MALB_2014 with 1-21 Revisions

Conducting Measurements of Radon and Radon ANSI/AARST MALB-2014 with 1/21 Revisions Decay Products in Schools and Large Buildings 35 9.10 Clearance Testing A test procedure for obtaining evidence that radon concentrations in all dwellings and occupied areas of a building are below the predefined action level . 9.11 Client The individual(s) or parties who hire(s) or pay(s) for radon test services. 9.12 Collocated Two or more simultaneous measurements within 4-8 inches (10-20 cm) of each other in the same location, or side-by-side. 9.13 Comparison Checks Collocated , simultaneous measurements conducted for the purpose of assessing and monitoring measurement reliability. Comparison checks include but are not limited to duplicate measurements that are defined as collocated , simultaneous measurements using measurement devices of the same manufacturer, model, and most recent calibration date and facility. 9.14 Conditioned Space Areas within the heated and cooled envelope of the building where HVAC systems maintain temperatures to facilitate comfort of occupants. Basement areas that maintain occupiable temperatures by virtue of ambient sources of heat or cooling, such as from the earth or adjoined air spaces are considered conditioned spaces within the heated and cooled envelope of the building. 9.15 Continuous Radon A CRM is an electronic device that is capable of automatically recording a Monitor (CRM) retrievable time series of numeric measurements of radon concentration averaged over time intervals of 1 hour or less. If a device is not capable of these functions or is not set to record readings each hour, it is functioning as a passive device and is not considered a continuous monitor under this protocol. 9.16 Crawl Space An open area beneath part or all of the livable space of a dwelling that typically has either a concrete slab or dirt floor. The dirt floor may be covered with gravel or a membrane. The crawl space can have an open height of a few inches to several feet. The crawl space can be storage space but is not living space. 9.17 Duplicates Collocated , simultaneous measurements conducted with instruments or devices that are identical (including manufacturer, model, and, for continuous monitors, the samemost recent calibration facility and schedule) for the purpose of assessing and monitoring the measurement system imprecision. (See Comparison Check for a different category of QC measurements that do not require the use of identical devices.) 9.18 Dynamic Equilibrium: The state where radon and dilution air entering a building have reasonably stabilized under closed-building conditions. Buildings are generally closed more than 70% of the year and 12 hours is usually sufficient for dynamic equilibrium to occur in most buildings. 9.19 Economizer Systems An HVAC systems that provides additional outside air to a building in variable volumes, depending on outdoor temperature, as a means to save expenses of operating air conditioning equipment. 9.20 Electret Ion Chamber This type of device uses an ion chamber made of, or lined with, an electrically (EIC) Method: conductive material with an electret as the detecting mechanism. The surface voltage of the positively charged electret is measured before and after the exposure to radon . During the exposure, radon passively diffuses into the ion chamber and subsequently decays. The radon decay and its short-lived progeny ionize the air inside the chamber. Electrons are attracted to the electret and discharge it. From the surface voltage of the electret measured before and after the exposure, and the duration of the exposure, the average radon concentration during the exposure can be calculated using calibration factors determined through exposures of devices in