IEC 60761-5 pdf download Equipment for continuous monitoring of radioactivity in gaseous effluents – Part 5: Specific requirements for tritium monitors
lf the detection assembly includes an absorbent medium，intended to collect a specificchemical form of tritium，its characteristics,efficiency,retention capacity and delay timeconstant shall be known for the various radioactive gases of significance in the effluent.
The manufacturer shall state how the collection efficiency is influenced by the chemical form oftritium，atmospheric conditions and the presence of chemical products and other gases insampled air.The manufacturer shall specify the storage conditions of the absorbent medium.
Any check source, when not in use, shall not increase the reading of the measurement assemblyby more than 10 % of the maximum value of the lowest useful decade of measurement.
The requirement of clause 11 of lEC 60761-1 is applicable.5.7 Radiation detector
The manufacturer shall specify the detector characteristics，including the detector dimensionsand sampling volume.
6 Expression of measurements
ln accordance with the requirements of clause 9 of lEC 60761-1,the electronic assemblyassociated with the detector shall provide a reading expressed directly in terms of volumicactivity (Bq/m3).
7 Tests performed under standard test conditions
Except where otherwise specified, tests are to be considered as type tests,although any or allmay be considered as acceptance tests by agreement between manufacturer and purchaser.
The standard test conditions are shown in Table 1.These represent the values and tolerancesof the various influence quantities for tests carried out with no variation of these values.
The tests carried out under standard test conditions are listed in Table 2.
8Tests performed with variation of the influence quantities
These tests are listed in Tables 3 and 4.They shall be carried out in accordance with clause 24of lEC 60761-1.
9 Reference sources
For the determination of the reference response during type tests, the reference source shallbe air with a known volumic activity of the particular form of tritium for which the equipment isdesigned.The reference sources should consist of bottles of pressurized air or gas containingthe form of tritium for which the equipment is designed or any other calibrated devicegenerating the appropriate form of tritium.
Some suitable means of producing sources are described in annex A.The conventionally trueactivity of the gas sources shall be known with an uncertainty better than 7 %(k = 2).
10 Radiation performance tests
These tests are carried out under standard test conditions. lf an electronic method ofcompensation against natural activity is included, all tests of the measuring assembly shall beperformed with the compensation circuits in operation, after having been adjusted according tothe manufacturer’s instructions.