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Published by capintec, 2015-10-09 11:55:51

CAPRAC ® -R Wipe Test / Well Counter Manual- Revision J

CAPINTEC, INC. CAPRAC®-R

The CAPRAC-R adds the standard deviation to the total to determine if the result is above
established trigger levels. For example, if the trigger level for background is 1000 cpm, and
the CAPRAC-R measures 900 ± 140 cpm, the CAPRAC-R will indicate that this reading
exceeds the trigger level as 900 + 140 is greater than the trigger level of 1000 cpm.

NET VERSUS TOTAL COUNTS

The CAPRAC-R calculates net counts by subtracting the background counts in each
channel. With the exception of background activity, the CAPRAC-R always reads net counts.
The number displayed while counting in number display is total counts.

MAXIMUM COUNT RATE

The maximum count rate for the CAPRAC-R is 60,000 counts per second (cps). If a sample
or source placed in the detector exceeds this count rate, the message “COUNTING RATE
TOO HIGH – REMOVE SOURCE” will appear.

Standard sources for testing and calibrating the CAPRAC-R should be in the range of 0.1 to
1.0 µCi (3.7-37 kBq).

March 10 GENERAL OPERATING INSTRUCTIONS 3-7



CAPINTEC, INC. CAPRAC®-R

CHAPTER 4

WIPE TEST MEASUREMENTS

GENERAL

The CAPRAC®-R has the ability to distinguish between four wipe categories:

• Wipe (work areas)

• Unrestricted

• Sealed Source

• General

“Wipe” is used to assess possible contamination in work areas. “Unrestricted” is most often
used for public areas (e.g. waiting and patient rooms). “Sealed Source” is self explanatory
and include flood phantoms, calibration sources, spot markers, etc. “General” is the final
category and is used for measuring liquid samples (e.g. blood or urine) for laboratory
procedures or other general source measurements where a trigger level is not required.

WIPE (WORK AREAS)

Press the WIPE key. Figure 4-1 Wipe Counting Period Screen will appear.

W-01 6s

µ ¶ ´ to change
COUNT to start

Figure 4-1 Wipe Counting Period Screen

The CAPRAC-R system can store up to 99 user-defined wipe locations. W-01 indicates a
wipe count from the user-defined location called ‘01’. At the conclusion of the counting
period, wipe test results associated with this location will be printed on the paper strip (if a
printer is included with the system) and should be recorded, as necessary with this wipe
location (see the suggested sample worksheets in the back of this manual).

Shading indicates the active portion of the display. To change the first digit of the wipe
location, use the © or ª arrow keys. When the correct digit is displayed, use the ¨ arrow

September 07 WIPE TEST MEASUREMENTS 4-1

CAPINTEC, INC. CAPRAC®-R

key to highlight the second digit. Repeat the process using the © or ª arrow keys to change
the second digit. When the correct wipe location is displayed, press the ¨ arrow key to move

to the counting period (Fig. 2).

W-01 6s

µ ¶ ´ to change
COUNT to start

Figure 4-2 Wipe Counting Period Screen

Use the © or ª arrow keys to set the number of seconds for the counting period. The six
choices for counting are 6, 20, 60, 180, 600 and 1800 seconds.

When the correct time is displayed, place the wipe sample in the detector and press the
COUNT key. Figure 4-3 Wipe Count Screen (Graph Display) will appear showing the
number of counts in each of the CAPRAC-R’s six channels.

k 660 kcpm,n
e 400
V 200 0.44
40.92
100 47.34
60.15
39.08
80.64

Figure 4-3 Wipe Count Screen (Graph Display)

The time counts down from the initial setting (e.g. 60s) to zero. The CAPRAC-R updates the
bar graph and cpm each second; therefore, the net counts in cpm will change throughout the
counting period.

To change the display format from Figure 4-3 Wipe Count Screen (Graph Display) to Figure
4-4 Wipe Count Screen (Number Display), press the DISPLAY key. The display format can
be changed from graph to number format as often as desired without disrupting the counting
period during background or wipe test counting.

4-2 WIPE TEST MEASUREMEMTS September 07

CAPINTEC, INC. CAPRAC®-R

W-01 13s

36.60kc
66.37kcpm

Figure 4-4 Wipe Count Screen (Number Display)

At the end of the counting period, Figure 4-5 Wipe Count Screen (End of Counting Period)
will appear showing the net total counts (C) and the net counts per minute (cpm) for all
channels added together.

W-01

net

264.2kcpm

± .5kcpm

Figure 4-5 Wipe Count Screen (End of Counting Period)

By pressing the DISPLAY key, Figure 4-6 Wipe Count Exceeds Screen (Nuclide List) will
appear showing the estimated counts for any nuclides selected for this wipe category that
exceed trigger limits.

W-01 EXCEEDS

dpm,n
I 131 81.7 ± 0.4k

Figure 4-6 Wipe Count Exceeds Screen (Nuclide List)

The data in shown do not conclusively indicate that this wipe sample contains excessive
counts of I-131. Remember, the CAPRAC-R discriminates between pulses of various
amplitudes, or energy levels, dividing the whole spectrum of pulse amplitudes into six
channels:

September 07 WIPE TEST MEASUREMENTS 4-3

CAPINTEC, INC. CAPRAC®-R

Channel Energy Range in keV

1 15 to 100
2 100 to 200
3 200 to 400
4 400 to 660
5 660 to 800
6 > 800

Therefore, the correct interpretation of the results demonstrated in Figure 4-6 Wipe Count
Exceeds Screen (Nuclide List) is that if all the counts detected in CAPRAC-R channels 3 and
4 were from I-131, then the sample is hot. It is up to the user to correctly interpret the results.

Pressing the DISPLAY key again will display any nuclides that fall below the trigger levels
that have been established in the CAPRAC-R (Fig. 7). In this example, 2000 dpm has been
established for wipe levels in work areas.

W-01 OK dpm,n
± 47.6
CF 393.8 ± 45.8
Tc99m 81.7

Figure 4-7 Wipe Count OK Screen (Nuclide List)

The ‘generic’ nuclide, noted as ‘CF’ in Figure 4-7 Wipe Count OK Screen (Nuclide List), is
used to classify counts from all six channels. The generic nuclide is a general measurement
of the wipe sample that does not attempt to narrow down the possible nuclides contained in
the sample. Departments may choose to limit the report to the generic classification under
the assumption that if the generic count exceeds the trigger level, contamination is present, if
the generic count is below the trigger level, no contamination is present. For information
regarding identification of specific nuclides in a wipe test, refer to CHAPTER 7: NUCLIDES
TO LOOK FOR IN WIPES.

Reminder; the correct interpretation of the results demonstrated in Figure 4-7 Wipe Count
OK Screen (Nuclide List) is that if all the counts detected in CAPRAC-R channel 2 were from
Tc99m, then the activity in dpm noted in channel 2 would be attributed to Tc99m. However,
the energy range for channel 2 is 100-200 keV; therefore, detected energy in that channel
could be Tc99m (140 keV), Tl201 (167 keV) or any other nuclide with that energy range. It is
up to the user to correctly interpret the results.

If all selected nuclides fall below the trigger level, only Figure 4-7 Wipe Count OK Screen
(Nuclide List) will appear. If all selected nuclides exceed the trigger level, only Figure 4-6
Wipe Count Exceeds Screen (Nuclide List) will appear.

4-4 WIPE TEST MEASUREMEMTS September 07

CAPINTEC, INC. CAPRAC®-R

Press the ENTER key to print the final report. (if a printer is included with the system)

Note: If the nuclide list is too long to fit on one screen, an asterisk ‘*’ will appear at the
bottom of the screen. Press the DISPLAY key to view the second screen. When data
extends to a second screen, the ENTER and CF keys will not work on the first screen.
To print out the full report (if a printer is included with the system), press the ENTER
key from the final screen.

Press the DISPLAY key to return to the graph display (Fig. 9).

k 660 cpm,n
e 400
V 200 16.
452.
100 1313.
1390.
1303.
1207.

Figure 4-8 Wipe Count Results Screen (Graph Display)

Press the DISPLAY key to keep changing between the Wipe Count Screens.

BAR GRAPH SHADING

The overall length of each bar in the bar graph always indicates total counts (wipe sample
plus background) for each channel.

The solid shaded length of each bar in the bar graph always indicates net counts (wipe
sample minus background) for each channel.

The numbers in the column at the right side of the screen always indicate net counts (wipe
sample minus background) for each channel. This number corresponds to the solid section
of each bar. Consequently, the overall length of a bar for a certain channel may appear
larger than the other bars when the corresponding number of net counts is smaller than the
others.

When net counts are a smaller percentage of total counts, the bars will be partially shaded as
shown in Figure 4-9 Wipe Measurement Bar Graph.

September 07 WIPE TEST MEASUREMENTS 4-5

CAPINTEC, INC. CAPRAC®-R

k 660 cpm,n
e 400
V 200 16.
452.
100 1313.
1390.
1303.
1207.

Figure 4-9 Wipe Measurement Bar Graph Results

Because the CAPRAC-R indicates net counts on the bar graph by shading portions of the
bars that represent net counts, bar graphs of background measurements are always un-
shaded.

In the example shown in Figure 4-10 Wipe Measurement Bar Graph Results – All Shaded,
the net counts are high compared to the background levels; therefore, the background
activity is too small to see with the resolution of the display. As a result, the entire bar for
each channel is shaded.

k 660 cpm,n
e 400
V 200 16.
452.
100 1313.
1390.
1303.
1207.

Figure 4-10 Wipe Measurement Bar Graph Results – All Shaded

NEGATIVE NUMBERS

For some wipe samples, you may find negative numbers listed in the net count column (at
the right side of Figure 4-9 Wipe Measurement Bar Graph). This does not indicate device
malfunction.

Negative numbers occur when total counts minus background counts for a particular channel
is less than zero. This can happen when the background activity has changed, when count
rates are very low, or when there is no activity on the wipe or when counting times are
particularly long and background activity is slightly variable.

Negative counts should be small numbers. Large negative numbers indicate a significant
change in background activity, and the background count should be repeated.

4-6 WIPE TEST MEASUREMEMTS September 07

CAPINTEC, INC. CAPRAC®-R

Pressing the ENTER key from the Wipe Count Screen will print the total counts and the
counts for each selected nuclide on the paper strip (if a printer is included with the system)
as shown in Figure 4-11 Wipe Count, All Nuclides Displayed (Paper Strip).

Dec 14,2006 10:13 60sec
2 kcpm,net
W-01 66.10 ± 47.6 dpm

CF: 1.75 393.8 ± .4 dpm
45.8 kdpm
I 131 81.70 ±

Tc99m 378.0 ±

Figure 4-11 Wipe Count, All Nuclides Displayed (Paper Strip)

WIPE PRINTOUT

If a printer is included with the system, the paper strip includes the date, time, counting
period (in seconds) and wipe location number.

The next line displays the total counts per minute (cpm) for all six CAPRAC-R channels. The
next line shows the calculated disintegrations per minute (dpm) for the ‘generic’ nuclide. The
first column of the generic line indicates the conversion factor (CF) designated in the
CAPRAC-R for the generic nuclide. If a CF value has not been stored for the generic nuclide,
the printout will display the CF value as 2.7. Remember; dpm values are calculated by
multiplying cpm values by the CF number.

This strip can be used as documentation of wipe test monitoring. To save time and eliminate
errors in recording wipe data, the sample worksheets in the back of this manual can be
modified to accommodate the paper strips.

Pressing the ENTER key from the horizontal bar graph display (Figure 4-9 Wipe
Measurement Bar Graph Results) will print the bar graph as well as the total counts and the
counts from each selected nuclide.

SPECIFIC NUCLIDES

To see the estimated counts for specific nuclides, press the CF (nuclide) key. For the
current example, pressing the CF (nuclide) key will display between the following four
screens. Regardless of whether the user has selected specific nuclides to be displayed, the
generic count (Figure 4-13 Wipe Count Screen (Nuclide Key)) will always be calculated and
displayed. Remember; if a new conversion factor (CF) has not been stored in the CAPRAC-
R, to calculate cpm from dpm, divide the dpm by 2.7 (manufacturer installed CF).

September 07 WIPE TEST MEASUREMENTS 4-7

CAPINTEC, INC. CAPRAC®-R

W-01
net

264.2kcpm
± .5kcpm

Figure 4-12 Wipe Count Screen (Nuclide Key)

W-01
CF

net

115.67kdpm

± .35kdpm

Figure 4-13 Wipe Count Screen (Nuclide Key)

W-01

I 131 HIGH

net

81.7kdpm

± .4kdpm

Figure 4-14 Wipe Count Screen (Nuclide Key)

W-01
Tc99m

net

12.19kdpm

± .97kdpm

Figure 4-15 Wipe Count Screen (Nuclide Key)

4-8 WIPE TEST MEASUREMEMTS September 07

CAPINTEC, INC. CAPRAC®-R

The displayed screens will indicate if a selected nuclide is high (as shown in Figure 4-14
Wipe Count Screen (Nuclide Key)).

Note: If the nuclide list is longer than one screen, pressing the CF (nuclide) key to view the
estimated counts for an individual nuclide will only work when making that selection
from the last screen (end of nuclide list). Pressing the CF (nuclide) key during the
counting period will display one of the examples noted in the previous figures. The
dpm values and the remaining time will be updated each second. To return to the
regular screen during the counting period, press the DISPLAY key.

The graph displays for the previous figures are dependent on the information provided.
Figure 4-12 Wipe Count Screen (Nuclide Key) displays total counts per minute (cpm). The
display does not indicate a dpm value or specific nuclide. The graph displayed by pressing
the DISPLAY key will have solid shading for all horizontal bars (Figure 4-10 Wipe
Measurement Bar Graph Results – All Shaded). When a graph is displayed for a specific
nuclide (Figure 4-15 Wipe Count Screen (Nuclide Key)), the graph will have solid shading in
the horizontal bar(s) representing the channel(s) assigned to the nuclide and no shading for
the net counts in the remaining channels. For Tc99m, the second bar, channel 2 (100-200
keV), has been assigned; therefore, net counts are displayed as solid shading in the second
channel (Fig. 16).

k 660 cpm,n
e 400
V 200 191.
272.
100 730.
976.
1225.
1031.

Figure 4-16 Wipe Bar Graph Results – Selected Nuclide

Pressing the ENTER key will produce a printout (if a printer is included with the system) with
the same solid shading displayed on the CAPRAC-R screen.

UNRESTRICTED AREAS

Wipes defined as Unrestricted Areas most often represent public areas and patient rooms.
To count a wipe sample from an unrestricted area, press the WIPE and UTIL key to return to
Figure 4-17 Main Utility Menu.

September 07 WIPE TEST MEASUREMENTS 4-9

CAPINTEC, INC. CAPRAC®-R

f COUNT
TESTS

SETUP

DIAGNOSTICS

µ or ¶ to change
ENTER to select

Figure 4-17 Main Utility Menu

Select COUNT, then press the ENTER key. Figure 4-18 Count Menu will appear.

f UNRESTRICTED
SEALED SOURCE
GENERAL

Figure 4-18 Count Menu

Select UNRESTRICTED, then press the ENTER key. Figure 4-19 Unrestricted Wipe
Counting Period Screen will appear.

U-01 60s

µ ¶ ´ to change
COUNT to start

Figure 4-19 Unrestricted Wipe Counting Period Screen

‘U-01’ indicates a wipe count from the user-defined location called ‘01’. At the conclusion of
the counting period, wipe test results associated with this location will be printed on the paper
strip (if a printer is included with the system) and should be recorded, as necessary with this
wipe location (see suggested sample worksheets in the back of this manual). Use the © or ª
arrow keys to set the correct wipe location. When the correct wipe location is displayed, use
the ¨ arrow key to move to the counting period, then use the © or ª arrow keys set the
desired counting period.

4 - 10 WIPE TEST MEASUREMEMTS September 07

CAPINTEC, INC. CAPRAC®-R

To count and record Unrestricted wipe samples, follow the instructions for counting and
recording Wipe samples from the work area.

SEALED SOURCE

Regulatory guidelines require assessment of sealed sources to detect leakage on a periodic
basis. To count a wipe from an sealed source, press the WIPE and UTIL keys to return
Figure 4-20 Main Utility Menu.

f COUNT
TESTS
SETUP
DIAGNOSTICS

µ or ¶ to change
ENTER to select

Figure 4-20 Main Utility Menu

Select COUNT, then press the ENTER key. Figure 4-21 Count Menu will appear.

UNRESTRICTED
f SEALED SOURCE

GENERAL

Figure 4-21 Count Menu

Use the ª arrow key to select SEALED SOURCE, then press the ENTER key, Figure 4-22
Sealed Source Counting Period Screen will appear.

September 07 WIPE TEST MEASUREMENTS 4 - 11

CAPINTEC, INC. CAPRAC®-R

S-01 6s

µ ¶ ´ to change
COUNT to start

Figure 4-22 Sealed Source Counting Period Screen

‘S-01’ indicates a wipe count from the user-defined sealed source called ‘01’. At the
conclusion of the counting period, wipe test results associated with this sealed source will be
printed on the paper strip (if a printer is included with the system) and should be recorded, as
necessary for this sealed source (see the suggested sample worksheets in the back of this
manual). Use the © or ª arrow keys to set the correct sealed source number. When the
correct wipe location is displayed, use the ¨ arrow key to move to the counting period, then
use the © or ª arrow keys set the desired counting period.

To count and record sealed source wipe samples, follow the instructions listed for counting
and recording wipe samples from the work area.

Note: The CF (nuclide) key does not work for Sealed Source wipes because the CAPRAC-
R will only assess the wipe sample for one isotope. If the printout (if a printer is
included with the system) does not specify a nuclide, no nuclide was selected for this
Sealed Source location (refer to CHAPTER 7: NUCLIDES TO LOOK FOR IN
WIPES).

GENERAL

The General Counting Function is used to measure samples (e.g. blood and urine) for
laboratory procedures. Additionally, thin-layer chromatography strips may be counted to
assess radiochemical purity in the General Counting Function providing that the activity on
the strips does not exceed 60,000 cps.

Press the WIPE and UTIL keys to return to Figure 4-23 Main Utility Menu.

f COUNT
TESTS
SETUP
DIAGNOSTICS

µ or ¶ to change
ENTER to select

Figure 4-23 Main Utility Menu

4 - 12 WIPE TEST MEASUREMEMTS September 07

CAPINTEC, INC. CAPRAC®-R

Select COUNT, then press the ENTER key. Figure 4-24 Count Menu will appear.

UNRESTRICTED
SEALED SOURCE
f GENERAL

Figure 4-24 Count Menu

Use theª arrow key to select GENERAL, then press the ENTER key. Figure 4-25 General
Counting Period Screen will appear.

G-01 20s

µ ¶ ´ to change
COUNT to start

Figure 4-25 General Counting Period Screen

It is not possible to store a location or nuclide information for General Wipes; therefore, it is
unnecessary to change the G-01 setting. Use ¨ arrow key to move to the counting period,
then use the © or ª arrow keys set the desired counting period.

Press the ENTER key. Figure 4-26 Channel Assignment Screen will appear showing the list
of the six CAPRAC-R spectroscopy channels.

G-01 20s
f CH 1 CH 4

CH 2 CH 5
CH 3 CH 6

µ ¶ ´ to change
COUNT to start

Figure 4-26 Channel Assignment Screen

September 07 WIPE TEST MEASUREMENTS 4 - 13

CAPINTEC, INC. CAPRAC®-R

Use the © or ª arrow keys move the cursor to the channel that includes the energy peaks
for the nuclides being counted. Use the ¨ arrow key to select the channel, as noted by

shading. When all channels have been selected for the energy peaks included in the
nuclide1, press the COUNT key to count the sample.

Note: At least one channel must be selected prior to counting. To measure a ‘generic’
nuclide sample, select all six channels.

Figure 4-27 General Wipe Count Screen will appear.

G-01 13s

38. C
293.9 cpm

Figure 4-27 General Wipe Count Screen

To count and record General wipe samples, follow the instructions listed for counting and
recording Wipe samples from the work area.

1 Gamma energy peaks for nuclides can be found in: A Handbook of Radioactivity Measurements Procedures (NCRP Report
No. 58, Appendix A.3, National Council on Radiation Protection and Measurements, Bethesda, Maryland.

4 - 14 WIPE TEST MEASUREMEMTS September 07

CAPINTEC, INC. CAPRAC®-R

CHAPTER 5

TRIGGER LEVELS: SETTING COUNT
LIMITS

GENERAL

The CAPRAC®-R stores trigger levels for measurements from:
• Wipe tests:
o Work areas
o Unrestricted areas
o Sealed Sources
• Background activity

Trigger levels are count limits that determine when a user-defined measurement is too high.
To set trigger levels, press the WIPE and UTIL keys to display Figure 5-1 Main Utility Menu.

f COUNT
TESTS
SETUP
DIAGNOSTICS

µ or ¶ to change
ENTER to select

Figure 5-1 Main Utility Menu

Use the ª arrow key to select SETUP. Press the ENTER key. Figure 5-2 Setup Menu will
appear.

TIME
AUTO CAL
f OTHER

January 08 Figure 5-2 Setup Menu 5-1

TRIGGER LEVELS: SETTING COUNT LIMITS

CAPINTEC, INC. CAPRAC®-R

Use the ª arrow key to move the cursor to select OTHER. Press the ENTER key. Figure 5-3
Password Screen will appear.

PASSWORD

000

µ ¶ ´ to change
ENTER to accept

Figure 5-3 Password Screen

Use the © or ª and ¨ arrow keys to enter the password. When the correct password is
displayed, press the ENTER key. Figure 5-4 Other Setup Menu will appear.

f NUCLIDES
Ci/Bq
TRIGGER LEVEL
ACTIVITY CF
STD. SOURCE
RESET HV

Figure 5-4 Other Setup Menu

Use the ª arrow key to move the cursor to select TRIGGER LEVEL. Press the ENTER key.
Figure 5-5 Trigger Level Menu will appear.

f WIPE
UNRESTRICTED
SEALED SOURCE
BACKGROUND

Figure 5-5 Trigger Level Menu
Use the ª arrow key to move the cursor to select WIPE. Press the ENTER key.

5-2 TRIGGER LEVELS: SETTING COUNT LIMITS January 08

CAPINTEC, INC. CAPRAC®-R

WIPE
TRIGGER LEVEL

02000. dpm

µ ¶ ´ to change
ENTER to accept

Figure 5-6 Wipe Level Screen

Use the © or ª and ¨ arrow keys to enter the trigger level. When the correct trigger level is
displayed, press the ENTER key to return to Figure 5-5 Trigger Level Menu.

Repeat this process to set trigger levels for the remaining wipe categories. Refer to

Table 5-1 Commonly Used Trigger Levels and Table 5-2 Minimum and Maximum Accepted
Values for CAPRAC-R Trigger Levels for commonly used trigger levels and acceptable
ranges.

Note: If the desired trigger is in the hundreds (3 digits), rather than thousands (4 digits), use
the ª arrow key on the first digit until the ‘0’ disappears, leaving a blank space. That
same process would be used if the trigger level was 1 or 2 digits.

Reminder: The CAPRAC-R will not accept a blank space for certain digits when it would be
inappropriate.

If the trigger levels do not fall within CAPRAC-R’s minimum and maximum accepted values,
the message “INPUT ERROR – SEE MANUAL” will appear:

When the ENTER key is pressed, the screen returns to Figure 5-6 Wipe Level Screen,
allowing for re-entry of the trigger level.

COMMONLY USED TRIGGER LEVELS AND ACCEPTABLE RANGES

Table 5-1 Commonly Used Trigger Levels

Category Curies Becquerels

WIPE 2000 dpm 33.3 Bq
UNRESTRICTED 200 dpm 3.3 Bq
SEALED SOURCE 5 nCi
BACKGROUND 185.0 Bq
1000 cpm 17.0 cps

January 08 TRIGGER LEVELS: SETTING COUNT LIMITS 5-3

CAPINTEC, INC. CAPRAC®-R

Table 5-2 Minimum and Maximum Accepted Values for CAPRAC-R Trigger Levels

Category Curies Becquerels

WIPE MINIMUM MAXIMUM MINIMUM MAXIMUM
UNRESTRICTED
SEALED SOURCE 60 dpm 25000. dpm 0.1 Bq 417.0 Bq
BACKGROUND
60 dpm 2500.0 dpm 0.1 Bq 41.7 Bq

0.1 nCi 270.0 nCi 3.7 Bq 9999. Bq

60 cpm 9999.9 cpm 1. cps 166.0 cps

MINIMUM DETECTABLE ACTIVITY (MDA)

Regulatory guidelines may require instruments that are used to measure wipe samples for
radioactive contamination be evaluated to determine the minimum level of activity that can be
detected by that instrument.

The minimum detectable activity (MDA) is dependent on the background levels where the
instrument is located and the counting time used to assess the background rate.

Because these variables are user-dependent, it is not possible for Capintec to publish an
MDA for the CAPRAC-R. Capintec recommends that users determine the appropriate
counting time based on the required MDA limit for their application as well as the ambient
background rates where the instrument is located.

The CAPRAC-R includes a test that will provide MDA values for a specific nuclide selected
by the user. The test measures the background in the channels (ROI) that would be used to
measure the activity of the selected nuclide and calculates the MDA for that nuclide. Refer to
CHAPTER 16: MDA TEST for instructions on performing an MDA Test.

5-4 TRIGGER LEVELS: SETTING COUNT LIMITS January 08

CAPINTEC, INC. CAPRAC®-R

CHAPTER 6

CONVERSION FACTORS FOR
NUCLIDES

GENERAL

Conversion Factors are constants used to convert measurements in counts per minute (cpm)
to disintegrations per minute (dpm). The CAPRAC®-R calculates conversion factors by
measuring counts (in cpm) from a calibrated sample of a specific radionuclide. Because the
sample has been calibrated, the CAPRAC-R can calculate the dpm value for that sample.
Finally, the CAPRAC-R divides the dpm value by the cpm value to determine the conversion
factor (CF) for that radionuclide.

CF for radionuclide = disintegrations per minute
counts per minute

Conversion factor values are affected by:
• Geometry
• Detector efficiency
• Abundance of gamma energy peak(s)
• CAPRAC-R channels selected for the nuclide

For this reason, it is recommended that conversion factors be measured, rather than input
into the CAPRAC-R. Additionally, it is not recommended to input conversion factors
calculated from other radiation measurement devices into the CAPRAC-R; however, the user
may decide to input conversion factors for radionuclides calculated by others for the
CAPRAC-R.

To calculate the activity for a specific radionuclide, the conversion factor for that nuclide must
be stored in the CAPRAC-R system. Additionally, the conversion factor for the standard
reference source (Cs137 or Ba133) must be measured and stored in the system at the time
of initial set-up or when a new reference standard is obtained.

The CAPRAC-R allows the user to input or measure conversion factors for the 68
radionuclides stored in the unit by the manufacturer. Additionally, conversion factors for 10
user-defined radionuclides as well as a ‘generic’ nuclide can be added to the unit.

Reminder: To report wipe test monitoring results in dpm, the user must store a conversion
factor for each radionuclide that may be present in the wipe sample. For the generic nuclide,
it is important to remember that the conversion factor is not the measurement of a specific
nuclide; rather, it is the combined count rate from all six CAPRAC-R channels. Therefore, the
findings from a generic reading should only be used to initiate further investigation should the
reading exceed the allowable limits for that wipe sample.

September 07 CONVERSION FACTORS FOR NUCLIDES 6-1

CAPINTEC, INC. CAPRAC®-R

ADDING CF VALUES

There are two methods to store a CF value in the CAPRAC-R: MEASURE and INPUT.

Note: The CF value for the generic nuclide cannot be measured – it must be entered, or
input into the system.

Measure CF Value
To measure a conversion factor for a specific nuclide, press the WIPE and UTIL keys to
display Figure 6-1 Main Utility Menu.

f COUNT
TESTS
SETUP
DIAGNOSTICS

µ or ¶ to change
ENTER to select

Figure 6-1 Main Utility Menu

Use the ª arrow key to select SETUP. Press the ENTER key. Figure 6-2 Setup Menu will
appear.

TIME
AUTO CAL
f OTHER

Figure 6-2 Setup Menu

Use the ª arrow key to move the cursor to select OTHER. Press the ENTER key. Figure 6-3
Password Screen will appear.

6-2 CONVERSION FACTORS FOR NUCLIDES September 07

CAPINTEC, INC. CAPRAC®-R

PASSWORD

000

µ ¶ ´ to change
ENTER to accept

Figure 6-3 Password Screen

Use the © or ª and ¨ arrow keys to enter the password. When the correct password is
displayed, press the ENTER key. Figure 6-4 Other Setup Menu will appear.

f NUCLIDES
Ci/Bq
TRIGGER LEVEL
ACTIVITY CF
STD. SOURCE
RESET HV

Figure 6-4 Other Setup Menu

Use the ª arrow key to move the cursor to select ACTIVITY CF. Press the ENTER key.
Figure 6-5 Select Nuclide Screen will appear.

Nuclide:

I 131

CF key for generic
µ ¶ ´ to change
ENTER to accept

Figure 6-5 Select Nuclide Screen

Figure 6-5 Select Nuclide Screen allows the user to enter the appropriate radionuclide prior
to measuring the conversion factor.
Use the © or ª arrow keys to select the first letter of the radionuclide. Use the ¨ arrow key
to highlight the next letter. Repeat the process using the © or ª arrow keys to select the

September 07 CONVERSION FACTORS FOR NUCLIDES 6-3

CAPINTEC, INC. CAPRAC®-R

appropriate letter or number and the ¨ arrow key to move to the next space. When the
correct radionuclide is displayed, press the ENTER key.

If a conversion factor for the selected nuclide has already been stored in the unit, Figure 6-6
Nuclide CF Data Screen will appear.

Note: If a CF value has not been stored in the CAPRAC-R for the selected nuclide, the
system will move directly to Figure 6-7 CF Menu.

Nuclide:

I 131
CF: 5.30
CH: 3

OK?
Yes(µ) or No(¶):

Figure 6-6 Nuclide CF Data Screen

Press the ª arrow and the ENTER keys. Figure 6-7 CF Menu will appear.

f INPUT CF
MEASURE CF

Figure 6-7 CF Menu

Press the ª arrow key to move the cursor to MEASURE CF. Press the ENTER key. Figure
6-8 Activity Unit Screen will appear.

CALIB ACTIVITY:
ACTIVITY IN

Ci
Bq

Figure 6-8 Activity Unit Screen

6-4 CONVERSION FACTORS FOR NUCLIDES September 07

CAPINTEC, INC. CAPRAC®-R

Calibration data can be entered in Curies or Becquerels:
Use the © or ª arrow keys to highlight the appropriate activity unit. Press the ENTER key.
Figure 6-9 Nuclide Calibrated Activity Screen will appear.

CALIB ACTIVITY:

0.0000 µCi

µ ¶ ´ to change
ENTER to accept

Figure 6-9 Nuclide Calibrated Activity Screen

Calibrate the source, then using the © or ª arrow keys and the ¨ arrow key, input the
measured activity.
Note: The calibrated activity should be in the range of 0.1 to 1.0 µCi (3.7-37 kBq).
When the correct activity has been input, press the ENTER key. Figure 6-10 Nuclide
Calibration Date Screen will appear.

CALIB DATE:

JUL 09 06

µ ¶ ´ to change
ENTER to accept

Figure 6-10 Nuclide Calibration Date Screen

Use the © or ª arrow keys and the ¨ arrow key to input the correct date. When the correct
month, day and year is displayed, press the ENTER key. Figure 6-11 Nuclide Calibration
Time Screen will appear.

September 07 CONVERSION FACTORS FOR NUCLIDES 6-5

CAPINTEC, INC. CAPRAC®-R

CALIB TIME:

12:00

µ ¶ ´ to change
ENTER to accept

Figure 6-11 Nuclide Calibration Time Screen

Using the © or ª arrow keys and the ¨ arrow key, input the correct time of calibration.

Note: The CAPRAC-R runs on a 24 hour clock. 9:30 a.m. is set as 09:30. 1:30 p.m. is set
as 13:30.

When the correct time is displayed, press the ENTER key.

I 131
.1080µCi

DEC 20 2006
08:45

OK?
Yes(µ) or No(¶):

Figure 6-12 Calibration Data Screen

Figure 6-12 Calibration Data Screen will appear showing the nuclide data entered. If the
information is not correct, press the ª arrow key and the system will return Figure 6-8
Activity Unit Screen.

If the displayed information is correct, press the © arrow key. Figure 6-13 Measure Nuclide
Source Screen.

MEASURE SOURCE

ENTER to Continue

Figure 6-13 Measure Nuclide Source Screen

6-6 CONVERSION FACTORS FOR NUCLIDES September 07

CAPINTEC, INC. CAPRAC®-R

Place the calibrated source in the detector and press the ENTER key. Figure 6-14 Nuclide
Counting Period Screen will appear.

20s

µ or ¶ to change
COUNT to Start

Figure 6-14 Nuclide Counting Period Screen

Use the © or ª arrow keys to set the number of seconds for the counting period. The six
choices for counting are 6, 20, 60, 180, 600 and 1800 seconds.

When the correct time is displayed, press the COUNT key. Figure 6-15 Nuclide Count
Screen (Graph Display) will appear showing the number of counts in each of the CAPRAC-
R’s six channels. The remaining time and net number of counts (in cpm) will be updated
each second.

k 660 kcpm,n
e 400
V 200 0.39
40.70
100 49.20
61.40
39.36
80.43

Figure 6-15 Nuclide Count Screen (Graph Display)

To change the screen format from Figure 6-15 Nuclide Count Screen (Graph Display) to
Figure 6-16 Nuclide Count Screen (Number Display), press the DISPLAY key.

September 07 CONVERSION FACTORS FOR NUCLIDES 6-7

CAPINTEC, INC. CAPRAC®-R

29s

36.60kc
66.37kcpm

Figure 6-16 Nuclide Count Screen (Number Display)

Figure 6-16 Nuclide Count Screen (Number Display) shows net total counts (C) and the
combined net counts per minute (cpm) for the six CAPRAC-R channels.

If the count rate is too low (<5000 cpm), the message “SOURCE TOO WEAK – SEE
MANUAL – ENTER TO CONTINUE” will appear.

At the end of the counting period, Figure 6-17 Channel Assignment Screen will appear.

´ to select channels

CH 1 f CH 4
CH 2 CH 5
CH 3 CH 6

ENTER when finished

Figure 6-17 Channel Assignment Screen

The Channel Assignment Screen allows the user to select the channel(s) to be used to
determine the conversion factor. Press the ª arrow key to move the cursor. Press the ¨

arrow key to select a channel. Shading indicates that the channel has been selected. The

cursor will automatically move to the next channel. Repeat the process to select the

appropriate channel(s).

For I-131, channel 3 with a keV range of 200-400 would be selected.

Channel Energy Range in keV

1 15 to 100
2 100 to 200
3 200 to 400
4 400 to 660
5 660 to 800
6 > 800

6-8 CONVERSION FACTORS FOR NUCLIDES September 07

CAPINTEC, INC. CAPRAC®-R

Note: If a channel is selected in error, place the cursor next to the highlighted (incorrect)
channel and press the ¨ arrow key to deselect the incorrect channel.

When the correct channels have been selected (highlighted), press the ENTER key. Figure
6-18 Nuclide CF Data Screen will appear.

I 131

CF: 5.30
CH: 3

OK?
Yes(µ) or No(¶):

Figure 6-18 Nuclide CF Data Screen

Press the © arrow key to accept the data, press the ª arrow key if the data is incorrect and
revisions are required.

Table 6-1 Gamma Energy Peaks and Recommended Channels lists gamma energy peaks
and CAPRAC-R channels recommended for measurement of some commonly used
radionuclides. A recommended reference source for gamma energy peaks for radionuclides
is: “Table of Nuclear-Decay Data,” Appendix A.3 in A Handbook of Radioactivity
Measurements Procedures ((NCRP Report No. 58), National Council on Radiation Protection
and Measurements, Bethesda, Maryland.

Table 6-1 Gamma Energy Peaks and Recommended Channels

Nuclide Energy Peak CAPRAC-R
(in keV) Channel(s)
Tc99m 140
Tl201 167 1, 2
I123 159 1, 2
I125 35
I131 364 2
In111 171, 245 1
Ga67 3
F18 93, 184, 300 2, 3, 4
Cr51 511 1, 2, 3
Co57 320 4
Co60 122 3
Cs137 2
Ba133 1173, 1132 3, 4, 5, 6
662 4, 5
1, 2, 3, 4
80, 302, 356

September 07 CONVERSION FACTORS FOR NUCLIDES 6-9

CAPINTEC, INC. CAPRAC®-R

Input CF Value
Capintec recommends that CF values be measured rather than input into the system;
however the CAPRAC-R program allows the user to input CF numbers.

Note: The CF value for the ‘generic’ nuclide cannot be measured, it must be input. Refer to
‘Generic CF’ in the next section of this chapter.

To input a conversion factor for a specific nuclide:
• Press the WIPE and UTIL keys to return to the Main Utility Menu.
• Select SETUP, then press the ENTER key.
• Select OTHER, then press the ENTER key.
• Input the password, then press the ENTER key.
• Select ACTIVITY CF, then press the ENTER key.
• Enter the nuclide, then press the ENTER key.
• If the selected nuclide already has a CF, then press the ª arrow key. Select INPUT
CF, then press the ENTER key. Figure 6-19 Input CF Screen will appear.

CONV. FACTOR

00.00

µ ¶ ´ to change
ENTER to accept

Figure 6-19 Input CF Screen

Use the © or ª arrow keys and the ¨ arrow key to input the correct conversion factor. Press
the ENTER key. Figure 6-17 Channel Assignment Screen will appear.

Note: The minimum accepted value is .001; the maximum accepted value is 9999.

Using the ª and ¨ arrow keys, select the appropriate channels for the radionuclide. Press
the ENTER key. Figure 6-18 Nuclide CF Data Screen will appear.

Input CF of Generic Nuclide
The ‘Generic” Nuclide is a term used to classify counts from all six channels. The CAPRAC-
R is programmed with a default generic CF value of 2.7 which is equivalent to I-131 using
channels 1, 2, 3, and 4 as shown in Figure 6-20 Generic CF Screen.

6 - 10 CONVERSION FACTORS FOR NUCLIDES September 07

CAPINTEC, INC. CAPRAC®-R

GENERIC

CF: 2.70

OK?
Yes(µ) or No(¶):

Figure 6-20 Generic CF Screen

To accept the displayed CF, press the © arrow key.
To reset the CF, press the ª arrow key. Figure 6-21 Generic CF Input Screen will appear.

CONV. FACTOR
00.00

µ ¶ ´ to change
ENTER to accept

Figure 6-21 Generic CF Input Screen

Use the © or ª arrow keys and the ¨ arrow key to input the correct conversion factor. Press
the ENTER key. Figure 6-17 Channel Assignment Screen will appear.
Note: The minimum accepted value is .001; the maximum accepted value is 9999.
Note: To establish a generic CF value, each institution should consult with a health

physicist or radiation safety officer.

September 07 CONVERSION FACTORS FOR NUCLIDES 6 - 11



CAPINTEC, INC. CAPRAC®-R

CHAPTER 7

NUCLIDES TO LOOK FOR IN WIPES

GENERAL

The CAPRAC®-R is not designed to identify specific radionuclides in a wipe sample;
however, the possibilities can be narrowed by determining which of the six CAPRAC-R
channels detect the pulse amplitude or energy level emitted from a wipe sample.

To determine when a wipe test exceeds the limit for a specific radionuclide, the conversion
factor for that radionuclide must be stored in the CAPRAC-R. Refer to CHAPTER 6:
CONVERSION FACTORS FOR NUCLIDES for information regarding measuring
(recommended) or inputting conversion factors.

NUCLIDE SELECTION

The CAPRAC-R can assess up to ten (10) separate radionuclides in the WIPE and
UNRESTRICTED categories and one (1) radionuclide for the SEALED SOURCE category.

Wipe and Unrestricted
To select the required radionuclide(s) for a Wipe or Unrestricted sample, press the WIPE and
UTIL keys to display Figure 7-1 Main Utility Menu.

f COUNT
TESTS
SETUP
DIAGNOSTICS

µ or ¶ to change
ENTER to select

Figure 7-1 Main Utility Menu

Use the ª arrow key to select SETUP. Press the ENTER key. Figure 7-2 Setup Menu will
appear.

September 07 NUCLIDES TO LOOK FOR IN WIPES 7-1

CAPINTEC, INC. CAPRAC®-R

TIME

AUTO CAL
f OTHER

Figure 7-2 Setup Menu

Use the ª arrow key to move the cursor to select OTHER. Press the ENTER key. Figure 7-3
Password Screen will appear.

PASSWORD

000

µ ¶ ´ to change
ENTER to accept

Figure 7-3 Password Screen

Use the © or ª and ¨ arrow keys to enter the password. When the correct password is
displayed, press the ENTER key. Figure 7-4 Other Setup Menu will appear.

f NUCLIDES
Ci/Bq
TRIGGER LEVEL
ACTIVITY CF
STD. SOURCE
RESET HV

Figure 7-4 Other Setup Menu

Select NUCLIDES by pressing the ENTER key. Figure 7-5 Wipe Category Menu will appear.

7-2 NUCLIDES TO LOOK FOR IN WIPES September 07

CAPINTEC, INC. CAPRAC®-R

f WIPE
UNRESTRICTED
SEALED SOURCE

Figure 7-5 Wipe Category Menu

To select up to 10 radionuclides for a WIPE or UNRESTRICTED wipe sample, select WIPE
or UNRESTRICTED, then press the ENTER key. Figure 7-6 Nuclide List Screen will appear.

f TC99m IN111
I 131 CO57
I 123 CR51
GA67 NA22
TL201 MN54

Figure 7-6 Nuclide List Screen

Figure 7-6 Nuclide List Screen contains a list of up to 68 stored nuclides for the Wipe and
Unrestricted categories. The first screen will display up to 10 radionuclides. To view
additional radionuclides, press the ª arrow key until the next screen appears (Figure 7-7
Nuclide List Screen (con’t)).

Note: Only those radionuclides that have stored conversion factors will be displayed on the
Nuclide List Screen. If a radionuclide is not displayed on the screen, a conversion
factor for that radionuclide has not been stored in the CAPRAC-R.

f CO60
I 125
BA133
CS137

September 07 Figure 7-7 Nuclide List Screen (con’t) 7-3

NUCLIDES TO LOOK FOR IN WIPES

CAPINTEC, INC. CAPRAC®-R

Shading indicates those radionuclides that were previously selected for this wipe category.
Use the © or ª arrow keys to move the cursor to the appropriate radionuclide. Use the ¨

arrow key to select (highlight) the radionuclide. The cursor will automatically move to the next

nuclide. If a radionuclide has been selected by mistake, move the cursor to the radionuclide
and use the ¨ arrow key to erase the shading. When all nuclides have been selected, press

the ENTER key. Figure 7-5 Wipe Category Menu will re-appear.

Sealed Source

The CAPRAC-R is designed to look for just one nuclide in wipes from sealed sources;
therefore, each sealed source wipe location (e.g. S-01, S-02, S-03) must always come from
the same location as it will have only nuclide assigned to it.

To assign a Sealed Source nuclide:
• Press the WIPE and UTIL keys to return to the Main Utility Menu.
• Select SETUP, then press the ENTER key.
• Select OTHER, then press the ENTER key.
• Input the password, then press the ENTER key.
• Select NUCLIDES, then press the ENTER key.
• Enter the nuclide, then press the ENTER key. Figure 7-8 Wipe Category Menu will
appear.

f WIPE
UNRESTRICTED
SEALED SOURCE

Figure 7-8 Wipe Category Menu

Select SEALED SOURCE and then press the ENTER key. Figure 7-9 Sealed Source
Location Number Screen will appear.

7-4 NUCLIDES TO LOOK FOR IN WIPES September 07

CAPINTEC, INC. CAPRAC®-R

S-01

Figure 7-9 Sealed Source Location Number Screen

Shading indicates the active portion of the display. To change the first digit of the location,
use the © or ª arrow keys. When the correct digit is displayed, use the ¨ arrow key to
highlight the second digit. Repeat the process using the © or ª arrow keys to change the

second digit. When the correct location is displayed, press the ENTER key. Figure 7-10

Nuclide List Screen will appear.

S-01 IN111
CO57
f TC99m CR51
I 131 NA22
MN54
I 123

GA67

TL201

Figure 7-10 Nuclide List Screen

To select a nuclide for this sealed source location (e.g. S-01), use the © or ª arrow keys to
move the cursor and the ¨ arrow key to select the nuclide.

Note: To view additional radionuclides, use the ª arrow key to display the next page. When
the correct nuclide is shaded, press the ENTER key. Figure 7-11 Sealed Source
Location Number Screen will appear showing the next location number.

S-02

Figure 7-11 Sealed Source Location Number Screen

September 07 NUCLIDES TO LOOK FOR IN WIPES 7-5

CAPINTEC, INC. CAPRAC®-R

Press the ENTER key to accept the next location number or use the © or ª and ¨ arrow
keys to input the desired location and press the ENTER key. Figure 7-12 Nuclide List
Screen will appear showing the desired location number.

S-02 IN111
CO57
f TC99m CR51
I 131 NA22
MN54
I 123

GA67

TL201

Figure 7-12 Nuclide List Screen

When all Sealed Source locations have been assigned a nuclide, press the UTIL key to
return to Figure 7-8 Wipe Category Menu.

7-6 NUCLIDES TO LOOK FOR IN WIPES September 07

CAPINTEC, INC. CAPRAC®-R

CHAPTER 8

USER-DEFINED NUCLIDES

GENERAL

The CAPRAC®-R comes with 68 nuclide names stored in the memory (refer to CHAPTER
10: DIAGNOSTICS, for information regarding obtaining a printout of stored nuclides (if a
printer is attached to the system)). The CAPRAC-R allows the user to add 10 additional
nuclide names to the memory. User-defined nuclides cannot be erased from the CAPRAC-
R’s memory; however, it is possible to write over existing user-defined nuclides should the
need arise.

ADDING A USER-DEFINED NUCLIDE

To add a user-defined nuclide, press the WIPE and UTIL keys to display Figure 8-1 Main
Utility Menu.

f COUNT
TESTS
SETUP
DIAGNOSTICS

µ or ¶ to change
ENTER to select

Figure 8-1 Main Utility Menu

Use the ª arrow key to select SETUP. Press the ENTER key. Figure 8-2 Setup Menu will
appear.

TIME
AUTO CAL
f OTHER

September 07 Figure 8-2 Setup Menu 8-1

USER-DEFINED NUCLIDES

CAPINTEC, INC. CAPRAC®-R

Use the ª arrow key to move the cursor to select OTHER. Press the ENTER key. Figure 8-3
Password Screen will appear.

PASSWORD

000

µ ¶ ´ to change
ENTER to accept

Figure 8-3 Password Screen

Use the © or ª and ¨ arrow keys to enter the password. When the correct password is
displayed, press the ENTER key. Figure 8-4 Other Setup Menu will appear.

f NUCLIDES
Ci/Bq
TRIGGER LEVEL
ACTIVITY CF
STD. SOURCE
RESET HV

Figure 8-4 Other Setup Menu

Use the ª arrow key to move the cursor to select ACTIVITY CF. Press the ENTER key.
Figure 8-5 Select Nuclide Screen will appear.

Nuclide:

I 131

CF key for generic
µ ¶ ´ to change
ENTER to accept

Figure 8-5 Select Nuclide Screen

Use the © or ª arrow keys to select the first letter of the radionuclide. Use the ¨ arrow key
to highlight the next letter. Repeat the process until the appropriate letter(s) and numbers
have been entered. If the nuclide name requires an ‘m’ after the number, use the ¨ arrow

8-2 USER-DEFINED NUCLIDES September 07

CAPINTEC, INC. CAPRAC®-R

key to move to the blank space after the number, then use the © arrow key to display the
‘m’. Press the ENTER key when the correct radionuclide name is displayed. Figure 8-6 User
Nuclide Screen will appear.

XE133
is not in memory

Use for USER NUCLIDE?

Yes(µ) or No(¶):

Figure 8-6 User Nuclide Screen

Press the ª arrow key if the name is not displayed correctly. Press the © arrow key to
confirm the addition of the new nuclide. Figure 8-7 Half-Life Units Screen will appear.

Half-life is in

f MINUTES
HOURS
DAYS
YEARS

Figure 8-7 Half-Life Units Screen

Use the © or ª arrow keys to select the appropriate unit for half-life. Press the ENTER key.
Figure 8-8 Half-Life Value Screen will appear.

Half-life value:

00.00D

µ ¶ ´ to change
ENTER to accept

Figure 8-8 Half-Life Value Screen

Use the © or ª arrow keys and the ¨ arrow key to input the correct half-life. The minimum
accepted value is .001; the maximum accepted value is 9999. If the half-life value does not

September 07 USER-DEFINED NUCLIDES 8-3

CAPINTEC, INC. CAPRAC®-R

fall within the accepted range, the message “INPUT ERROR – SEE MANUAL – ENTER TO
CONTINUE will be displayed.

Press the ENTER key when the correct half-life is displayed. Figure 8-9 User Nuclide
Screen will appear.

User Nuclide:
XE133
Half-life: 5.250 D

OK?

Yes(µ) or No(¶):

Figure 8-9 User Nuclide Screen

Press the ª arrow key to return to Figure 8-5 Select Nuclide Screen to make corrections;
press the © arrow key to confirm the information and add the user-defined nuclide to the
CAPRAC-R memory.

ADDING CF FOR USER-DEFINED NUCLIDE

The conversion factor for a user-defined nuclide may be added at the time the nuclide is
added to the CAPRAC-R memory, or at a later time. To add the conversion factor at a later
time, press the WIPE key to escape the screen.

To add the conversion factor for a new user-defined nuclide, the user must select either the
MEASURE (recommended) or INPUT from Figure 8-10 CF Menu.

f INPUT CF
MEASURE CF

Figure 8-10 CF Menu

Measure CF
To measure the conversion factor, use the ª arrow key to select MEASURE, then press the
ENTER key. Figure 8-11 Activity Unit Screen will appear.

8-4 USER-DEFINED NUCLIDES September 07

CAPINTEC, INC. CAPRAC®-R

CALIB ACTIVITY:
ACTIVITY IN

Ci
Bq

Figure 8-11 Activity Unit Screen

Calibration data can be entered in Curies or Becquerels:
Use the © or ª arrow keys to highlight the appropriate activity unit. Press the ENTER key.
Figure 8-12 Nuclide Calibrated Activity Screen will appear.

CALIB ACTIVITY:

0.0000 µCi

µ ¶ ´ to change
ENTER to accept

Figure 8-12 Nuclide Calibrated Activity Screen

Calibrate or obtain calibration information for the user-defined source, then using © or ª
arrow keys and the ¨ arrow key, input the activity.
Note: The calibrated activity should be in the range of 0.1-1.0 µCi (3.7-37 kBq).
When the activity has been entered correctly, press the ENTER key. Figure 8-13 Nuclide
Calibration Date Screen will appear.

CALIB DATE:

JUL 09 06

µ ¶ ´ to change
ENTER to accept

Figure 8-13 Nuclide Calibration Date Screen

September 07 USER-DEFINED NUCLIDES 8-5

CAPINTEC, INC. CAPRAC®-R

Use the © or ª arrow keys and the ¨ arrow key to input the correct date. When the correct
month, day and year is displayed, press the ENTER key. Figure 8-14 Nuclide Calibration
Time Screen will appear.

CALIB TIME:

12:00

µ ¶ ´ to change
ENTER to accept

Figure 8-14 Nuclide Calibration Time Screen

Using the © or ª arrow keys and the ¨ arrow key, input the correct time of calibration.

Note: The CAPRAC-R runs on a 24 hour clock. 9:30 a.m. is set as 09:30. 1:30 p.m. is set
as 13:30.

When the correct time is displayed, press the ENTER key. Figure 8-15 Calibration Data
Screen will appear showing the nuclide data entered.

XE133
.1080µCi

DEC 20 2006
08:45

OK?
Yes(µ) or No(¶):

Figure 8-15 Calibration Data Screen

If the information is not correct, press the ª arrow key and the system will return Figure 8-11
Activity Unit Screen.
If the displayed information is correct, press the © arrow key. Figure 8-16 Measure Nuclide
Source Screen.

8-6 USER-DEFINED NUCLIDES September 07

CAPINTEC, INC. CAPRAC®-R

MEASURE SOURCE

ENTER to Continue

Figure 8-16 Measure Nuclide Source Screen
Place the calibrated source in the detector and press the ENTER key. Figure 8-17 Nuclide
Counting Period Screen will appear.

20s

µ or ¶ to change
COUNT to Start

Figure 8-17 Nuclide Counting Period Screen

Use the © or ª arrow keys to set the number of seconds for the counting period. The five
choices for counting are 20, 60, 180, 600 and 1800 seconds.

When the correct time is displayed, press the COUNT key. Figure 8-18 Nuclide Count
Screen (Graph Display) will appear showing the number of counts in each of the CAPRAC-
R’s six channels. The remaining time and net number of counts (in cpm) will be updated
each second.

k 660 kcpm,n
e 400
V 200 0.39
40.70
100 49.20
61.40
39.36
80.43

Figure 8-18 Nuclide Count Screen (Graph Display)

September 07 USER-DEFINED NUCLIDES 8-7

CAPINTEC, INC. CAPRAC®-R

To change the screen format from Figure 8-18 Nuclide Count Screen (Graph Display) to
Figure 8-19 Nuclide Count Screen (Number Display), press the DISPLAY key.

29s

36.60kc
66.37kcpm

Figure 8-19 Nuclide Count Screen (Number Display)

Figure 8-19 Nuclide Count Screen (Number Display) shows net total counts (C) and the
combined net counts per minute (cpm) for the six CAPRAC-R channels.

At the end of the counting period, Figure 8-20 Channel Assignment Screen will appear.

´ to select channels

f CH 1 CH 4
CH 2 CH 5
CH 3 CH 6

ENTER when finished

Figure 8-20 Channel Assignment Screen

The Channel Assignment Screen allows the user to select the channel(s) to be used to
determine the conversion factor. Press the ª arrow key to move the cursor. Press the ¨

arrow key to select a channel. Shading indicates that the channel has been selected. The

cursor will automatically move to the next channel. Select the channels that correspond to

the gamma energy peaks for the newly added user-defined nuclide.

Channel Energy Range in keV

1 15 to 100
2 100 to 200
3 200 to 400
4 400 to 660
5 660 to 800
6 > 800

A recommended reference source for looking up gamma energy peaks is “Table of Nuclear-
Decay Data,” Appendix A.3 in A Handbook of Radioactivity Measurements Procedures

8-8 USER-DEFINED NUCLIDES September 07

CAPINTEC, INC. CAPRAC®-R

((NCRP Report No. 58), National Council on Radiation Protection and Measurements,
Bethesda, Maryland.

When the correct channels have been selected (highlighted), press the ENTER key. Figure
8-21 Nuclide CF Data Screen will appear.

XE133

CF: 1.46
CH: 1 2 3

OK?
Yes(µ) or No(¶):

Figure 8-21 Nuclide CF Data Screen

Press the © arrow key to accept the data, press the ª arrow key if the data is incorrect and
revisions are required.

Input CF
Capintec recommends that CF values be measured rather than input into the system;
however the CAPRAC-R program allows the user to input CF numbers.

To input a conversion factor for the user-defined nuclide, select INPUT CF from Figure 8-22
CF Menu

f INPUT CF
MEASURE CF

Figure 8-22 CF Menu
Press the ENTER key. Figure 8-23 Input CF Screen will appear.

September 07 USER-DEFINED NUCLIDES 8-9

CAPINTEC, INC. CAPRAC®-R

CONV. FACTOR
00.00

µ ¶ ´ to change
ENTER to accept

Figure 8-23 Input CF Screen

Use the © or ª arrow keys and the ¨ arrow key to input the correct conversion factor. Press
the ENTER key. Figure 8-20 Channel Assignment Screen will appear.

Note: The minimum accepted value is .001; the maximum accepted value is 9999.
Using the ª and ¨ arrow keys, select the appropriate channels for the radionuclide. Press
the ENTER key. Figure 8-21 Nuclide CF Data Screen will appear.

REPLACING A USER-DEFINED NUCLIDE WHEN THE MEMORY IS FULL

The CAPRAC-R can hold up to ten (10) user-defined nuclides. A user-defined nuclide cannot
be deleted from the system; however, they can be written over, or replaced, by a new user-
defined nuclide. .

To add an 11th user-defined nuclide:
• Press the WIPE and UTIL keys to return to the Main Utility Menu.
• Select SETUP, then press the ENTER key.
• Select OTHER, then press the ENTER key.
• Input the password, then press the ENTER key.
• Select ACTIVITY CF, then press the ENTER key.
• Enter the nuclide, then press the ENTER key.
• Press the © arrow key to answer ‘YES’ to the question as shown in Figure 8-24 User
Nuclide Screen.

IN113
is not in memory

Use for USER NUCLIDE?

Yes(µ) or No(¶):

Figure 8-24 User Nuclide Screen

8 - 10 USER-DEFINED NUCLIDES September 07

CAPINTEC, INC. CAPRAC®-R

If the CAPRAC-R user-defined memory is full, Figure 8-25 Write Over Screen will be
displayed.

No Room To Add
User Nuclide

Write Over a
User Nuclide?
Yes(µ) or No(¶):

Figure 8-25 Write Over Screen

To write over an existing user-defined nuclide, press the © arrow to answer ‘YES’. Figure 8-
26 Write Over Instruction Screen will appear.

Use ´ to indicate
Nuclide to Write Over

ENTER to continue

Figure 8-26 Write Over Instruction Screen

Press the ENTER key. Figure 8-27 User-Defined Nuclide List Screen will appear.

f XE133 GA67
CS129 AL26
I 130 AL28
CD109 IN115
AS77 IN116

Figure 8-27 User-Defined Nuclide List Screen

September 07 USER-DEFINED NUCLIDES 8 - 11

CAPINTEC, INC. CAPRAC®-R

Use the © or ª arrow keys to move the cursor. Press the ¨ arrow key to select a user-
defined nuclide to write over. Shading indicates that the nuclide has been selected. To erase
the shading, press the ¨ arrow key again.

When the appropriate nuclide to be written over has been selected, as indicated by shading,
press the ENTER key. Figure 8-7 Half-Life Units Screen will appear. Complete the
information as follows:

• Enter the nuclide’s half life, press the ENTER key.
• Enter the nuclide’s half-life value, press the ENTER key.
• Verify the nuclide data, press the ENTER key.
• Select INPUT CF or MEASURE CF, press the ENTER key.
• Enter the calibration activity, press the ENTER key.
• Enter the calibration date, press the ENTER key.
• Enter the calibration time, press the ENTER key.
• Verify the calibration data, press the ENTER key.
• Place the calibrated source in the detector, press the ENTER key.
• Set the counting period, press the COUNT key.
• Select the channels, press the ENTER key.

Note: To exit the program without writing over a nuclide, press the WIPE key. The user-
defined nuclides will remain unchanged.

8 - 12 USER-DEFINED NUCLIDES September 07


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