Johnson Matthey TRACERCO T401, User Manual, Page: 19 / 26

7.3 Repair and Calibration
The Tracerco T401 instrument incorporates special software for checking and calibrating the response of the
monitor to incident radiation.
In order to comply with UK statutory regulations, the monitor must be inspected and tested on at
least an annual basis. It is recommended that such inspection and testing is carried out by Tracerco
or an approved organisation which has access to the appropriate testing equipment and diagnostic
software.
The Tracerco T401 monitor has been designed as a sealed unit, whereby all essential operating
parameters have been optimised and set at the time of manufacture and during tes t and calibration
procedures. These controls are not accessible to the customer and should not require any
adjustments during normal operation.
In addition to checking the physical condition of the monitor, Tracerco will check the response of the monitor
to the displayed radionuclides using special plaques whose radioactivity content per unit area of surface is
traceable to recognised national standards. Tracerco will consider modifying the list of calibration
nuclides, where the operator has a specific requirement and appropriate calibration materials can
be sourced.
Battery replacement will be a standard element of this annual inspection procedure.
7.3.1 Calibration Plaques
Where possible calibration data supplied for the Tracerco T401 Contamination Monitor has been measured
using large surface area reference plaques. These plaques comply with the requirements for
traceability to NIST specified in the ‘American National Standard Traceability of Radioactive
Sources to the N IST and Associated Instrument Quality Control (ANSI N42.22-
1 995)’.
These plaques are constructed such that the radionuclides of interest are incorporated into the
surface of an anodised aluminium foil of 0.3mm thickness. The thickness of the activated la yer
is approxim ately 6
µ
m . In accordanc e with ISO8769, the calibration plaques are designated as Class
2 Reference Sources.