Test Procedure cont'd - doe-std-1167-20030026

DOE-STD-1167-2003

17.1.2 Noise measurements should be conducted with Type I or Type II sound level

meters equipped with omni directional microphones using the A-weighted

network and the slow-response setting. Sound level meters should be

calibrated following the manufacturer's recommendations. Prior to and

immediately after completing sound level testing, the accuracy of sound level

meters should be verified following the manufacturer's recommendations

using a source recommended by the manufacturer. Calibration and accuracy

checks should be incorporated into the test report.

17.1.3 The sound level meter should have the microphone attached using a

manufacturer's recommended extension cable to permit the microphone to be

remote from the display unit.

17.1.4 A device to hold the remote microphone within three inches of either ear of

the suit tester while not affecting the normal operation of the suit should be

used. The device is only required for testing the supplied-air suit noise levels,

and if desired, may be eliminated during other evaluations. The reading on

the Sound Pressure Level Meter can be affected by the diaphragm of the

microphone in the direct airflow path of the inlet air, or if it is incident to the

airflow path. When directly in the path it could result in an artificially high

reading and when at a 90-degree angle to the path (if the velocity is great

enough) it can result in an artificially low reading. Therefore, the test

operator should take care to assure that the microphone is placed near the suit

tester's ear, but not in or incident to the airflow path.

17.1.5 Airflow measuring equipment should be capable of determining the volume

of air entering the supplied-air suit with an accuracy of plus or minus 10

percent. Calibration information should be incorporated into the test report.

17.1.6 Prior to a suit tester donning the supplied-air suit the test operator should

confirm that the noise level inside the helmet is less than 85 dBA and

determine whether noise levels are uniformly distributed within the helmet. If

the helmet noise levels equals or exceeds 85 dBA, testing should not continue

without concurrence from the ERAP administrator. If the noise levels are not

uniformly distributed, the in-helmet microphone should be positioned near

the ear expected to experience the greatest noise. The test operator should

attach the device containing the remote microphone to the suit tester, and

ensure that the microphone is located within three inches of the suit tester's

right or left ear except as noted above. The suit tester should don the

supplied-air suit in accordance with instructions provided by the DOE

contractor.

17.2

Test Procedure

17.2.1 The test operator should measure the background noise in the helmet with no

air flowing into the supplied-air suit. While determining the background

noise, the suit tester should stand still with his arms hanging along his sides

and he should hold his breath. The background noise level should be

recorded. Tests to measure the level of noise generated by the flow of air