Johnson Matthey TRACERCO T401 User manual

TRACERCO T401
Contamination Monitor
USER MANUAL

Quality Assurance
Tracerco UK has accreditation for ISO9001 and ISO14001.
Confidentiality Notice
Information contained in this publication or as otherwise supplied to Users is believed to be accurate at time
of going to press and is given in good faith, but it is for the User to satisfy itself of the suitability of the Product
for its own particular purpose. Johnson Matthey plc (JM) accepts no liability for loss or damage (other than that
arising from death or personal injury caused by JM’s negligence or by a defective Product, if proved) resulting
from reliance on this information. Freedom under Patent, Copyright and Designs cannot be assumed.
Copyright © 2017 Tracerco Ltd. All rights reserved.

Table of Contents
1General Description.................................................................................................................................... 5
2Operational Safety...................................................................................................................................... 6
3Post Delivery Checks ................................................................................................................................. 7
4Operational Features.................................................................................................................................. 8
4.1 Switch On............................................................................................................................................8
4.2 Speaker...............................................................................................................................................8
4.3 Backlight .............................................................................................................................................8
4.4 Low Battery.........................................................................................................................................8
4.5 Pre-Set Alarm .....................................................................................................................................8
4.6 Detector Probe....................................................................................................................................9
4.7 Calibration...........................................................................................................................................9
5Measurement of Radiation Contamination............................................................................................... 10
5.1 Procedure .........................................................................................................................................10
5.2 Bargraph Display..............................................................................................................................10
5.3 Digital Numeric Display.....................................................................................................................10
5.4 Peak Display.....................................................................................................................................10
5.5 Mode / Select....................................................................................................................................10
5.6 Nuclide Calibration Selection............................................................................................................11
5.7 Carry Out a “Background” Count ......................................................................................................11
5.8 Carry Out a “Nuclide Measurement”.................................................................................................12
5.9 Nuclide Options ................................................................................................................................13
5.10 Operational Ranges..........................................................................................................................14
5.10.1 T401 Functional Diagram ........................................................................................................ 14
5.11 Setting Alarm Trip Levels..................................................................................................................15
5.11.1 Sounder Options...................................................................................................................... 15
5.11.2 Setting the Alarm Trip Level .................................................................................................... 16
6Detector Probe ......................................................................................................................................... 17
6.1 Probe Retained in Monitor Yoke.......................................................................................................17
6.2 Remote Probe / Yoke Assembly.......................................................................................................17
6.3 Remote Probe with Telescopic Extension Kit...................................................................................17
7Maintenance and Calibration.................................................................................................................... 18
7.1 Battery Replacement ........................................................................................................................18
7.2 General Maintenance .......................................................................................................................18

7.3 Repair and Calibration......................................................................................................................19
7.3.1 Calibration Plaques...................................................................................................................... 19
8Technical Specification............................................................................................................................. 20
9Monitor Response .................................................................................................................................... 21
9.1 Affects of Gamma Radiation.............................................................................................................21
10 Hints for Radiation Contamination Monitoring.......................................................................................... 22
11 Health and Safety..................................................................................................................................... 23
11.1 Training.............................................................................................................................................23
11.2 Battery life.........................................................................................................................................23
11.3 Probe ................................................................................................................................................23
11.4 Radiation reading..............................................................................................................................23
11.5 Alpha radiation...............................................................................................................................23
Revision History............................................................................................................................................... 25

1 General Description
The Tracerco T401 is a portable battery operated radiation contamination monitor, capable of
measuring alpha, beta and gamma radiation over a wide range of energies. Radiation detection is
carried out using a thin window Geiger Muller Tube located in a detachable probe adjacent to the head of
the monitor.
Tracerco has extensive experience of the practical difficulties which may be encountered when
attempting to carry out contamination monitoring of both man-made and naturally occurring
radioactivity under hostile and restrictive environmental conditions, particularly those which relate to
the Chemical, Mining, Nuclear and Oil and Gas Industries.
The Tracerco T401 has been designed to address many of these practical issues in providing a
monitor which is reliable, versatile, easy to use and capable of operating in adverse environmental
conditions.
A key feature of the Tracerco T401 is the capability to allow pre-programming of detection efficiency
data for a wide range of radionuclides enabling recorded counts/sec to be automatically translated
into more radiologically significant units of Bq/cm
2
. There are additional design elements which are
fully described in this manual and combine to make the T401 an invaluable instrument for use in
radiation contamination monitoring.

2 Operational Safety
The Tracerco T401 Contamination Monitor is a portable battery operated device which has been designed
to exacting standards to operate reliably in adverse environments.
Typical battery life is around 100 hours. A ‘LO BATT’ warning appears on screen when the residual
capacity reduces to about 4 hours. When the residual charge is exhausted, the screen clears.
A selectable backlight facility allows measurements to be made under dark or low light conditions.
(Note that the extended use of this function will significantly reduce battery life).
An audible response is also available to complement visual measurements.
In the event of a GM tube failure or circuit malfunction which interrupts the radiation detection
signal, the screen will indicate the following warning message “ERR1”.

3 Post Delivery Checks
All monitors supplied by Tracerco have been fully inspected, tested and calibrated prior to shipping. The
monitor will be fitted with a new battery and available for immediate operation.
Each monitor is supplied in a protective overpack for transportation (customers may purchase an
alternative, special transport and storage case).
All monitors should reach the customer in perfect working order.
In the unlikely occurrence of a problem, please contact Tracerco immediately (contact numbers are
provided within this manual).
PLEASE ENSURE THAT THE MONITOR RADIATION TEST AND CALIBRATION
CERTIFICATE IS PRESENT IN THE PACK. (Certificates should be filed in a safe place for future
reference. In the event of difficulties, duplicate certificates can be provided by Tracerco free of
charge, they are also available on our webtracker.

4 Operational Features
Owners should also refer to the Main Menu Structure for Functionality
4.1 Switch On
The monitor is activated by pressing the RED on / off switch. This switch has a toggle action –press for
ON and press again for OFF .In the absence of any significant local radiation sources the meter will
register incident background radiation which will vary with geographical location. A typical background
reading on the monitor would be of the order of 0.5 –1 count per second.
Please note that there may be a slight delay of one or two seconds between physically operating the
switch and the screen clearing of information.
4.2 Speaker
Pressing the GREY switch with the speaker symbol activates the internal speaker. The speaker provides
an audible clicking sound whose rate is proportionate to the amount of radiation registered by the
detector.
The speaker may be silenced by re-pressing the GREY switch. The speaker symbol shows on
screen when the audible option has been selected. Battery life is extended with the speaker off.
4.3 Backlight
The monitor display is fitted with a backlight, which is available for use in situations of low ambient light
intensity. The GREY switch with the sunburst symbol is pressed to activate the backlight facility. Since the
backlight significantly increases the current drain on the battery, the pushbutton switch is designed for
contact operation only ie., depressing the switch activates the backlight and releasing the switch cancels
the light.
4.4 Low Battery
The monitor is equipped to display a “LO BATT” message. Although it is recommended that the battery be
replaced as soon as this message is activated, it might be expected that under normal conditions, the
monitor is capable of operating for a further 4 hours.
4.5 Pre-Set Alarm
The monitor is equipped with an alarm function which the operator can pre-set, within prescribed
limits, to any desired level of counts per second ( cps ) or Bq/cm
2
. If an alarm level is set in the cps mode,
it will not be available when in the Bq/cm
2
mode (and vice versa). An alarm is a continuous high
frequency tone whenever the measured reading exceeds the pre-set value. The alarm may be
deactivated by the operator. There is no mute (accept facility) for the alarm. Alarm activation is indicated
by a flashing loudspeaker icon.

4.6 Detector Probe
The T401 Contamination Monitor is equipped with a thin window Geiger Muller detector located in a special
probe attached to the head of the monitor. The detector has the capability to measure alpha, beta and
gamma radiation over a wide range of energies and its delicate, recessed front window is protected by an
open mesh steel grille during use. (Although the mesh provides protection from a rupture of the thin
window by large objects during use, the window remains delicate and vulnerable to puncture by thin
sharp objects and care should be exercised at all times when carrying out monitoring operations).
The detector probe normally rests within a special yoke attached to the monitor, with the face of the probe
orientated into and protected by the main body of the monitor. This orientation is recommended
during storage or transportation. The probe is connected to the monitor via a flexible cable which
is normally retained within the horseshoe-shaped skid attached to the monitor.
The probe is designed to be used in three possible ways during monitoring operations:-
Probe remains attached to the monitor yoke but rotated to suit monitoring requirements.
Probe and the yoke are decoupled from the body of the monitor for hand operation. The
flexible cable allows remote operation up to 1.5-metres from the body of the monitor.
Probe and yoke are removed from the body of the monitor and attached to the
extendable arm (purchased option). The orientation of the probe is adjustable relative to the
extension arm to provide maximum flexibility when monitoring. (Further information on these
monitoring options is provided in section 6 describing the detector probe).
4.7 Calibration
Current UK legislation requires that all operational radiation monitors are subject to annual inspection and
testing. This requirement includes for performance checks and where appropriate, recalibration of
the monitor.
The calibration due date will be displayed on a label attached to the monitor. This date will indicate
the 12-month anniversary of the current calibration. This can be added to appear on the monitor
screen during start up if requested on purchase or when calibrating the monitor; then when switching
on the contamination monitor, the next calibration check due date will register automatically on
the screen for approximately 2 seconds.
All Tracerco radiation monitors are checked and calibrated immediately prior to despatch to the
customer. Following this initial procedure (or the annual inspection and calibration check), Tracerco
operatives will re-set the next calibration check due date within the software of the monitor.
For further information on the calibration procedure refer to sections 7.3 and 9.

5 Measurement of Radiation Contamination
5.1 Procedure
Switching on the monitor will display all available segments for approximately 2 seconds (as shown below).
A check should be performed for any missing segments.
For the following 2 seconds, the next ‘Cal Due’ date will show using a MM-YY format. The monitor then
enters normal operation (cps mode).
5.2 Bargraph Display
This display provides a reading in the range 0cps –1000 cps. Maximum resolution is provided in the
range 0 –10cps, which is considered to be the most critical range for routine waste characterisation
purposes.
If the probe is exposed to activity levels which exceed the maximum count rate of 1000 cps, the
bargraph will remain at full scale deflection until the source of radiation is removed.
5.3 Digital Numeric Display
There is a 5 digit digital display. For radiation levels below 100cps or 100 Bq/cm
2
the monitor will
give a reading to 2 decimal places. The maximum indication is 4000 cps or its equivalent in Bq/cm
2
5.4 Peak Display
The meter is capable of numerically indicating the highest radiation level to which the probe has been exposed
since the instrument was switched on. Switching off will clear this reading.
Pressing the green“ PEAK ”button will show this reading. (During this period peak value continues to
be updated). A second press of the “PEAK” button during this period will return monitor to normal
function.
Pressing“ SELECT / RESET ”button whilst displaying the peak reading will reset the peak reading to
zero.
5.5 Mode / Select
The yellow“ MODE ”and green“ SELECT / RESET ”buttons are required when accessing various functions
associated with the monitor.