ANSI N42.35:2006 pdf download.Evaluation and Performance of Radiation Detection Portal Monitors for Use in Homeland Security.
3.1.8 calibrate: To adjust andior determine the response or reading of a device relative to a series of conventionally true values.
3.1.9 calibration: A set of operations under specified conditions that establishes the relationship between values indicated by a measuring instrument or measuring system and the conveniionally true values of the quantity or variable being measured.
3.1.10 check source: A not-necessarily calibrated source that is used to confirm the continuing functionality of an instrument.
3.1.11 coefficient of variation (COV)(%): The square root of the variance, 2• divided by the mean value of”n number of readings times 100.
3.1.12 conventionally true value (CTV): The commonly accepted best estimate of the value of that quantity.
NOTE This and the associated uncertainty will preferably be determined by a national or transfer standard, or by a reference instrument that has been calibrated against a national or transfer standard, or by a measurement quality assurance (MQA) interaction with the National Institute of Standards and Technology (NIST) or an accredited calibration laboratory. (Sec ANSI N42.22 and ANSI N42.23.)’
3.1.13 decade: A range of values for which the upper value is a power often above the lower value.
3.1.14 detection limits: The extremes of detection or quantification for the radiation of interest.
NOTE—The lower detection limit is the minimum statistically quantifiable instrument response or reading. The upper detection limit is the maximum level at which the instrument meets the required accuracy.
3.1.15 detector: A device or component designed to produce a quantifiable response to ionizing radiation normally measured electronically.
3.1.16 effective center: For a given set of irradiation conditions, the point within a detector where the response is equivalent to that which would be produced if the entire detector were located at the point.
3.1.17 effecth’e range of measurement: Range of measurements within which the requirements of this standard are met.
3.1.18 energy dependence: Variation in instrument response as a function of radiation energy for a constant radiation type and exposure rate referenced to air.
3.1.19 exposure rate: The measure of ionization produced in air by x-ray or gamma-ray radiation. NOTE—The special unit of exposure rate is the Roentgen per hour, abbreviated in this standard as Rh.
NOTE—In this standard, the International System (SI) Linits sieved (Sw) or gray (Gy) follow in parentheses the Rocnueii value R, though the two units are not physically equiaIent.
3.1.20 false alarm: Alarm NOT caused by a radioactive source under the specified background conditions.
3.1.21 functional check: A frequently used qualitative check to determine that an instrument is
operational and capable of performing its intended function.
NOTE—Such cheeks may include, for example. battery check, zero setting. or source response check.
3.1.22 indicated value: (A) A scale or decade reading. (B) The displayed value of the readout. See also:
reading.
3.1.23 indication: Displayed signal from the instrument to the user conveying information such as scale or decade, status, malfunction or other critical information.
3.1.24 influence quantity: Quantity that may have a bearing on the result of a measurement without being the subject of the measurement.
3.1.25 innocent alarm: An alarm resulting from an actual increase in radiation level, but for reasons that
arc not due to the detection of illicit radioactive materials.
NOTE Also called a nuisance alarm.
3.1.26 instrument: A complete system consisting of one or more assemblies designed to quantify one or more characteristics of ionizing radiation or radioactive material.
3.1.27 instrument hour: That period of time that the instrument is powered on and operating.
NOTE The number of operating instruments multiplied by the amount of time they are operating (e.g.. eight instruments operating for 3.75 h is equivalent to 30 instrument hours).
3.1.28 interdiction: Stopping the illicit or inadvertent movement of radioactive material that has been discovered as a result of radiation detection or measurement.
3.1.29 monitoring: Means provided to continuously indicate the state or condition of a system or assembly.
NOTE—May also be used for the real time mcasuremeni of radioactivity or radiation levels.
3.1.30 over-range response: The response of an instrument when exposed to radiation intensities greater than the upper detection limit.
3.1.31 performance test: An evaluation of the performance of an instrument in response to a given influence quantity.
3.1.32 Point of measurement: Place where the conventionally true values are determined and where the reference point of the instrument is placed for lest purpoSes.
3.1.33 precision: Degree of agreement of repeated measurements of the same paramctcr
3.1.34 range: All values lying between the lower and upper detection limits.
3.1.35 reading: The indicated or displayed value of the readout.
3.1.36 readout: The portion of the instrument that provides a visual display ot Lhe response oi the instrument or the displayed value, with units, displayed and/or recorded by the instrument as a result of the instrument’s response to some intluence quantity.
