placed within the exposure zone that no drops
of solution from the test specimens or any
other source shall be collected. The collectors
shall be placed in the proximity of the test
specimens, one nearest to any nozzle and the
other farthest from all nozzles. The fog shall
be such that for each 80 cm2 of horizontal collecting
area there will be co llected in each collector
from 1.0 to 2.0 ml of solution per hour
based on an average run of at least 16 h (Note
10). The sodium chloride concentration of the
collected solution shall be 5 ± 1 weight percent
(Note II). The pH of the collected solution
shall be 6.5 to 7.2. The pH measurement
shall be made electrometrically or colorimetrically
using bromothymol blue as the indicator