Illinois Administrative Code › Title 32 - ENERGY › Part 422 - REGULATIONS FOR RADON SERVICE PROVIDERS › Section 422.140 - Device Protocol

Current through Register Vol. 48, No. 28, July 12, 2024
a) Quality
			 Assurance
1) Professional licensees providing
			 measurement services using radon and radon product measurement devices shall
			 establish and maintain a Quality Assurance Program (QAP). These programs shall
			 include written procedures for attaining quality assurance objectives and a
			 system for recording and monitoring the results of the quality assurance
			 measurements for each device used. The QAP shall include the maintenance of
			 control charts and related statistical data.
2) The objective of quality assurance is to
			 ensure that data are scientifically sound and of known precision and accuracy.
			 This subsection (a)(2) discusses the 6 general categories of quality control
			 measurements. Specific guidance is provided for each method in the relevant
			 protocol.
A) Calibration Measurements.
			 Calibration measurements are samples collected or measurements made in a known
			 radon environment, such as a radon chamber. Instruments providing immediate
			 results, such as continuous working level and radon monitors, shall be operated
			 in a radon chamber to establish individual instrument calibration factors.
i) Calibration measurements must be conducted
			 to determine and verify the conversion factors used to derive the concentration
			 results. These factors are determined normally for a range of concentrations
			 and exposure times, and for a range of other exposure and/or analysis
			 conditions pertinent to the particular device.
ii) Determination of these calibration
			 factors is a necessary part of the laboratory analysis and is the
			 responsibility of the laboratory. These calibration measurement procedures,
			 including the frequency of tests and the number of devices to be tested, shall
			 be specified in the QAP maintained by manufacturers and analysis
			 laboratories.
iii) Licensees
			 providing measurements with active devices are required to recalibrate their
			 instruments at least once every 12 months.
B) Known Exposure Measurements (Spikes).
			 Known exposure measurements or spiked samples consist of detectors that have
			 been exposed to known concentrations in a radon chamber. These detectors, such
			 as charcoal canisters, alpha track detectors and electret ion chambers, are
			 labeled and submitted to the laboratory in the same manner as ordinary samples
			 to preclude special processing.
i) Suppliers
			 and analysis laboratories shall provide for the blind introduction of spiked
			 samples into their measurement processes and the monitoring of the results in
			 their QAP.
ii) Licensees using
			 passive monitorsshall conduct spiked measurements (i.e., exposure in a radon
			 chamber where the environmental radon level is controlled) to aid the Agency in
			 verifying the accuracy of the entire measurement system. The licensee shall
			 conduct 3 spiked measurements per 100 measurements, with a minimum of 3 spiked
			 measurements per year. For example, a licensee conducting only 70 measurements
			 in a year must conduct at least 3 spiked measurements. A licensee conducting
			 500 measurements during a one-year period must conduct at least 15 spiked
			 measurements (3 per each 100). No more than 6 spiked measurements will be
			 required to be taken within any single month. For example, a licensee
			 performing more than 200 measurements in one month is not required to perform
			 more than 6 spiked measurements that month. Licensees are encouraged to take
			 their spiked measurements from multiple batches when possible and to take more
			 than the minimally required spiked measurements at their discretion. Devices
			 shall be exposed in a radon chamber at a minimum of 3 different radon
			 concentrations, such as approximately 4.0, 10-30 and 30-100 pCi/L.
iii) Spikes shall be labeled in the same
			 manner as field detectors to ensure identical processing. The results of
			 analyses of detectors exposed to known radon concentrations shall be monitored
			 and recorded. Any significant deviation from the known concentration to which
			 they were exposed shall be investigated and corrective action taken.
C) Background Measurements.
			 Background measurements are required both for continuous monitors and for
			 passive detectors requiring laboratory analysis.
i) Licensees using continuous monitors shall
			 perform sufficient instrument background measurements to establish a reliable
			 instrument background and to act as a check on instrument operation.
AGENCY NOTE: Calibration laboratories routinely perform
				background measurements of continuous monitors during the calibration of
				instruments.
ii) Passive
			 detectors requiring laboratory analysis require one type of background
			 measurement made in the laboratory and another in the field.
iii) Laboratories shall measure the
			 background of a statistically significant number of unexposed detectors from
			 each batch or lot to establish the laboratory background for the batch and the
			 entire measurement system. This laboratory blank value is subtracted (by the
			 laboratory) from the field sample results reported to the user, and shall be
			 made available to the users for quality assurance purposes.
iv) Laboratories performing these
			 measurements shall calculate the lower limit of detection (LLD) for their
			 measurement systems. This LLD is based on the detector and analysis system's
			 background and can restrict the ability of some measurement systems to measure
			 low concentrations.
v) Licensees
			 using passive detectors shall employ field controls (called blanks) equal to
			 approximately 5 percent of the detectors that are deployed, or 25 each month,
			 whichever is smaller.
vi) These
			 controls shall be set aside from each detector shipment, kept sealed and in a
			 low radon environment, labeled in the same manner as the field samples to
			 preclude special processing, and returned to the analysis laboratory along with
			 each shipment. These field blanks measure the background exposure that may
			 accumulate during shipment and storage. The results shall be monitored and
			 recorded.
vii) The recommended
			 action to be taken if the concentrations measured by one or more of the field
			 blanks is significantly greater than the LLD is dependent upon the type of
			 detector and is discussed in the protocol for each method.
D) Duplicate Measurements. Duplicate
			 measurements provide a check on the precision of the measurement result and
			 allow the user to make an estimate of the relative precision. Large precision
			 errors may be caused by detector manufacture or improper data transcription or
			 handling by suppliers, laboratories, or technicians performing placements.
			 Precision error can be an important component of the overall error; therefore,
			 licensees performing measurements shall monitor precision.
i) Duplicate measurements shall be
			 side-by-side measurements made in at least 10 percent of the total number of
			 measurement locations, or 50 each month, whichever is smaller. The locations
			 selected for duplicate measurement shall be distributed systematically
			 throughout the entire population of samples.
ii) The precision of duplicate measurements
			 shall be monitored and recorded in the quality assurance records. The analysis
			 of data from duplicates shall be plotted on range control charts. If the
			 precision estimated by the user is not within the precision expected of the
			 measurement method, the cause of the problem shall be investigated.
iii) Detectors shall be treated identically
			 in every respect. They shall be shipped, stored, opened, installed, removed and
			 processed together, and not identified as duplicates to the processing
			 laboratory.
E) Routine
			 Instrument Performance Checks. Proper functioning of analysis equipment and
			 operator usage require that the equipment and measurement system be subject to
			 routine checks. Regular monitoring of equipment and operators is vital to
			 ensure consistently accurate results. Performance checks include the frequent
			 use of an instrument check source. Components of the device (such as a pump,
			 battery or electronics) shall be checked regularly and the results noted in a
			 record. Each user shall develop methods for regularly monitoring (preferably
			 daily with use) their measurement system and for recording and reviewing
			 results.
F) Cross-checks.
			 Professional licensees using active monitors shall check their monitors for
			 bias on a regular basis. Ideally, such measurements are made in a radon
			 chamber. Exposure in a radon chamber is required during calibration. It can be
			 difficult to expose active monitors more often than once every 12 months. It is
			 important to more frequently assess the continued satisfactory operation of the
			 instrument response and to ensure damage from shipping has not occurred prior
			 to an instrument being placed into service after calibration. Cross-checks
			 shall be performed prior to placing an instrument being returned to service
			 after calibration and at 6 months (plus or minus a month) after calibration.
			 The following conditions shall be met:
i)
			 Where feasible, a cross-check shall begin with an instrument background
			 measurement.
ii) The cross-check
			 measurement shall be made in an environment that has been chosen for its
			 stability and radon concentration that is above the lower limit of
			 detection.
iii) Cross-checks shall
			 be side-by-side measurements.
iv)
			 One of the instruments shall have been calibrated within the last 45
			 days.
v) A measurement of at least
			 48 hours duration shall be conducted.
vi) The bias of cross-check measurements
			 shall be monitored and recorded in the quality assurance records. If the bias
			 estimated by the user is not within the bias expected of the measurement, the
			 cause of the problem shall be investigated and corrective action taken in
			 accordance with the licensee's Agency-approved QAP.