ANSI N42.33 pdf free download

ANSI N42.33 pdf free download.Portable Exposure Rate Meters for Homeland Security.
6.1.2 Test method
Switch the instrument on and place it in an environmental chamber at a temperature of 22 °C ± 2 °C.
Expose the instrument to a ‘37Cs gamma source. Collect 10 independent readings and calculate the mean reading, standard deviation, and coefficient of variation. Increase the exposure rate andlor the number of readings as needed to obtain a COV value that is 12%.
NOTE—If the instrument has an audible alarm, it is acceptable to increase the alarm threshold to prevent an alarm due to the exposure rate used for testing.
Allow the chamber and instrument to stabilize at 22 °C for I h. During the last 15 mm of the stabilization period, collect a series of readings and determine the mean instrument response, standard deviation, and coefficient of variation.
Increase the temperature in the chamber at a rate of 10 °C per hour to +50 °C. The relative humidity level within the chamber should be kept below 75% to prevent condensation. At each 10 °C (30 °C and 40 °C) increment, stabilize the temperature for a period of 1.5 h. During the last 15 mm of each stabilization period, collect a series of readings and determine the mean instrument response.
At the high temperature limit of +50 °C, the instrument shall be exposed for a period of 4 h with readings recorded during the last 15 mm of the 4 h period.
This same process shall be performed for temperatures that arc less than the reference temperature of 22 °C. The 10 °C intenals are 10 °C, 0 °C, and —10 °C and the lower temperature limit is —20 °C. The test at —20 °C shall be the same as that performed at +50 °C.
The instrument is acceptable if the mean reading at each test point is within ±15% of the mean reading obtained at 22 °C. No alarms or malfunctions shall occur due to temperature.
6.2 Temperature shock
6.2.1 Requirement
The instrument shall be fully functional within 2 mm of exposure to rapid temperature changes from 22 °C to —20 °C, —20 °C to 22 °C, 22 °C to 50 °C, and 50 °C to 22 °C with each change being made in less than 5 mm. Relative humidity shall be within the range of standard test conditions specified in Table 1.
6.2.2 Test method
Switch the instrument on, place it in an environmental chamber.
Expose the instrument to a ‘37Cs gamma source. Collect 10 independent readings and calculate the mean reading, standard deviation, and coefficient of variation. Increase the exposure rate or number of readings as needed to obtain a COV value that is l2%.
NOTE—If the instrument has an audible alarm, it is acceptable to increase the alarm threshold to prevent an alarm due to the exposure rate used for testing.
Allow the chamber and instrument to stabilize at 22 °C for 1 h.
During the last 15 mm of the stabilization period, collect a series of readings and determine the mean instrument response, standard deviation, and coefficient of variation.ANSI N42.33 pdf download.