Static Search Mode..........................................................................................................................15
Figure 16. Unfold Panels and “Clamshell” Thin Sides Around Object..............................................................16
Figure 17. Static Search Mode Settings............................................................................................................16
Figure 18. Suspicious Neutron Source —Switch to Characterization Mode. ..................................................16
Figure 19. Advanced Static Search. ..................................................................................................................17
Figure 20. Acquire Data for Further Analysis....................................................................................................18
Figure 21. Characterization Mode Settings Screen. .........................................................................................18
Figure 22. Advanced Characterization Screens. ...............................................................................................19
Figure 23. Preparing the Email. ........................................................................................................................19
Figure 24. Email with 2A.log File Attached.......................................................................................................20
Figure 25. Multiplicity Plot. ..............................................................................................................................20
Figure 26. Y2F Distribution Compared to Poisson Curve for Current or Previously Collected Data. ...............21
Figure 27. List of Triage Authorities..................................................................................................................22
Figure 28. O-Ring Positions on Battery Tube Cap.............................................................................................24
Figure 29. Humidity Indicator; blue —OK, lavender/pink —replace..............................................................24
Figure 30. Humidity Indicator Removal Tool....................................................................................................25
Figure 31. Unscrew and Gently Pull Out the Humidity Indicator. ....................................................................25
Figure 32. Remove the Indicator Cap, Exposing the Spent Desiccant..............................................................26
Figure 33. Cut Open the Packet and Refill the Indicator Cartridge. .................................................................26
Figure 34. Gently Tap the Cartridge then Top Off............................................................................................26
Figure 35. Replace the Washer and Clean the Cap Seat. .................................................................................27
Figure 36. Torque the Cap to Hand-Tight.........................................................................................................27
Figure 37. Reinstall the Indicator and Torque to Hand-Tight...........................................................................28
Figure 38. Uninstall the Previous Version of the Fission Meter Software........................................................28
Figure 39. Install the New Software to “Device.”.............................................................................................29

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SAFETY INSTRUCTIONS AND SYMBOLS
This manual contains up to three levels of safety instructions that must be observed in order to avoid personal
injury and/or damage to equipment or other property. These are:
DANGER Indicates a hazard that could result in death or serious bodily harm if the safety instruction
is not observed.
WARNING Indicates a hazard that could result in bodily harm if the safety instruction is not observed.
CAUTION Indicates a hazard that could result in property damage if the safety instruction is not
observed.
Please read all safety instructions carefully and make sure you understand them fully before attempting to
use this product.
In addition, the following symbol might appear on the product:
ATTENTION –Consult the manual in all cases where this symbol is marked in order
to determine the nature of the potential hazards and any actions that must be taken
to avoid them
DANGER –Hazardous voltage
Protective earth (ground) terminal
Please read all safety instructions carefully and make sure you understand them fully before attempting to
use this product.
CLEANING INSTRUCTIONS
To clean the instrument exterior:
•Remove all batteries from the instrument.
•Remove loose dust on the outside of the instrument with a lint-free cloth.
•Remove remaining dirt with a lint-free cloth dampened in a general-purpose detergent and water
solution. Do not use abrasive cleaners.
•Allow the instrument to dry completely before reconnecting it to the power source.
CAUTION To prevent moisture inside of the instrument during external cleaning, use only enough
liquid to dampen the cloth or applicator.

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1. GETTING STARTED
The ORTEC® Fission Meter® is an easy-to-use, portable neutron detection system designed to locate illicitly
trafficked special nuclear materials (SNM), particularly shielded sources. It combines software developed by
the Lawrence Livermore National Laboratory with two panels of moderated 3He neutron detectors, enabling
you to collect and communicate crucial data about suspicious neutron sources to the U.S. Department of
Energy’s Emergency Operations Center.
• The Fission Meter is controlled by a rugged, water- and dust-resistant Trimble® Ranger™ 3L computer
running under the Microsoft® Windows® Embedded Handheld 6.5 Professional operating system.
• The Ranger has a 34-hour rechargeable battery. It is also supplied with a power adapter that operates
from a 120 V ac power source.
• The highly water- and dust-resistant Fission Meter panel assembly operates up to 14 hours on 16
disposable D-cell batteries. The panel assembly automatically switches to standby mode after 8 hours
if no commands are received from the Ranger. Batteries can be replaced, one panel at a time, without
interrupting data collection.
• Each Fission Meter panel has a heavy-duty nylon carrying case that protects it from scuffs and dents,
and clearly indicates the thin (detector) and thick (polyethylene shielding) sides of each detector
panel for foolproof deployment during measurements.
• The only routine maintenance required is charging the Ranger battery and changing the D-cell
batteries that power the panel assembly. From time to time, two desiccant plugs in the panel
assembly and the O-rings on the battery tube caps must also be changed.
Hardware setup and startup are discussed in Section 1.3, software operation is discussed in Chapter 3, and
the maintenance schedule is in Section A.1. The firmware command set is described in APPENDIX C.
1.1 Inspecting for Shipping Damage
If the shipping carton(s) arrives with externally visible damage, do not unpack it. Notify the carrier and make
arrangements to file a damage claim. In all cases of shipping damage, it is the customer's responsibility to file
a damage claim.
If, during unpacking, you find concealed damage, notify the carrier and file a claim. Be sure to save all packing
materials, waybills, and other such documentation to establish claims.
Contact our Global Service Center or your ORTEC representative for further instructions.
1.2 Unpacking the Fission Meter
Figure 1 shows the Fission Meter in its padded, waterproof travel case.
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We strongly recommend
transporting and shipping the Fission Meter in this case.
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When properly sealed, the travel case and contents will float.

ORTEC®Fission Meter®(FM-P3) Portable Neutron Source Identification System 931026D / 060118
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Figure 1. Fission Meter Panels in Padded Travel Case (l); Empty Case (r).
The bill of materials for your Fission Meter may vary, but at minimum you will receive the following:
• Fission Meter panels with black, shielded interconnecting cable, and two (2) inter-panel hinge pieces.
• Trimble Ranger 3L with user instructions, AC power adapter, carrying strap, and 9-pin serial cable.
• Fission Meter user manual (P/N 931026D).
• Pressurized 3He tube shipping note (P/N 932722).
• Padded carrying cases.
• Fission Meter Spare Parts Kit (P/N 1109403) containing at minimum battery tube cap O-rings, O-ring
grease, disposable latex gloves, humidity indicator removal tool, and bulk desiccant packets .
1.3 Setup and Startup
1.3.1 The Trimble Ranger
See the Ranger’s user materials for instructions on attaching the carrying strap, accessing the SD card drive,
and charging the 34-hour battery.
1.3.1.1 TURNING THE RANGER ON AND OFF
To turn on the Ranger, lower-left, green power button ( ) until the PDA boots and Windows Mobile starts.
To turn the PDA off, press and hold the green button for 1–2 seconds, then release it. This will display a Power
Menu screen that will give you the choice of aligning the touchscreen, restarting Windows, or shutting down
the PDA. Tap Shutdown.
1.3.2 The Neutron Detector Panel Assembly
Figure 2 shows the master panel with the top of its padded case open, the so-called “thin” (3He detector) side
up, with the second/slave panel visible on the far right. The master panel includes the power button, count-
rate/battery readout, serial port for the Trimble Ranger, inter-panel cable jack, and humidity indicator. The

1. GETTING STARTED
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so-called “thick” side of each panel is covered with a polyethylene neutron moderator. Both panels have
battery tubes; these are discussed in Section 1.3.2.2.
Both the Ranger and the Fission Meter panels are highly water- and dust-resistant, with respective ingress
protection ratings of IP67 and IP63.
Figure 2. Panel Assembly Features.
1.3.2.1 CONNECTING AND CABLING THE PANELS TOGETHER
CAUTION: Place the two Fission Meter panels flat on the floor or other smooth, horizontal surface, with
the “thin” (3He tube) sides down. DO NOT stand them on end before they are connected together. DO NOT
allow them to fall over during assembly or use. This is a precision scientific instrument that must be
protected from shock.
1) Connect the panels using the captured quick-connect pins and two (2) hinge links; see Figure 3.
2) Connect the panels with the black, shielded cable, taking care to correctly orient the connectors before
pushing and turning them. Do not apply excess force. When correctly connected, the cable ends have an
IP63 ingress protection rating.
3) Slide the padded carrying case onto each panel (if not already in place), and secure each with its hook-
and-loop closures.
4) Connect the Trimble Ranger to the master Fission Meter panel with the 9 pin serial cable.
DANGER High voltages are present inside the panel assembly casings. Do not attempt to open the panel
housings. The only user-accessible/maintainable parts are the battery tube and cap, and the humidity
indicator/desiccant.

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Figure 3. Hinge Link and Captured Quick-Connect Pins.
Figure 4 shows the two panels and Ranger cabled together.
Figure 4. Cable the Panels Together and the Master Panel to the Ranger.

1. GETTING STARTED
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1.3.2.2 LOADING/CHANGING THE PANEL BATTERIES
Each panel runs on eight (8) D-cell batteries, which are loaded positive terminal down into a removable tube
on the top of each panel, on the side of the panel that is not hinged. Each battery tube is sealed with an
O-ring-sealed, spring-loaded cap, shown in Figure 5.
Figure 5. Battery Tube Cap.
To load/change the batteries:
1) Press firmly on the cap with your palm and rotate it approximately 1/16 turn counterclockwise. This will
release the entire battery tube.
2) Rotate the tube as needed to remove it from the panel.
3) Depress the opposing buttons that hold the cap on the tube, and pull the cap off; see the instruction label
on the tube (Figure 6).
4) Remove the old batteries (if present). Then, holding the tube close to horizontal, slide the new batteries
into place positive terminal down. CAUTION: Do not hold the tube vertically and drop the batteries in;
doing so may break the positive contact assembly at the bottom of the tube. See the instruction label on
the tube.
Figure 6. Remove the Battery Tube Cap and Insert the Batteries in the Correct Orientation.
5) Reverse the above steps.
Change a panel’s batteries when the voltage drops to <8.5V or after 3 months, whichever comes first.
CAUTION: Remove the batteries if the instrument will not be used for more than 30 days. To keep moisture
out of the battery tubes, be sure to change the two O-rings on the cap according to the schedule and
instructions in Section A.2.

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1.3.2.3 TURNING THE PANEL ASSEMBLY ON AND OFF
To turn the panel assembly on, press and hold the ON button for approximately 2 seconds. The readout on
top of the master panel activates, displaying the current neutron count rate in cps and the voltages for the
two battery tubes, as shown in Figure 7.
Figure 7. Panel Status Readout.
To turn the panel assembly off, press and hold the ON button for 2–3 seconds until the display goes blank.
1.3.2.4 UNFOLDING THE PANEL ASSEMBLY
In Mobile Search Mode you will generally keep the panel assembly folded, thin (detector) side out, as
indicated by the markings on the carrying case.
For measurements in Static and Characterization modes, use the handles on the sides of the panel assemblies
(not the top handles) to unfold the panel assembly, turn the thin sides toward the item to be measured, and
enfold (“clamshell”) the item as much as possible, as shown in Figure 16 on page 16.
1.4 Transferring Data from the Trimble Ranger to Another Computer
The easiest way to transfer data from the Ranger to a computer is by using the Micro SD card and USB adaptor
provided. Additionally, the Micro SD card can be used in an Android-based mobile phone to transfer data
directly by email to the desired recipient.
1.4.1 Connecting the Trimble Ranger Directly to Another Computer
The Fission Meter is designed as a standalone system, however, there are cases in which it will be useful or
necessary to connect with another computer. For example, you might wish to connect to a computer via
cable in order to transmit data via email, perhaps for expert analysis. In addition, unless your Ranger is
configured for wireless networking, you must connect to a computer to install Fission Meter software
updates or to reinstall/repair the original Fission Meter software. You might also wish to transfer data files
from the Ranger to another computer.
NOTE The Ranger is a standard Windows Mobile 6.5 computer. Any of the standard communication
techniques (wireless networking, etc.) can be used to establish communication with the internet for remote
transfer of email and files.
IMPORTANT: The battery voltage on each panel must be >8.5 V or the Fission Meter may not function
accurately!
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IMPORTANT Before connecting the Ranger to another computer for the first time, install Windows Mobile
Device Center on the host computer first.Otherwise, the Ranger might not communicate properly with
the computer. Contact our Global Service Center if you need assistance.

1. GETTING STARTED
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1) From the Microsoft support webpage, download and install Windows Mobile Device Center.
2) Connect the Ranger to the computer via USB. Windows will indicate that the hardware driver has been
installed.
1.5 Shipping the Fission Meter
1.5.1 Packing the Instrument in the Travel Case
Reverse the setup and startup instructions in Section 1.3. To ensure that the hinge links are not misplaced
when the panels are disconnected from one another, run the master panel’s quick-connect pins through the
the center hole of each hinge link; see Figure 8.
Figure 8. Storing the Hinge Links.
1.5.2 Shipping Label Required
The Fission Meter contains pressurized 3He tubes, the transport of which by commercial air carrier is
regulated. Before shipping the Fission Meter, be sure to read the accompanying Technical Note,
“Transporting ORTEC Instruments with Pressurized 3He Tubes” (Part No. 932722). The required shipping label
discussed in the Technical Note is commercially available. If you have any questions or cannot obtain shipping
labels, contact your ORTEC Representative or our Global Service Center; see our website for contact details.

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2. MODES OF OPERATION
2.1 Data Acquisition Modes
The Fission Meter has three data collection modes: Mobile Search, Static Search, and Characterization Data
Collect (“Reachback”).
2.1.1 Mobile Search Mode
Mobile Search Mode is a survey mode that allows you to monitor total neutron count rate and the Feynman
variance moment, Y2F. These two monitoring parameters have their own “strip chart” showing parameter
values with respect to time; and a “barometer” that gives instantaneous values against an alarm threshold,
based on standard deviations. This mode is designed to identify slightly elevated count rates in a search area,
as well as significant neutron sources. If a significant neutron source is present (as indicated by an obviously
elevated count rate), the strip chart can help you maximize the count rate and localize the source.
Once a source is localized, you should switch to Characterization Data Collect Mode to obtain more detailed
data for Triage support. Bear in mind that even when the strip chart count rate is maximized, the source could
still be a significant distance away, behind various walls and barriers. To maximize detection efficiency, the
Characterization Data Collect measurement should be performed as close to the source as possible. Because
of this, it might be necessary to continue Mobile Search Mode into other rooms or locations to better localize
the source.
If the Mobile Search results in a Count Rate or Y2F Alarm, but the count rate is only slightly elevated and
source localization is unsuccessful, this could indicate the presence of a non-cosmic neutron source or just
an elevated background count rate (such as the ship effect). In this case, you should place the Fission Meter
in a fixed location and switch to Static Search Mode. In the Static Search Mode, Feynman moments are
examined more closely to help you and Triage determine the source of the neutron count rate by partitioning
the count rate into cosmic and non-cosmic fractions.
If an object is already suspect, you can skip this mode and move directly to the Static Search or
Characterization Data Collect mode.
2.1.2 Static Search Mode
The Static Search Mode can be used to verify the presence or absence of a non-cosmic source of a strength
comparable to or less than the typical background neutron count rate. In Static Search Mode, the Feynman
moments are examined more closely to enable partitioning of the total count rate into cosmic and non-
cosmic fractions. The Feynman moments are distinct for cosmic source neutrons and non-cosmic source
neutrons (including fission and Poisson sources). This allows the total count rate to be separated into a cosmic
source fraction and a non-cosmic source fraction. The ratio of cosmic to non-cosmic neutrons is displayed on
the bar graph at the top of the screen.
Static Search Mode is used where a non-cosmic source is suspected, due to information such as a mobile
search Count Rate Alarm or Y2F Alarm, but when localization of the source in Mobile Search Mode has been
unsuccessful.

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To perform a static search, place the instrument in the area where the alarm occurred, or where there is an
otherwise suspected source, and start the Static Search Mode. Static Search Mode relies on a static count
rate. Therefore, it is critical that the instrument remain static with respect to the area being monitored. This
measurement can take several hours to obtain an accurate partitioning of the total count rate into cosmic
and non-cosmic fractions. If the count rate is adequate and the source is significantly multiplying, Static
Search will indicate so, and you will switch to the third mode, Characterization Data Collect.
The Advanced Static Search Mode is discussed in Section 3.3.3.
2.1.3 Characterization Data Collect (“Triage”) Mode
Following the determination by Static Search mode that an actual fissioning neutron source is present, this
mode allows for the collection of much more data (~1,000,000 counts) to be transmitted for expert analysis.
An e-mailing feature allows you to connect the Ranger PDA to a PC with internet access so suspicious neutron
data can be sent to the appropriate authorities for analysis and recommended action (see Section 3.4).
This mode also allows you to graph the characterization data in two ways. The first is the multiplicity plot. It
shows a Poisson (random) distribution matched in mean count to the data. Deviation of the data from a
purely random distribution could indicate the presence of non-cosmic neutrons. The second plot is the
neutron lifetime, which can aid in detecting moderating material such as polyethylene shielding.
The Advanced Characterization Mode is discussed in Section 3.4.1.
2.2 How the Fission Meter Acquires and Stores Data
The Fission Meter software fetches data from a hardware buffer every 0.25 seconds and updates the Ranger
display accordingly. We refer to this 0.25 second interval as a data acquisition cycle.
2.2.1 Data File Contents and Filenames
The data for each acquisition in Characterization Mode are written to a 2A.log file, which contains
information about the hardware settings and a list of the neutron multiplicities in the Fission Meter’s time
subgates for each data acquisition cycle.
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The filenames are based on the date and time data acquisition
begins, and are formatted as:
MMDDYYYY_HHmmSS-2A.log
For example, file 03102018_142032-2A.log was created on March 10, 2018, at 2:20.32 p.m.
2
The Real_Time.log data files are for a specialized purpose and can be deleted.

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3. SOFTWARE GUIDE
3.1 Startup Sequence
• Set up the Fission Meter panels and connect the Ranger to the panel assembly according to
Section 1.3.2.
• Press and hold the Ranger’s lower-left, green power button ( ) until the PDA boots and Windows
Mobile starts.
• Press and hold the panel assembly ON button until the readout displays the current neutron count
(cps) and battery voltages. Battery voltage for each panel must be >8.5 V or the software might not
calculate correctly. Each battery tube requires eight (8) D-cell batteries, loaded positive terminal
down, as described in Section 1.3.2.2.
• On the Ranger, tap the Windows Start button ( ), then Fission Meter ( ) to open Fission Meter
software main screen (Figure 9). The lower-right indicator is blue if the count rate is above
background is 0–50 cps, amber if 50–100 cps, and red if >100 cps.
• Decide which detection mode to use and tap the appropriate button.
Figure 9. The Main Screen.
3.2 Mobile Search Mode
The Mobile Search Mode screen is shown in Figure 10. This is the survey mode. Typically, you will survey with
the panels folded, thin sides always facing out.
The screen shows two pairs of data displays:
• Sigma C strip chart and barometer —The strip chart tracks counts above background in standard
deviations. The barometer indicates count rate above background.

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—Blue = 0–40 cps
—Yellow = 40–100 cps
—Red = >100 cps.
• Sigma Y2F (Feynman variance) strip chart and barometer —The strip chart tracks the value of Y2F,
which is zero for cosmic neutrons and non-zero for correlated (non-cosmic) neutrons. The barometer
indicates the σY2F factor. Blue = 0–0.02 σY2F; yellow = 0.02–0.1 σY2F; and red = 0.1–0.3 σY2F.
Figure 10. Mobile Search Mode —Searching.
On each trace, if an alarm is generated during a data acquisition cycle, the corresponding point on the strip
chart is a red circle instead of black (Figure 11).
Figure 11. The Red Dot Indicates an Alarm.
The Settings button opens the screen shown in Figure 12.
The default settings are as follows:
• Alarm Threshold σN, the net neutron alarm, is 3 standard deviations.
• Alarm Threshold σ Counts, net neutron count-rate alarm, is 5 times the change in count rate, in cps.
• Alarm Threshold σY2F, the Feynman variance, is 3.5 times the change in Y2F.
• Background (cps) can either be automatically calculated (the default) or can be set by tapping the
Calc button.