A Study of Appropriate Duration for Removing Moisture from PVC Filter Paper before Dust Sampling

Abstract

Objectives: the objectives of this research were: 1) to compare PVC filter paper weights after  removing  moisture by an auto-desiccator at  relative humidity of 25, 40, and 60% within  duration of 2, 4, 6, 8, and 24 hours; 2) to study the difference of PVC filter paper weights after removing moisture in the auto-desiccator at difference relative humidity and duration; and; 3) to find  relations  of moisture removal  from  PVC filter paper by the auto-desiccator at  difference relative humidity and duration.

Research Method: Each PVC filter paper was weighted before and after removing moisture by the auto-desiccator at relative humidity of 25, 40, and 60% within duration of 2, 4, 6, 8, and 24 hrs. Each weighing with changing new PVC filter paper was repeated for 5 times.

Research Results: At 25% relative humidity, difference means of the PVC filter paper weights after moisture removing at 2, 4, 6, and 8 hours were not significantly different with 24 hours. Meanwhile, the difference mean  of the PVC filter paper weights  at the 40%  relative humidity and at 2 hours was significantly different with  24 hours but not significantly different with 4, 6, and 8 hours. Moreover, at 60% relative humidity, the difference means of the PVC filter paper weights at 2, 4, 6, and 8 hours were significantly different with 24 hours.

Recommendation: Moisture removing duration from PVC filter paper should be compared after dust sampling as well as relative humidity should be controlled at the same level between the experimental room and the auto desiccator.