DURRIDGE RAD7 User manual

Electronic Radon Detector
User Manual
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It is recommended that the RAD7 be returned to DURRIDGE Company annually for recalibration.
Owner:
____________________________
Serial #:
______________
SERVICE RECORD
Date:
Service:

WARNING
Opening the cover of this instrument is likely to expose dangerous voltages.
Disconnect the instrument from all voltage sources while it is being opened. Due to
battery power, the instrument may still be dangerous.
Using this instrument in a manner not specified by the manufacturer may impair the
protection provided by the instrument.
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TABLE OF CONTENTS
INTRODUCTION 10
Points of special note 10
Shipping and Contact Information 10
1 GETTING STARTED: YOUR FIRST DAY WITH THE RAD7 11
1.1 Unpacking 11
RAD7 Packing List 11
1.2 General Safety Instructions 12
1.2.1 Air Travel 13
1.3 Taking a Look 13
The RAD7 Professional Electronic Radon Detector 13
1.4 Starting a Two-day Test 14
RAD7 Normal Con!guration 14
End-of-Run Printout 15
1.5 Starting a SniffTest 16
RAD7 SNIFF Con!guration 16
2 BASICS OF RAD7 OPERATION 18
2.1 Introduction 18
2.1.1 The Keypad 18
2.1.2 Command List 18
2.2 Test 18
2.2.1 Test Status 18
2.2.1a Quick Save-and-Restart 19
2.2.2 Test Start and Test Stop 20
2.2.3 Test Save 20
2.2.4 Test Clear 20
2.2.5 Test Purge 20
2.2.6 Test Lock 21
2.2.7 Test Sleep 21
2.2.8 Test Print 21
2.2.9 Test Com 21
2.3 Data 21
2.3.1 Data Read 22
2.3.2 Data Print 22
2.3.3 Data Com 23
2.3.4 Data Summary 23
Table of Contents
3

2.3.5 Data Free 23
2.3.6 Data Delete 23
2.3.7 Data Renumber 24
2.3.8 Data Erase 24
2.4 Setup 24
2.4.1 Setup Protocol 24
Table 2.4.1 Preset protocols 24
2.4.2 Setup Cycle 25
2.4.3 Setup Recycle 25
2.4.4 Setup Mode 25
2.4.5 Setup Thoron 26
2.4.6 Setup Pump 26
2.4.7 Setup Tone 26
2.4.8 Setup Format 27
2.4.9 Setup Units 27
2.4.10 Setup Savuser 27
2.4.11 Setup Clock 27
2.4.12 Setup Review 28
2.5 Special 28
2.5.1 Special Ident 28
2.5.2 Special SPrOn 28
2.5.3 Special SPrOff29
2.5.4 Special SetBaud 29
2.5.5 Special Status 29
2.5.6 Special Start 29
2.5.7 Special Stop 29
2.5.8 Special Comspec 29
2.5.9 Special ComAll 29
2.5.10 Special SPrAll 29
2.5.11 Special S-Load 29
2.5.12 Special Version 29
2.5.13 Special Model 29
2.5.14 Special Serial 29
2.5.15 Special Beep 30
2.5.16 Special Relays 30
2.6 Infrared Printer 30
Alpha Energy Spectrum 31
3 BASICS OF RAD7 TECHNOLOGY: HOW IT WORKS 32
3.1 Introduction 32
Table of Contents
4

3.2 Radon and Thoron Decay Chains 32
Radon Decay Chain 33
Thoron Decay Chain 33
3.2.1 Radon-222 (Radon) 34
3.2.2 Radon-220 (Thoron) 34
3.3 Continuous Monitors 34
3.4 Sniffers 35
3.5 Working Level 35
3.6 RAD7 Solid-State Detector 36
3.6.1 RAD7 Calibration and Data Correction 36
3.7 RAD7 Spectrum 37
3.8 Windows 38
3.9 Isotope Equilibrium 39
3.10 Modes: Sniffand Auto 40
3.11 Background 40
3.11.1 Short-lived Radon and Thoron Daughters 41
3.11.2 Adsorbed Radon Gas 41
3.11.3 Intrinsic Background 41
3.11.4 Long-lived Radon Daughters 41
3.11.5 Contamination by Radon, or Thoron, Producing Solids 41
3.11.6 Other Alpha Emitters 42
3.11.7 Beta and Gamma Emitters 42
3.12 Precision & Accuracy 42
3.12.1 Dry operation 42
Table: 3.12 Typical RAD7 precision based on counting statistics only. 43
3.12.2 Humidity Correction 43
3.12.3 Concentration Uncertainties 43
3.13 Spectrum Examples 45
3.13.1 Operational Radon Spectra 45
3.13.2 Thoron Spectra 46
3.13.3 Combination Spectra 47
3.13.4 Pathological Spectra 49
4 USING THE RAD7: MEASURING RADON AND THORON IN AIR 51
4.1 Introduction 51
4.2 Continuous Monitoring 51
4.2.1 Preparation 51
4.2.2 Purging 51
4.2.3 Test Location 52
Table of Contents
5

4.2.4 Test Protocol 52
4.2.5 To Print Or Not To Print 53
4.2.6 Running the Test 53
4.2.7 Security and Quality Control 53
4.2.8 Finishing the Run 54
4.2.9 Examining the Data 54
4.2.10 Very Short Term Monitoring 54
4.3 Sniffing 55
4.3.1 Why Sniff? 55
4.3.2 Locating Radon Entry Points 55
4.3.3 Preparation 55
4.3.4 Purging 55
4.3.5 Running the Test 55
4.3.6 Drilled Sampling Points 56
4.3.7 Spot Readings 56
4.4 Grab Sampling 56
4.4.1 Applicability 56
4.4.2 Preparation 57
4.4.3 Protocol 57
4.4.4 Taking the Sample 57
4.4.5 Analysis 57
4.5 Thoron Measurement 57
4.5.1 Thoron and Radon 57
4.5.2 Thoron Measurement Issues 58
4.5.3 Calculation and Interference Correction 58
4.5.4 Avoiding Longer Lived Decay Products 59
4.5.5 Standard Thoron Setup, Thoron Calibration and Flow Rate 59
4.5.6 Calculating Sample Decay 59
4.5.7 Calculating Internal Cell Concentration 59
4.5.8 Internal Cell Thoron Sensitivity Calibration 59
4.5.9 Setting up a Thoron Measurement 60
4.5.10 Thoron Mode 60
Recommended RAD7 Thoron Con!guration 61
4.5.11 Thoron Measurements in Standard Radon Mode 61
4.6 Managing Background 61
4.7 Air$ow Rate Limits 62
4.7.1 Maximum Air$ow Rate 62
4.7.2 Minimum Air$ow Rate 62
4.8 Harsh and Hazardous Environments 63
4.8.1 Splashing Water 63
Table of Contents
6

4.8.2 Dusty Environment 63
4.8.3 Radiation Hazard 63
5 USING RAD7 ACCESSORIES: TESTING SOIL AND WATER 64
5.1 Introduction 64
5.2 Radon in Water 64
5.2.1 The RAD H2O and Big Bottle Systems 64
5.2.2 The RAD AQUA Accessory 65
5.2.3 The WATER PROBE Accessory 65
5.3 Soil Gas Sampling 65
5.3.1 Application 65
5.3.2 The Soil Gas Probe Accessory 65
5.3.3 Soil Gas Probe Preparation 65
5.3.4 Running the Test 66
5.3.5 Interpreting the Data 66
5.4 Emission Measurements 66
5.4.1 Application 66
5.4.2 Open Loop Con!guration 66
5.4.3 Closed Loop Con!guration 67
5.4.4 Very Low Emission Rates 67
5.4.5 Bulk Emissions 67
5.4.6 Surface Emission 67
5.5 Supporting Accessories 68
5.5.1 Overview 68
5.5.2 The Range Extender 68
5.5.3 The DRYSTIK 69
6 COMPUTER CONNECTIVITY 70
6.1 Computer Connectivity Basics 70
6.1.1 Connecting the RAD7 to the Computer 70
Connecting the RAD7 to a Computer with the StarTech Adaptor 71
Connecting the RAD7 to a Computer with the Keyspan Adaptor 71
6.2 CAPTURE Software 72
6.2.1 Introduction to CAPTURE 72
6.2.2 CAPTURE Installation 72
CAPTURE Software running on Windows 72
6.2.3 Feature Summary 73
6.2.4 Downloading RAD7 Data 73
6.2.5 Graphing and Analysis 73
6.2.6 Real-Time RAD7 Monitoring 73
Table of Contents
7

6.2.7 CAPTURE CLOUD 73
6.3 RAD7 Communication Protocol 74
6.3.1 Communication Requirements 74
6.3.2 RAD7 Command Format 74
6.3.3 Parsing RAD7 Data 74
Table 6.3.3 RAD7 Data Record Content 75
6.3.4 Terminal Emulator Tips 76
6.4 Serial Port Speci!cations 76
6.4.1 Communication Protocol 76
Table 6.4.1a Serial Port Pin Assignments 76
Table 6.4.1b Communication Parameters 76
6.4.2 Extending the RS-232 Range 76
7 MAINTENANCE 77
7.1 Accessories - Usage and Care 77
7.1.1 Desiccant 77
7.1.2 Laboratory Drying Unit 77
Table 7.1.2 Laboratory Drying Unit Life 77
7.1.3 Small Drying Tube 77
Table 7.1.3 Small Drying Tube Life 77
7.1.4 Cascading Drying Tubes 78
7.1.5 Filters 78
7.1.6 Batteries 78
7.1.7 Real-time Clock and Non-volatile Memory 79
7.1.8 Printer and Adapter 79
7.2 RAD7 Operating ranges 79
Table 7.2 RAD7 Operating Ranges 79
7.3 Service and Repair 80
7.3.1 Calibration 80
7.3.2 Repair 80
7.3.3 Shipping 80
7.3.4 Upgrades 82
7.4 RAD7 Quality Assurance 82
7.4.1 Spectrum 82
7.4.2 Spill Factor (C Window to B Window) 82
8 TROUBLESHOOTING 83
8.1 LCD Display 83
8.1.1 Blank Display 83
8.1.2 Frozen Display 83
Table of Contents
8

8.1.3 Incomplete Or Garbage Characters 83
8.1.4 NVRAM Error 83
8.2 Readings 83
8.2.1 No Counts 83
8.2.2 Excessive Uncertainty In Reading 84
8.2.3 Run/Cycle Number 0000 84
8.3 Relative Humidity high 84
8.4 Water Catastrophe 84
8.5 Battery Voltage Low 85
8.6 Pathological Values and Error Messages 85
8.7 CAPTURE RAD7 Detection Failure 85
Appendix 1: WIRELESS INFRARED PRINTER 87
A1.1 Infrared Printer Description 87
A1.1.1 General Printer Information 87
A1.1.2 Printer Features 87
A1.1.3 Power Switch 87
A1.1.4 Indicator LEDs 87
A1.1.5 Push Buttons 87
A1.1.6 Sensors 87
Infrared Printer Component Locations and Functions 88
A1.2 Infrared Printer Operation 89
A1.2.1 Precautions 89
A1.2.3 Setup Mode 89
Table A1.2.3 Sel and Feed Functions 89
A1.2.4 Using the Printer 90
A1.3 Infrared Printer Maintenance 90
A1.3.1 Battery Installation 90
A1.3.2 Paper Installation 90
A1.3.3 Cleaning the Printer 91
A1.3.4 Cleaning the Print Head 91
A1.4 Wireless Infrared Printer Speci!cations 92
Table A1.4 Infrared Printer Speci!cations 92
Appendix 2: RAD7 Specifications 93
Table A2.1 Functional Speci!cations 93
Table A2.2 Technical Speci!cations 93
Table A2.3 Physical Speci!cations 94
Table of Contents
9

INTRODUCTION
e RAD7 is a highly versatile instrument that can form the basis of a comprehensive radon measurement
system. It may be used in many different modes for different purposes. is manual adopts a progressive
approach, in which there is, first, a simple, step-by-step description of how to get readings for a) real-time
monitoring, and b) sniffing. Next comes a more detailed description of the many features of the
instrument and how to access them. e rest of the manual covers a whole range of topics, in somewhat
arbitrary order. We recommend that, as soon as possible, you read the entire text, just so that you will have
an idea of what there is. While you can start to make good measurements on the first day of ownership of
the RAD7, it can take years to master the subtleties of radon and thoron behavior, and to appreciate the
full capabilities of the instrument.
We have tried to make the manual easy to use, with a useful table of contents. Please let us know how well
we have succeeded. If there are some topics inadequately covered, please tell us. We will issue updates
from time to time.
Points of special note
e RAD7 is a rugged and long-lasting piece of equipment. ere are many units still in daily use that
were sold ten years ago or more. However, it is a sophisticated, precision electronic device, and it is not
hermetically sealed, so please treat it with respect. Please do not allow water, other liquids or dirt to get
into the machine. If using it somewhere where it may get splashed, damaged, or exposed to rain, please
protect it. See Chapter 4.8.1.
e batteries are lead-acid technology, like a car’s. If lein a discharged state they will lose capacity. Aer
running the RAD7 on its batteries please recharge them as soon as possible (by plugging in the unit).
With careful use the batteries will last five years or more.
Finally, there is one security feature that is sometimes inadvertently set by an inexperienced, though
authorized, user; namely the keypad lockout. If the keypad ceases to function, and all you see is
DURRIDGE RAD7 on the display, just do the following: Hold down the [ENTER] and two arrow keys
until you hear a beep, release the three keys and immediately push [MENU]. You should then be rewarded
by >Test on the display. If the tone was set to OFF, then you will not hear the beep, so hold the three
keys down for three to four seconds, before releasing them and pushing [MENU], - try hold-down times a
little longer, or shorter, if, at first, you do not succeed.
Shipping and Contact Information
DURRIDGE U.S. Office
900 Technology Park Drive
Billerica, MA 01821 USA
Phone: [phone]
Fax: [phone]
DURRIDGE UK Office
Sheffield Technology Park
Cooper Buildings, Arundel Street
Sheffield S1 2NS, UK
Phone: [phone]
Email
[email protected]
Web
www.durridge.com
Introduction
10

1 GETTING STARTED: YOUR FIRST DAY WITH THE RAD7
1.1 Unpacking
First make sure you have everything you are supposed to have. Take the materials out of the packing boxes
and see if you have all the items shown in the diagram below, or on the packing list enclosed with the
shipment. If anything is missing, please email DURRIDGE immediately or call us at ([phone].
RAD7 Packing List
RAD7 and Case Accessories!
• RAD7 electronic radon detector
• 12V adaptor w/ 4 plugs
• 12V cord for custom applications
• RAD7 Carrying Strap
• Keys for RAD7 case
RAD7 Printer Supplies!
• Wireless infrared printer
• 4 AA alkaline batteries
• 6 Rolls printer paper
Drying Tubes and Desiccant!
• Gas drying unit
• Opener tool for drying unit
• 5 lbs desiccant
•4 drying tubes
RAD7 Filters!
• 5 RAD7 inlet filters
• 1 Dust filter
Section 1 Getting Started
11

RAD7 Packing List (Continued)
1.2 General Safety Instructions
For your own safety and the proper operation of
RAD7:
DO NOT spill liquids onto the machine.
DO NOT expose operating panel of machine to
rain or any other excess moisture.
DO NOT allow liquid to be sucked into inlet tube.
If you intend to use the instrument in a harsh
environment, give it some protection. Even just a
transparent plastic bag enclosing the RAD7 (but
not the air sampling tube) can protect it from
splashing mud and water. Allowing the dry air
from the RAD7 outlet to exhaust into the interior
of the bag will keep the RAD7 in a clean and dry
environment.
If liquid does get into the machine, please
disconnect the power cord, turn offthe power
switch, and follow the instructions in Chapter
4.8.1, Harsh and Hazardous Environments:
Splashing Water. It will be necessary to return the
RAD7 to DURRIDGE for repair.
Do not use your RAD7 if the instrument is
damaged or malfunctioning. Please call, or email,
the DURRIDGE service department, who will
advise what to do about the problem.
Replace a frayed or damaged power cord
immediately. Electrical equipment may be
hazardous if misused. Keep away from children.
Do not open or attempt to repair the machine.
e detector has an internal high voltage supply
that can generate more than 2,500V.
Vinyl Tubing Set (3ft x 3)!
• From sample to drying tube
• From drying tube to RAD7 inlet
• From RAD7 outlet to exhaust
USB/Serial Supplies!
• USB to serial adaptor cable
• Adaptor cable documentation
• Adaptor cable software driver CD
RAD7 Documentation Package!
• RAD7 User’s Manual
• Additional documentation
Section 1 Getting Started
12

e batteries are Gates Monobloc type 0819-0012,
6V 2.5Ah. ere are two installed in the
instrument. ey are not user replaceable.
1.2.1 Air Travel
It is safe to take the RAD7 on an airplane either as
carry-on or checked baggage. It is probably
easiest, and least likely to cause problems, if it is
put inside a suitcase, with clothes, and checked in.
However when putting the RAD7 in checked
luggage, it is very important to leave the
instrument’s air outlet open to the outside air, in
order to prevent a pressure difference from
occurring between the inside and outside of the
instrument.
Some airlines and some airline staffare concerned
about lead-technology batteries, such as those in
the RAD7. An MSDS sheet, issued by the battery
manufacturer, is enclosed with the manual in the
RAD7 documentation. A copy of that should be
carried and presented when requested, when
traveling with a RAD7 by air.
1.3 Taking a Look
The RAD7 Professional Electronic Radon Detector
Section 1 Getting Started
13

1.4 Starting a Two-day Test
You will need the RAD7 and power cord, the
Laboratory Drying Unit (the large tube of
desiccant, with a screw cap at one end), an inlet
filter (one of the six small filters supplied), the
piece of tubing with a 5/16” ID segment at one
end and a ⅛” ID segment at the other and the
printer.
On first starting up, you may need to set the clock
for your time zone (See Setup Clock, Chapter
2.4.11). Switch on the RAD7, push [MENU], then
push [➔]twice. You will see Setup on the
display. Push [ENTER], then push [➔]ten
times. You will see Setup Clock. Push [ENTER].
Use the arrow keys to adjust hours, minutes,
seconds, day, month and year, pushing [ENTER]
to confirm each setting. Now we are ready to
continue.
RAD7 Normal Configuration
Attach the filter to the tubing (push it into the end
with the insert).
Carefully remove both plastic caps from the
Drying Unit (you will need them later, to reseal
the unit). Attach the sleeved end of the tubing to
the tube fitting, on the Drying Unit, farthest from
the screw cap.
Attach the filter to the Inlet port of the RAD7. e
air sampling system is now set up for the
measurement. (See RAD7 Standard Configuration
diagram at le.)
Plug in the RAD7 and switch on.
Push [MENU], [ENTER], then push [➔]four
times. You should see on the LCD display:
Test Purge.
Push [ENTER]. e pump should start.
Set up the printer (insert paper and batteries - see
manual).
Place printer between green lines on face plate
(See photo, Chapter 1.3).
Aer purging for some time (normally, at least five
minutes), push [MENU], and [➔]two times, you
will see: Setup on the display.
Push [ENTER] twice, then push either arrow key
repeatedly until you see:
Protocol: 2-Day on the display. Push [ENTER].
With Setup on the display, push [ENTER], then
[➔]seven times, to see >Setup Format on the
display. Push [ENTER] then use arrow keys to
select Format: Short. Push [ENTER].
Switch offthe RAD7. Switch on the printer, now
switch the RAD7 back on. e printer will print
out something like the following:
DURRIDGE RAD7
Vers 3.1a 151208
Model 716
Serial 00512
Calib 21-MAY-17
Last used
FRI 21-MAY-17 17:30
Current settings
FRI 21-MAY-17 19:09
Section 1 Getting Started
14

Protocol: 2-Day
Cycle: 01:00
Recycle: 48
Mode: Auto
Thoron: Off
Pump: Auto
Tone: Geiger
Format: Short
Units: pCi/L °C
m) Push [MENU], [ENTER], [➔]. You
should see on the LCD display: >Test Start
n) Push [ENTER]. e pump will start
running. On the LCD display you will see
something like:
0101 Live Sniff
00:59:37 00001
You are now monitoring the radon level right
where you are. Every hour, the printer will print
out a reading something like this:
0102 2.69 " 0.73 p Sniff
FRI 21-MAY-13 19:41
26.8 C RH: 7% B:7.06V
Where 0102 are the run (01) and cycle (02)
numbers, 2.69 is the measured radon
concentration, 0.73 is the two-sigma
STATISTICAL uncertainty, p indicates the units
(in this case pCi/L), and Sniffshows that, for this
reading, only the Po-218 decays are being counted
(aer three hours, the mode changes automatically
to Normal). e second line is clearly the date
and time, while the third shows the temperature
and humidity inside the measurement chamber,
and the battery voltage. Medium and Long format
settings print more information each cycle.
If you allow the RAD7 to complete a run, it will
print out a summary of the entire run, including:
1. Date and time
2. Machine serial number
3. Average value for the test
4. Bar chart of the individual readings, and
5. Cumulative alpha energy spectrum.
In the example shown it may be seen that the
average level was 3.71 pCi/L, or 137 Bq/m3.
To terminate the run early, you may switch offthe
RAD7. e data collected, to the end of the last
completed cycle, is automatically stored in the
RAD7 memory, and available for later display,
printing or download to a PC. If you wish to store
the last, incomplete cycle data as well, use Test
Save before switching offthe RAD7. When you
do this, the end-of-run printout does not take
place. e summary is stored in memory and may
be printed at any time, except that the cumulative
spectrum, which would have been printed out at
the end of the run, is lost.
End-of-Run Printout
Section 1 Getting Started
15

1.5 Starting a SniffTest
Sniffing lets you make quick, qualitative surveys of
radon and thoron levels. It may be used to search
for radon entry points. ere are some advantages
in sniffing for both thoron and radon at the same
time, (see Chapter 3.13.3), so that is the procedure
described here.
You will need the same equipment as for the 2-day
test, above, except that a small drying tube should
be used, instead of the laboratory drying unit.
Also, for portability, you may remove the external
power from the RAD7, and run the RAD7 on its
batteries.
If you have not already done so, set the clock, as
described above.
RAD7 SNIFF Configuration
a) Attach the filter to the tubing (push it into the
end with the ⅛” ID segment)
b) Carefully remove both plastic caps from the
small drying tube (you will need them later, to
reseal the unit). Attach the 5/16” ID end of the
tubing to one end of the tube.
c) Attach the filter to the Inlet port of the RAD7.
Make sure it is firmly fit onto the inlet. e air
sampling system is now set up for the
measurement. While testing, you can use the
small drying tube as a wand, to collect your air
sample from the location of interest.
d) Plug in the RAD7 and switch on.
e) Push [MENU], [ENTER], then push [➔]four
times. You should see on the LCD display: Test
Purge.
f) Push [ENTER]. e pump should start.
g) Set up the printer.
h) Place printer between green lines on the face
plate (See photo, Chapter 1.3).
i) Aer purging for a few minutes push [MENU],
and [➔]two times, you will see: >Setup on
the display.
j) Push [ENTER] twice, then push either arrow
key repeatedly until you see:
Protocol: Thoron on the display. Push
[ENTER]. (See Chapter 2.4.5 for difference
between oron and Sniffprotocols).
k) With Setup on the display, push [ENTER],
then [➔]seven times, to see Setup Format on
the display. Push [ENTER] then use arrow
keys to select Format: Short. Push
[ENTER].
l) Switch offthe RAD7. Switch on the printer,
now switch the RAD7 back on. e printer
will print out something like the following:
Section 1 Getting Started
16

DURRIDGE RAD7
Vers 3.1a 151208
Model 716
Serial 00512
Calib 21-MAY-17
Last used
WED 23-MAY-17 17:30
Current settings
FRI 25-MAY-17 19:09
Protocol: Thoron
Cycle: 00:05
Recycle: 00
Mode: Sniff
Thoron: On
Pump: Auto
Tone: Geiger
Format: Short
Units: pCi/L °C
m) Push [MENU], [ENTER], [➔]. You should see
on the LCD display: >Test Start
n) Push [ENTER]. e pump will start running.
On the LCD display you will see something
like:
0201 Live Sniff
00:04:37 00001
You are now sniffing for thoron and radon. Every
five minutes, the printer will print out a reading
something like this:
0203 2.69 ± 2.83 p Sniff
1.68 ± 2.15 p Thoron
FRI 21-MAY-17 19:41
26.8 °C RH: 7% B:7.06V
Where 0203 are the run (02) and cycle (03)
numbers, 2.69 is the measured radon
concentration, 2.83 is the two-sigma
STATISTICAL uncertainty, p indicates the units
(in this case pCi/L), and Sniffshows that, for this
reading, only the Po-218 decays are being
counted. e second line is the measured thoron
concentration and uncertainty. e third line is
now the date and time, while the fourth shows the
temperature and humidity inside the
measurement chamber, and the battery voltage.
Medium and Long format settings print more
information each cycle.
Note that the Po-218 has a 3-minute half life.
Aer moving to a new location, it will take about
15 minutes for the count rate to reach equilibrium
with the new radon concentration. So not until
aer the third 5-minute cycle will the reading
indicate the new level. However, the thoron
daughter, Po-216, has a very short half life (150
ms), so the response of the RAD7 to thoron is
virtually instantaneous. For thoron, the first 5-
minute cycle is as good as any other.
oron will only be found very close to radon
entry points. at, together with its fast response,
makes thoron sniffing an excellent sleuth for
radon entry points.
To terminate the run any time, you may switch off
the RAD7. e data collected, of completed
cycles, is stored in the RAD7 memory, and
available for later display, printing or downloading
to a computer.
Section 1 Getting Started
17

2 BASICS OF RAD7 OPERATION
2.1 Introduction
2.1.1 The Keypad
e RAD7 is operated through a four-key menu-
driven interface. ese four keys allow you to
look at the commands, select one, and then do it.
Menu Key
Press [MENU] and you see the menu prompt (>)
and the word Test:
>Test
Arrow Keys
Press the forward and backward arrow keys to go
through the available options. To advance quickly
through the options, hold down the key so that it
"auto-repeats."
e arrow keys allow you to move right and le
through the various commands, looking for the
action you want.
Enter Key
When you have decided on a certain menu option,
you select it by pressing [ENTER]. e enter key
tells the RAD7 that you have made your selection.
You are telling it what you want it to do.
e enter key makes it happen.
2.1.2 Command List
e RAD7 command list has four command
groups: Test, Data, Setup and Special. e Test
group of commands controls the collection of new
radon data. e Data group retrieves data from
memory, outputs them, and gets rid of old,
unwanted data. e Setup group prepares the
RAD7 to operate according to your requirements.
e Special group is a set of commands that are
available when RADLINK, the remote control
soware, is loaded.
2.2 Test
e Test group of commands controls the
collection of radon data and allows you to
manipulate the current test (test-in-progress). You
can start and stop data collection, save or clear the
current test, or print the current test as it stands.
(e Test commands do not allow access to stored
data. You have to go to Data for that.)
2.2.1 Test Status
To see the status display, enter the Test Status
command. Press [MENU], [ENTER], [ENTER]
On the LCD display, you will see:
0501 Idle Sniff
00:30:00 00000
On the upper le, you see the current run
number/cycle number (0501 - run 05, cycle 01.).
e middle shows the detector status (Idle or
Live), and the upper right gives the current test
mode (Sniff, Normal or Grab). (Note that in
AUTO mode, the indication will change from
Sniffto Normal aer three hours of measurement.
Lower leshows the count-down timer (00:30:00
= 30 minutes) which counts down to zero when
the detector is Live (i.e., a test is in progress). e
lower right shows the total number of counts since
the beginning of the current cycle.
e arrow keys may now be used to access
additional status information.
Press [➔]once, and you will see something like
this:
Last reading:
0409 1.80 " 0.74 p
e lower leis the run number (2 digits) and
cycle number (2 digits) of the last completed cycle
stored to memory.
e lower right is the radon reading and two-
sigma statistical uncertainty, followed by “p”,
Section 2 Basics of RAD7 Operation
18

indicating picoCuries/liter, or "b" for Becquerels/
cubic meter.
When a cycle ends, the information on this
display is updated. If there have been no readings
yet, the display will show
No readings yet.
Press [➔]once again, and now you will see
something like this:
24.8°C RH:3%
B: 6.36V P: 00mA
Top leis the internal temperature. (To change
from Celsius to Fahrenheit, see Chapter 2.4.9,
Setup Units.)
Top right shows the internal Relative Humidity
reading. When testing, maintain this value at 10%
or less, by using the desiccant.
Bottom leis the battery voltage. is should
range from about 6.00V to 7.10V. A discharged
battery (less than 6.00 ) should be recharged as
soon as possible. A fully charged battery will rest
at 6.40 to 6.50 V. During a recharge, the voltage
will eventually rise above 7.00 V. At no time
should this read higher than 7.20V. In the lower
right is the pump current. is number should
vary from 00mA (pump off) to 80mA. When the
pump is running with a light load, the current will
range from 40-70mA. When the pump is running
with a heavy load (clogged filter or blocked hose),
the current will go to 90mA or higher. Pump
currents above 90mA are considered a sign of
trouble. Try changing the filters and check for
blockage.
Press [➔]again, and you will see something like
this:
HV: 2218V, 10%
L: 02 S: 0.21V
is is a display of diagnostic values. Ordinarily it
will be of little interest to you.
e top line is the high voltage reading and High
Voltage Duty Cycle. e range of normal values is
from 2000 to 2500V, and from 8% to 18%,
respectively.
e lower lecorner is the leakage current. At
room temperature, this value will normally range
from 0 to 10. Higher temperatures ordinarily
cause this value to rise. Excessive leakage current
will result in "noise" in the lower energy end of the
spectrum, and will also cause broadening of the
alpha peaks.
e lower right corner is the signal voltage from
the analog circuit. is number should be "stable";
that is, fluctuations should be no more than "
0.05V from the average value.
Press [➔]yet again, and you will see something
like this:
w | cpm | +/- | %tot
A | 6.0 | 4.3 | 48.8
is is the display for the A window data. You
may press [➔]to advance to B, C, D, etc.
e RAD7 records 8 windows (A - H) every time
you make a measurement. ey separate counts
due to daughters of radon and thoron, and the
background. Specific alpha particles end up in
specific windows.
W: e window letter.
cpm: e counts per minute observed in the
window.
+/-: e two-sigma statistical uncertainty of the
cpm value, also in units of cpm.
%tot: e number of counts in the window as a
percentage of the total counts in the spectrum.
is tells you quickly where the majority of the
counts are: In the 3-minute radon peak (window
A), or the long-lived radon peak (window C), etc.
As always, you press the [MENU] key to exit this
display and return to the start of the menu.
2.2.1a Quick Save-and-Restart
is function allows the user to end a snifftest,
store it to memory, and start up a new snifftest, all
using a single key. It operates only from the
SNIFF mode.
Section 2 Basics of RAD7 Operation
19

From the status display (showing the countdown
timer), press the [ENTER] key once. e display
will show:
Save and restart
? Yes
Press the [ENTER] key once more to confirm your
intention. To escape, push the [MENU] key or
push an arrow key to select “No” and push
[ENTER].
2.2.2 Test Start and Test Stop
To start testing (or "counting"), aer you have
chosen the required setup, go to >Test Start by
pressing [MENU], [ENTER], [➔], and then
[ENTER]. e display will indicate that counting
has begun:
Start counting.
One second later, the Status display will appear
with the countdown timer in motion:
0501 Live Sniff
00:29:37 00001
When the countdown reaches zero, the RAD7 will
automatically calculate the radon concentration,
store (or "save") the counts to memory, and clear
the counters to begin a new cycle.
To interrupt the measurement, go to >Test
Stop
by pressing [MENU], [ENTER], [➔], [ENTER].
e display will respond:
Stop counting.
Aer one second, the display will go back to the
top of the menu >Test.
You may wish to examine the Status display to
verify that the status is Idle.
To resume testing from exactly the same point in
the cycle where you stopped, select >Test Start
as described above.
Note that Stop does not terminate the run, it is a
pause. If you do not wish to resume testing from
the same point, you should select either >Test
Save or >Test Clear before continuing. is
will terminate the suspended test, store it to
memory (Save) or wipe it out (Clear), and clear
the counters to begin a new run.
2.2.3 Test Save
e >Test Save command suspends counting
and saves the suspended test (test-in-progress) to
memory as if it had reached completion. Test Save
completes the current run, so any subsequent test
data will be stored as a new run. e display
momentarily shows the run and cycle number in
the form of 0101 Saved. is command may be
accessed whether the status is Live or Idle. It
always leaves the status Idle.
You will find this command especially useful when
you wish to move the instrument to another
location without waiting for the countdown to
reach zero, but without losing that last incomplete
cycle. e calculated radon concentration from
the incomplete cycle is still good.
2.2.4 Test Clear
e >Test Clear command causes counting to
be suspended and the current run to be completed
without saving the last (suspended) incomplete
cycle. Subsequent test data will be stored as a new
run. You must answer Yes to the question Are you
sure? in order to activate this command.
is command may be accessed whether the
status is Live or Idle. It always leaves the status
Idle.
2.2.5 Test Purge
e>Test Purge command suspends counting
and begins purging the detector. e pump
begins running and the high voltage circuit turns
offin order to clear the sample chamber of radon
gas and daughters as quickly as possible. You
must provide clean, desiccated, radon-free air to
the inlet in order to push out any radon that was
previously sampled. Outdoor air is usually
adequate for this purpose.
As always, use the inlet filter and drying tube. Ten
minutes is usually sufficient for bringing the
Section 2 Basics of RAD7 Operation
20