The minimum required number of sample cassettes for each enclosure site is listed in the tables below (each set of samples consists of inside samples, ambient air samples, field blanks, and a sealed blank):
Inside Sample Cassettes | ||
Square Feet of Enclosure | PCM Analysis | TEM Analysis |
less than 100 | 2 | 5 |
100-500 | 3 | 5 |
500-1000 | 4 | 5 |
1000-10,000* | 5 | 5 |
Ambient Sample Cassettes | ||
Square Feet of Enclosure | PCM Analysis | TEM Analysis |
less than 100 | 0 | 5 |
100-500 | 0 | 5 |
500-1000 | 0 | 5 |
greater than 1000 | 0 | 5 |
* For areas greater than 10,000 square feet, the number of inside air samples to be obtained will increase by one sample for each 5,000 square feet over 10,000 square feet. For example, using TEM an enclosure of 30,000 square feet would require nine inside samples, five ambient air samples, two field blanks, and one sealed blank, for a total of 17 samples in the set.
The run time for each air pump is calculated by dividing the flow rate (lpm) of the pump into the number of liters of air required to be collected (1,000 liters minimum for PCM analysis, 1,199 liters minimum for TEM analysis) to obtain the required number of minutes.
A floor plan indicating the locations of the collected sample cassettes, along with a data sheet indicating the project name, project monitor, location of project, date samples were collected, calibrated flows for each air pump, start and stop times for each air pump, the preferred method of analyses specified, and the calculated number of liters drawn for each cassette sample, shall be transmitted to the laboratory with the cassette samples to be analyzed. The inclusion of these documents is necessary when generating reports on final clearance air sampling for the project.
Air sample cassettes shall be shipped in separate containers from bulk samples. To prevent sample cassette contamination, avoid using expanded polystyrene because of its static charge and particle-based packaging materials.
1 Va. Admin. Code § 30-110-60
Statutory Authority
§ 2.1-526.14 of the Code of Virginia.