Radiation Alert INSPECTOR+, INSPECTOR-EXP+ Instruction Manual

RADIATION ALERT

®

User Manual

Manuel d’instructions Page 31
Manual de Instrucciones Page 60

&

+

+

EXP

06/1/05

Inspector+ User Manual - Contents

Chapter Page

1 Introduction 4

How the Inspector+ Detects Radiation 4
Precautions 4

2 Features 5

The Display 6
The Switches 7
The Detector 8
The Input/Output Ports 9

3 Operation 10

Units of Measurement 10
Starting the Inspector+ 10

Start Up 10
Display Update 10
Maximum Level 10

Response Time (Autoaveraging) 10
Operating in Dose Rate Modes 11
Operating in Total/Timer Mode 11

Taking a Timed Count 12

Using Dose Rates While Timer is On 13

Taking a Total Count 13
Autoranging 13
Using the Alert 14
Utility Menu 14
Interfacing to an External Device 15
Options 16

06/18/03

WipeTest Plate 16

4 Common Procedures 16

Establishing the Background Count 16
Environmental Area Monitoring 16
Checking for Surface Contamination 17

Maintenance 17

Calibration 17
Troubleshooting 20
Service 21

6 Basics of Radiation and Its Measurement 22

Ionizing Radiation 23
Chart of Radionuclides 23

Radiation Measurement Units 23
Appendix A Technical Specifications 24
Appendix B Sensitivity to Common Isotopes 25
Appendix C Inspector+ EXP carrying case 26
Warranty 28
Calibration Data Base Application 29

List of Illustrations

Figure 1 Front View 5
Figure 2 End Panel View 6
Figure 3 Display 6
Figure 4 Rear View (Detector) 9

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1 Introduction

The Inspector+ is a health and safety instrument that is optimized to detect low
levels of radiation. It measures alpha, beta, gamma, and x-ray radiation.

Its applications include:

• Detecting and measuring surface contamination

• Monitoring possible radiation exposure while working with radionuclides

• Screening for environmental contamination

• Detecting noble gases and other low energy radionuclides

How the Inspector+ Detects Radiation

The Inspector+ uses a Geiger-Mueller tube to detect radiation. The Geiger tube
generates a pulse of electrical current each time radiation passes through the
tube and causes ionization. Each pulse is electronically detected and registers as
a count. The Inspector+ displays the counts in the mode you choose.

The number of counts detected by the Inspector+ varies from minute to minute
due to the random nature of radioactivity. A reading is expressed more accurately
as an average over time, and the average is more accurate over a longer time
period. For details, see “Operating in Total/Timer Mode” in Chapter 3.

Precautions

To keep the Inspector+ in good condition, handle it with care, and observe the
following precautions:

• Do not contaminate the Inspector+ by touching it to radioactive surfaces
or materials. If contamination is suspected, replacement rubber strips are
stapled inside this manual.

• Do not leave the Inspector+ in temperatures over 100° F (38° C) or in
direct sunlight for extended periods of time.

• Do not get the Inspector+ wet. Water can damage the circuitry and the
mica surface of the Geiger tube.

• Do not put the Inspector+ in a microwave oven. It cannot measure
microwaves, and you may damage it or the oven.

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• This instrument may be sensitive to and may not operate properly in radio
frequency, microwave, electrostatic, and electromagnetic fields.

• If you expect to not use the Inspector+ for longer than one month, remove
the battery to avoid damage from battery corrosion.

• Change the battery promptly when the battery indicator appears on the
display.

2 Features

The Inspector+ measures alpha, beta, gamma, and x-ray radiation. It is optimized
to detect small changes in radiation levels and to have high sensitivity to many
common radionuclides. For more information, see Appendix A, “Sensitivity to
Common Radionuclides.”

This chapter briefly describes the Inspector+’s functions. For more information on
how to use the Inspector+, see Chapter 3, “Operation.”

The Inspector+ counts ionizing events and displays the results on the liquid crystal
display (LCD). You control which unit of measurement is shown by using the
mode switch.

Whenever the Inspector+ is operating, the red count light (8) flashes each time a
count (an ionizing event) is detected.

(1) LCD Display

(9) CAL Input

(8) Count Light

(7) Tube Center

Indicator

(3) On/Off/Audio

Switch

(2) Mode Switch

(10) Output

Figure 1 Front View

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Figure 2 End Panel View

The Display (1)

The LCD (liquid crystal display) shows various indicators according to the mode
setting, function being performed, and battery condition.

Figure 3 Display Indicators

INDICATORS:

• The numeric display (A) shows the current radiation level in the unit

specified by the mode switch setting.

• A small battery (B) appears to the left of the numeric display indicating

low battery voltage.

•ARadiation Symbol (C) Appears to the left of the numeric display when

the Alert mode is activated.

• An hourglass (D) appears to the left of the numeric display while in the

Cal mode or during a timed count.

(A) Numeric Display

(B) Low Battery

(C) Alert

(D) Timer

(E) Total

Mode

(I) Units of

Measurments

(H) Utility Menu, Timer,

Calibation, Alarm

Set Mode

(G) CAL

Mode

(F) X1000

Mode

(4) Timer Switch

(6) Plus & Minus Buttons

(5) Set Button

GM Center Inticator

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• TOTAL (E) appears when the Inspector+ is in Total/Timer mode.

• X1000 (F) appears when the numeric display is to be multiplied by 1000.

• CAL (G) is shown while you are calibrating the Inspector+.

• SET (H) appears when you are setting the timer (the numeric display

shows the timed period instead of the current radiation level), in the
Cal mode (the numeric display shows the Cal factor instead of the current
radiation level), and while adjusting settings in the Utility and Alarm
Menus.

• The current unit of measurement (I)—CPM, CPS, mR/hr or µµSv/hr—is

displayed to the right of the numeric display.

The Switches

The Inspector+ has two switches on the front, and one switch and three buttons
on the end panel. Each switch has three settings which are described below.

Mode Switch (Figure 1(2))

mR/hr µµSv/hr. The numeric display shows the current radiation level in
milliroentgens per hour or, when SI units are used, in microsieverts per hour.

In mR/hr mode, the Inspector+ displays the radiation level from .001 to 100.
In µSv/hr mode, the Inspector+ displays the radiation level from .01 to 1000.

See “Utility Menu” in Chapter 3 for details on how to activate this mode.
CPM CPS. In CPM, the display shows the current radiation level in counts

per minute from 0 to 300,000. When X1000 is shown on the display, multiply
the numeric reading by 1000 to get the complete radiation level. When using
SI units, the display shows the radiation level in counts per second from 0 to

5000.
Total/Timer. The display shows the accumulated total of counts from 1 to

9,999,000. When X1000 is shown on the display, multiply the numeric
reading by 1000 to get the complete radiation level. Totaling starts when the
switch is moved to this position. For details, see “Taking a Timed or Total
Count” in Chapter 3.

Off/On/Audio Switch (Figure 1 (3))

Audio. The Inspector+ is on and makes a clicking sound for each

radiation event detected.

On. The Inspector+ is operating, but audio is off.

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Off. The Inspector+ is not operating.

Timer Switch (Figure 2 (4))

Off. The timer is not operating.
Set. The length of the timed period can now be set using the “+” and

“-” buttons. If the timer is already operating, the display shows
the time remaining in the timed period.

On. The timer is operating, and the display shows the total counts

accumulated so far in the timed period.

Set Button (Figure 2 (5))

The Set button is used to set the alert, select items in the Utility Menu, and
set the Calibration settings. See “Using the Alert” and “Utility Menu” in
Chapter 3 and “Calibration” in Chapter 5.

+ and - Buttons (Figure 2 (6))

The “+” and “-” buttons are used to adjust the numeric display for timed
counts, alert settings, and calibration settings. See “Taking a Timed Count”
and “Setting the Alert” in Chapter 3 and “Calibration” in Chapter 5.

The “+” and “-” buttons can also be used to make selections in the “Utility
Menu”. For details, see “Utility Menu” in Chapter 3.

The Detector

CAUTION: The mica surface of the Geiger tube is fragile. Be careful not to let

anything penetrate the screen.

Internal- For Inspector+ only

The Inspector+ uses a two-inch Geiger tube, commonly called a “pancake tube.”
On the back of the Inspector+, the screen is called the window. See Figure 4. It
allows alpha and low-energy beta and gamma radiation, which cannot get through
the plastic case, to penetrate the mica surface of the tube. The small radiation
symbol (Figure 1 (7)) on the front label indicates the center of the Geiger tube .

External - For Inspector+ EXP only

The Inspector+ EXP has an external pancake probe instead of the built-in
detector. To connect the detector, plug one end of the cable into the connector on

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the end panel and the other end to the probe. Caution: If the probe is not

connected when turning the instrument on, the instrument will not function
properly and may cause damage. Do no remove the probe while the

instrument is on.

Figure 4 Inspector+ Rear View (Detector)

The Input/Output Ports

The Cal Input (Figure 1 (9)) port is used for calibrating electronically using a
pulse generator. For details, see “Calibrating Electronically” in Chapter 5.

The Output (Figure 1 (10) port below the Cal Input jack allows you to interface
the Inspector+ to a computer, data logger, or other device. For details, see
“Interfacing to an External Device” in Chapter 3.

The probe port on the end panel is for attaching the external probe. (present on
Inspector+ EXP only)

GM Detector
Window

Battery
Compartment

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3 Operation

Units of Measurement

The Inspector+ is designed for use of conventional units (milliroentgens per hour
and counts per minute) or SI units (microsieverts per hour and counts per
second). To switch between conventional or SI units choose Option 2 in the Utility
Menu. For details, see “Utility Menu” in Chapter 3.

Starting the Inspector+

Before starting the Inspector+, install a standard 9-volt alkaline battery in the
battery compartment in the lower rear. Note: Place the battery against the
bottom wall and make sure the wires are placed along the side of the battery and
not under it.

Start Up. To start the Inspector+, set the top switch to the mode you want, and
set the bottom switch to On or Audio. The Inspector+ then begins a 6-second
system check. All indicators and numbers are displayed.

After the system check, the radiation level is displayed in the selected mode.
Approximately thirty seconds after you start the Inspector+, a short beep indicates
that enough information has been collected to ensure statistical validity

.

Display update. In the dose rate modes, the numeric display is updated every
three seconds. In Total/Timer mode, the numeric display is updated twice a
second.

Maximum level. When the maximum level for the current mode is reached, the
Inspector+ beeps for three seconds, pauses for three seconds, and repeats that
pattern. The numeric display flashes. The beeping pattern and the flashing
display continue until the level decreases or the Inspector+ is turned off.

Response Time (Autoaveraging). When the radiation level is less than 6,000
CPM, the reading in any of the dose rate modes is based on the radiation
detected in the immediately previous 30 seconds. In order to give a quicker
response to changes, when the radiation level exceeds 6,000 CPM in any 30
second period, the reading is based on the previous 6 seconds. When the
radiation level exceeds 12,000 CPM in any 30-second period, the reading is

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based on the previous 3 seconds. Note: You can choose the 3 second response
at any radiation level by using the Utility Menu detailed in Chapter 3. Refer to the
following table.

After 30 second start-up the reading will be based
if instrument is detecting on an average of the previous

(<100 CPS) 30 seconds
< 6000 CPM or <1.75 mR/hr

(100 -200 CPS) 6 seconds
6000-12,000 CPM or 1.75-3.6 mR/hr

(>200 CPS) 3 seconds fast response
>12,000 CPM or >3.6 mR/hr

Autoranging

When radiation levels increases in some modes over certain preset levels, the
Inspector+ uses autoranging, automatically changing to the X1000 scale.
Whenever X1000 is shown above the numeric display, multiply the displayed
reading by 1000 to determine the radiation level. mR/hr, µSv/hr and CPS are not
applicable.

Mode Ranges as they are displayed

CPM 0 to 2,999 CPM > 2,999

X1000

3.000 (3,000) CPM to 350 (350,000) CPM

Total/Timer 0-9,999 counts > 9,999

X1000

10.00 (10,000) to 9999 (9,999,000) counts

Operating in Dose Rate Modes

Caution: 1. Be sure there is no obstruction between the detector window and

source being monitored/surveyed. 2. Avoid making measurements
with the GM window facing the sun, it could affect your readings.

When the mode switch is set to mR/hr µµSv/hr or CPM CPS, the numeric display
is updated every three seconds. At low count rates, significant changes in the

radiation level displayed can take up to 30 seconds to stabilize. For details, see
“Autoranging” in this chapter.

CPM (or CPS) and total counts are the most direct methods of measurement;
mR/hr (or µSv/hr) is calculated using a conversion factor optimized for Cesium-

137. This mode is less accurate for other radionuclides unless you have
calibrated the Inspector+ for a similar radionuclide.

The most immediate indicators of the radiation level are the audio and count light.
It takes 3 seconds before a change is shown on the numeric display unless you
are using the Total/Timer mode.

Operating in Total/Timer Mode

When the mode switch is set to Total/Timer, the numeric display is updated twice
a second and totaling starts.

Taking a Timed Count

When a timed count is taken over a longer period, the average count per minute
is more accurate, and any small increase is more significant. For example, if one
10-minute average is one count higher than another 10-minute average, the
increase may be due to normal variation. But over 12 hours, a one-count
increase over the 12-hour background average may be statistically significant.

The Inspector+ can give you a total count for a timed period from 1 minute to 24
hours. For a timed count of less than one minute, watch the seconds countdown
on the display. You can manually shut off the timer at any point.

Follow these steps to take a timed count:

1. With the Inspector+ turned on, set the Mode switch to Total/Timer and the
timer switch on the end panel to Set. The timer Hourglass and the SET icon
appear on the display and the value is set to 00:01(1 minute).

2. Use the “+” and “-” buttons to adjust the timing period. The timed period can
be set for 1 to 10 minutes in one-minute increments, for 10 to 50 minutes in
ten-minute increment

s, or for 1 to 24 hours in one-hour increments.

3. Set the Timer switch to On. The Inspector+ beeps three times and starts
counting. The hourglass icon flashes during the timed period.

If you want to see how many minutes remain, set the Timer switch to Set.

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13

The display counts down from the time setting in hours and minutes to zero.
For example, if the display says 00:21, 21 minutes remain. During the timed
period, you can switch back and forth between Total/Timer and the dose
rate modes without interrupting the timed period. The hourglass indicator will
show in any mode setting and will blink while the timer is totaling.

4. At the end of the timed period, the Inspector+ beeps three times, and repeats
the beeping several times over fifteen seconds. The number displayed is the
total count.

5. Set the Timer switch to Off to return to normal operation.

To find the average counts per minute for the timed period, divide the total by the
number of minutes.

6. To reset the timer to take another timed count, move the timer switch to the
Off position and then to the On position. The instrument will retain the timer
setting of the last entered time.

Using Dose Rate Modes While Timer is On

Dose rate modes can be used while the timer is on. In any dose rate mode, the
hour glass indicator will continue to flash during a timed period. At the end of the
timed period, the hour glass will remain continuously on and the timed reading is
held in the Total/ Timer mode.

Taking a Total Count

The timer can take timed counts of up to twenty-four hours. In certain situations,
you may want to take a total count without the timer; for example, taking a count
for longer than twenty-four hours. Follow these steps:

1. Place the Inspector+ in the location where you plan to take the count.

2. Note the time.

3. Immediately when you note the time, set the mode switch to Total/Timer.

4. At the end of the time period, note the time and the number of counts on the
numeric display.

5. Subtract the starting time from the ending time to determine the exact
number of minutes in the timing period.

6. To get the average count, divide the total counts by the number of minutes in

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the timing period.

Using The Alert

The Alert can be set in mR/hr or cpm. Once the alert threshold is reached the
beeper will sound until the alert is deactivated, or the radiation level drops below
the set alert threshold.

1. To set the Alert, press the "SET" button on the end panel. The "ALERT" icon
(radiation symbol) and the "SET" icon are displayed.

2. Use the "+" and "-" buttons to adjust the display to the desired level.

3. Press the "Set" button once to retain the setting in memory. Then press it
again to turn the alert mode on. The "ALERT" icon is now displayed to
indicate the instrument is operating in the Alert mode.

4. To use the previous alert setting, press the set button twice. Now the alert
mode is on.

5. To deactivate the Alert mode, press the "Set" button again. The "ALERT" icon
is no longer displayed.

Utility Menu

The Utility Menu allows the user to change default settings for several operating
parameters. Once a setting is changed, it remains in effect unless they are
changed through the Utility Menu.

1. To activate the Utility Menu, hold down the “+” button while turning the

instrument on. The display will show the "MENU" icon. Release the “+” button

and a “1” indicating option 1 will appear along with the “Menu” icon.

2. Scroll through the menu by pushing the “+” or “-” buttons.

3. To select an option, push the “Set” button and the “SET” icon is displayed.

4. Use the “+” or “-” buttons to toggle between choices and press the “Set” button
to enter the new value. The instrument will continue to operate in the Utility
Menu mode, and the display will show "0" and "MENU". To adjust another
Utility Menu option, repeat the above steps.

5. To exit the Utility Menu at any time, press the SET button again. The
Inspector+ continues with the normal start-up routine. See options in the table

below:

Options Function Comments

1. Auto Averaging or “on” selects Auto Averaging Refer to
3 sec. Averaging “oFF” selects 3 second “Response Time

(fast response) averaging (Autoaveraging)” in

Chapter 3

2. Units Of Selects between mR/hr
Measurements and CPM or µSv and CPS

3. Cal 100 Reset Automatically resets Cal Press the set Button

factor to 100 No toggling required

4, 5, 6 Reserved for future options

7. Cal Factor Adjust Manually adjusts cal factor Use + or - Buttons

to increase or
decrease the value

8. Factory Default Automatically resets to Press the set Button
Reset Auto Averaging, mR/hr, CPM, No toggling required

and CAL 100

9. Revision # Displays software version number

Interfacing to an External Device

The lower output jack (Figure 1 (10)) on the left side of the Inspector+ is a dual
miniature jack that provides a data output that can be used to drive a CMOS or
TTL device. You can use it to record the counts on a computer, data logger, or
accumulating counter. The output at the tip of the plug provides a positive (5 volt)
pulse each time the Geiger tube detects a count. Visit seintl.com for more
information on Observer Software.

Options

Wipe T est Plate (p atent # 5,936,246)

The stainless steel WipeTest Plate has a circular depression for placement of a

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wipe parallel to the detector window at a fixed distance of 1 cm. The WipeTest
Plate is designed to slide easily onto the back of the Inspector+.

4 Common Procedures

The following sections give instructions for several commonly-used procedures.
With any procedure, the user must determine the suitability of the instrument or
procedure for that application.

Establishing the Background Count

Normal background radiation levels vary at different locations, time, even in
different areas of the same room. To accurately interpret the readings you get on
the Inspector+, it is good to establish the normal background radiation count rate
for each area you plan to monitor. You can do this by taking a timed count. For
more information on using the timer, see “Taking a Timed Count” in Chapter 3.

A ten-minute average is moderately accurate. You can repeat it several times and
see how close the averages are. To establish a more accurate average, take a
one-hour timed count. If you need to determine whether there is prior
contamination, take averages in several locations and compare the averages.

Environmental Area Monitoring

You can keep the Inspector+ in CPM or mR/hr mode whenever you want to
monitor the ambient radiation, and look at it from time to time to check for
elevated readings.

If you suspect an increase in ambient radiation, use the timer and take a five or
ten minute count, and compare the average to your average background count. If
you suspect an increase that is too small to detect with a short timed reading, you
can take a longer count (for example 6, 12, or 24 hours).

Checking for Surface Contamination

CAUTION: Never touch the Inspector+ to a surface that may be contaminated.

You may contaminate the instrument. The rubber strips on the back
can be replaced if they become contaminated. Replacement strips
are supplied in this manual.

17

To check a surface, hold the detector window close to the surface and read the
count rate (wait 30 seconds or until the reading has stabilized). If you want to find
out if a surface is slightly radioactive, take a timed count or a longer accumulated
count.

5 Maintenance

The Inspector+ requires regular calibration and careful handling to assure good
measurements. Use the following guidelines to maintain the Inspector+ properly.

Calibration

The Inspector+ should be calibrated as often as your regulations require, or in any
case, at least once a year. The best way to calibrate is using a calibrated source.
If no source is available, it is possible to calibrate electronically using a pulse
generator.

The standard radionuclide for calibration is Cesium-137. A certified calibration
source should be used. To calibrate the Inspector+ for another radionuclide, you
must use a calibrated source for that radionuclide or the appropriate conversion
factor referenced to Cs-137.

CAUTION: Errors can occur when using low level sources or background to set
CAL factor. In the Calibration mode, the smallest increment which can be
adjusted is .010, which prevents fine adjustment of the CAL factor.

Calibrating Using a Source

1. Place the Inspector+ or Inspector+ EXP probe at a distance from the source
that corresponds to a 50 mR/hr field with the detector window facing the
source.

2. Set the Inspector+ mode switch to mR/hr.

3. Turn the Inspector+ on.

4. Open the source and record 20 consecutive readings.

5. Close the source.

6. Calculate the average of the readings and record.
a) If the average is ± 10% of 50 mR/hr, go to Step 7.
b) If the average is not ± 10% of 50 mR/hr, go to Step 10.

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7. Place the Inspector+ or the Inspector+ EXP probe at a distance from the
source that corresponds to a 5 mR/hr field with the detector window facing
the source.

8. Repeat Steps 2 - 5.

9. Calculate the average of the readings and record.
a) If the average is ± 10% of 5 mR/hr, the calibration procedure is complete.
b) If the average is not ± 10% of 5 mR/hr, go to Step 10.

10. Turn off the AUDIO in order to hear the count down timer sound.

11. Turn off the Inspector+. Hold down the “-” button on the end panel and turn
on the Inspector+. The display shows CAL, and the Inspector+ counts down
for 15 seconds, chirping each second. This delay gives you a chance to
move out of the field and then expose the source. At the end of the 15
seconds, the Inspector+ beeps.

12. The Inspector+ now collects data for 30 seconds, chirping every 2 seconds,
with CAL and the hourglass icon flashing. At the end of the 30 seconds, it
beeps. The display shows CAL and SET is flashing.

13. Close the source.

14. Press the “+” and “-” buttons on the Inspector+ to adjust the reading to what
it should be.

15. When the reading is correct, press the Set button. The new calibration factor
is displayed for several seconds, then the Inspector+ beeps and resumes
normal operation.

16. Record the new calibration factor.

17. Place the Inspector+ or the Inspector+ EXP probe at a distance from the
source that corresponds to a 5 mR/hr field with the detector window facing
the source.

18. Repeat Steps 2 - 5.

19. Calculate the average of the readings and record.|
a) If the average is ± 10% of 5 mR/hr, the calibration procedure is complete.
b) If the average is not ± 10% of 5 mR/hr, repeat steps 11 - 16 and go to
step 20.

20. Calculate the average of the calibration factor for 50 mR/hr and the
calibration factor for 5 mR/hr.

19

21. Turn the Inspector+ off. Hold down the “+” button while turning the
Inspector+ on. The numeric display will show a single number.

23. Press the “+” or “-” button until 7 is shown on the numeric display.

24. Push the Set button.

25. The calibration factor is displayed. Press the “+” or “-” buttons to adjust
the calibration factor to the average calibration factor calculated in Step 20.

26. Push the Set button to enter the new setting and resume normal operation.

The calibration factor is set to 100 (percent) at the factory. If you change the
reading, for example, to 20% higher than the factory reading, the new calibration
factor would be 120. The current calibration factor is displayed during the system
check when the Inspector+ is first turned on.

Calibrating Electronically

You can calibrate electronically using a pulse or function generator. Electronic
calibration requires a cable with a 2.5 mm plug, with the tip carrying the signal.
Follow these steps:

1. Set the signal height to 3.3 volts and a negative pulse width of 85
microseconds positive pulse.

CAUTION: Do not inject a pulse when the Inspector+ is turned off.

Do not exceed 5 volts.

2. Turn on the Inspector+ and set the mode switch to mR/hr µµSv/hr.

3. Plug the cable into the upper jack.

4. Use the following table to check the Inspector+’s accuracy. The table shows
appropriate pulse generator count rates to calibrate for Cs-137. If the
accuracy is not within desired limits, follow steps 5-7. Note that the
Inspector+ automatically compensates for lost counts due to GM tube dead
time. Thus, the display reading in CPM mode will not equal the input
frequency. You can display uncompensated counts in the CPM mode by
continuously holding down the “-” button. The reading will now correspond to
the input frequency.

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Pulse Generator CPM mR/Hr

µµ

Sv/hr CPS

Input (PPM)

31,423 33,400 10.00 100.0 557
59,335 66,800 20.00 200.0 1,113
127,043 166,999 50.00 500.0 2,783
177,752 267,200 80.00 800.0 4,453
205,031 334,000 100.0 1,000 5,567

5. Turn off the Inspector+. Hold down the ”-” button on the end panel and turn

on the Inspector+. The display shows CAL, and the Inspector+ counts down
for 15 seconds, chirping each second. At the end of the 15 seconds, the
Inspector+ beeps.

6. The Inspector+ collects data for 30 seconds, chirping every 2 seconds, with

CAL and the hourglass icon flashing. At the end of the 30 seconds, it beeps.
The display shows CAL, and SET is flashing

7. Press the “+” and “-” buttons to adjust the reading to what it should be.
When the reading is correct, press the Set button.

The new calibration factor is displayed for several seconds, then the
Inspector+ beeps and resumes normal operation.

Troubleshooting

The Inspector+ is a highly reliable instrument. If it does not seem to be working
properly, look through the following chart to see if you can identify the problem.

Problem Possible Cause What To Check

Display is blank no battery, dead battery, install a new 9-volt battery

poor battery connection if count light and audio
defective LCD work, the LCD may

need to be replaced

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Problem Possible Cause What To Check

Display works, but no defective Geiger tube or look through the window to
counts are registered bad cable check the mica surface of

the tube; if it is wrinkled or
a break is visible, replace it
check EXP cable connection

Reading is high, but contamination scan the Inspector+ (EXP)
another instrument; with another instrument
has a normal reading replace rubber strips on
in the same location back of Inspector+

Instrument has false moisture circuit board may be wet;
high reading dry the instrument in a warm

dry place; if it still has a
problem, it requires service

Instrument has false photosensitivity remove from direct sunlight
high reading and ultraviolet sources; if

the high count drops, the
mica window coating may
have washed off the Geiger
tube due to getting wet; the
tube will need to be replaced

Instrument has false continuous discharge replace the Geiger tube
high reading

Instrument has false electromagnetic field move the instrument away
high reading from possible sources of

electromagnetic or radio
frequency radiation

Service

CAUTION: Do not send a contaminated instrument for repair or calibration under

any circumstances. There are no user serviceable parts inside
instrument.

If the Inspector+ requires servicing, please contact your distributor or the

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manufacturer at the following address:
S.E. International, Inc.

P.O. Box 39, 436 Farm Rd.
Summertown, TN USA 38483-0039
Tel [phone], Fax [phone]
E-mail: [e-mail]

6 Basics of Radiation and Its Measurement

This chapter briefly tells what radiation is and how it is measured. This
information is provided for users who are not already familiar with the subject. It
is helpful in understanding how the Inspector+ works and in interpreting your
readings.

Ionizing Radiation

Ionizing radiation is radiation that changes the structure of individual atoms by
ionizing them. The ions produced in turn ionize more atoms. Substances that
produce ionizing radiation are called radioactive.

Radioactivity is a natural phenomenon. Nuclear reactions take place continuously
on the sun and all other stars. The emitted radiation travels through space, and a
small fraction reaches the Earth. Natural sources of ionizing radiation also exist in
people and in the ground. The most common of these are uranium and its decay
products.

Ionizing radiation is categorized into four types:
X-rays are manmade radiation produced by bombarding a metallic target with

electrons at a high speed in a vacuum. X-rays are electromagnetic radiation of
the same nature as light waves and radio waves, but at extremely short
wavelength, less than 0.1 billionth of a centimeter. They are also called photons.
The energy of X-rays are millions of times greater than that of light and radio
waves. Because of this high energy level, X-rays penetrate a variety of materials,
including body tissue.

Gamma rays are almost identical to X-rays. Gamma rays generally have a
shorter wavelength than X-rays. Gamma rays are very penetrating; thick lead

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shielding is generally required to stop them.
Beta radiation A beta particle consists of an electron emitted from an atom. It

has more mass and less energy than a gamma ray, so it doesn’t penetrate matter
as deeply as gamma and X-rays.

Alpha radiation An alpha particle consists of two protons and two neutrons, the
same as the nucleus of a helium atom. It generally can travel no more than 1 to 3
inches in air before stopping, and can be stopped by a piece of paper.

Decay: When an atom emits an alpha or beta particle or a gamma ray, it
becomes a different type of atom. Radioactive substances may go through
several stages of decay before they change into a stable, or non-ionizing, form.
For example; U-238 has 14 different stages of decay before it stabilizes.

An element may have several forms, or isotopes. A radioactive isotope of an
element may be called “radioisotope”. However, the more correct term is
radionuclide.

Half-life: Each radionuclide has a characteristic half-life, which is the time
required for half of a quantity of the material to decay.

Radiation Measurement Units

Several different units are used to measure radiation, exposure to it and dosage.
A roentgen is the amount of X-radiation or gamma radiation that produces one

electrostatic unit of charge in one cc of dry air at 0° C and 760 mm of mercury
atmospheric pressure. The Inspector+ displays in milliroentgens per hour
(mR/hr).

A rad is the unit of exposure to ionizing radiation equal to an energy of 100 ergs
per gram of irradiated material. This is approximately equal to 1.07 roentgen.

A rem is the dosage received from exposure to a rad. It is the number of rads
multiplied by the quality factor of the particular source of radiation. The rem and
millirem are the most commonly-used measurement units of radiation dose in the
U.S. 1 rem= 1rad.

A sievert is the standard international measurement of dose. One sievert is

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equivalent to one hundred rems. A microsievert (µSv) is one millionth of a sievert.
A curie is the amount of radioactive material that decays at the rate of 37 billion

disintegrations per second, approximately the decay rate of one gram of radium.
Microcuries (millionths of a curie) and picocuries (trillionths of a curie) are also
often used as units of measurement.

A becquerel (Bq) is equivalent to one disintegration per second.

Appendix A - Technical Specifications

Detector: Internal Halogen-quenched Geiger-Mueller tube.

Effective dia. 1.75” (45 mm).
Mica window density 1.5-2.0 mg/cm2.

External RAP-RS1 Same detector as internal. Anodized aluminum

housing with black vinyl grip. 500 volt power
supply is located in the probe head.
Connectors: Amphenol 31226 twinax.

Display: 4-Digit liquid crystal display including mode
indicators

Operating Range: mR/hr: .001 to 100.0

CPM: 0 to 350,000
Total: 1 to 9,999,000 counts
mSv/hr: .01 to 1,000
CPS: 0 to 5,000

Efficiency: Sr(Y)-90: approx. 38%; C-14: approx. 5.3%
4 p at contact P-32: approx 33%; Co-57: approx. .3%

Gamma Sensitivity:
3500 CPM/mR/hr referenced
to Cs-137

Smallest detectable level for
I-125 is .02 mCi at contact

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Averaging Periods: Display updates every 3 seconds, showing the

average for the past 30-second time period at
normal levels. The averaging period decreases
as the radiation level increases. Refer to Chapter 3

Operation- Autoranging, Display update.
CAL Factor Range: 001 to 199
Timer: Can set 1-10 minute sampling periods in one minute

increments, 10-50 minute sampling periods in 10-

minute increments, and 1-24 hour sampling periods in

1-hour increments
Alert Range: mR/hr: 0 to 50

CPM: 0 to 160,000
Accuracy: ± 10%
Beeper: Operational in Audio mode only
Anti-Saturation: Readout holds at full scale in fields up to 100

times the maximum reading.
Temperature Range: -10° to +50° C , 14° to 122° F
Power: One 9-volt alkaline battery. Battery life is minimum

2160 hrs at normal background. Minimum battery life

is 625 hrs at 1 mR/hr.
Size: 150 x 80 x 30 mm (5.9” x 3.2” x 1.2”)
Weight: 323 grams (11.4 oz) including battery

Appendix B Sensitivity to Common Isotopes

Typical GM tube efficiency for 4 Pi geometry at contact

Isotope E max. MeV Efficiency
Beta

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C 49 keV Avg. 156 keV Max. 5.3%

210

Bi 390 keV Avg. 1.2 MeV Max. 32%

90

Sr(Y) 546 keV and 2.3 MeV 38%

32

P 693 keV Avg. 1.7 MeV max. 33%

Alpha

241

Am 5.5 MeV 18%

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Appendix C - Inspector++ EXP Carrying Case

The unique design of
attaching the probe to the
carrying case allows one
handed operation.

The carrying case has a clear window panel
providing full view of the readout, count light
and access to the switches. Convenient
hand straps and a belt loop are provided for
carrying the instrument.

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The reinforced protective probe

cover prevents damage to the
fragile window of the detector.

The front flap lifts out of the way to gain
access to switches and a small pocket is
provided to hold a check source. For the
protection of the user, we recommend that
you use a .1 microcurie Cesium 137 check
source shielded on both sides. Gamma
shields for this source are available through
your distributor.