Return

Link to Checksheet

SUMMARY

SCOPE

Determine the moisture content in all papers, paperboard and fiberboard containers except those containing matter other than water that is volatile over 105 C.

APPARATUS

1. Weighting Container, air tight, for weighting specimen before and after drying. A glass bottle with a ground stopper is suitable for specimens of the order of 2.000 grams.
2. Thermometer to indicate the temperature of the drying oven. The thermometer shall include a temperature range from 100 C to 110 C.The thermometer should be divided by 1 deg. intervals.
3. Drying Oven, constant-temperature equipped with means for ensuring adequate temperature control and air circulation.
4. Chemical Balance sensitive to 1 mg. For weighting specimens of 2.000 g. and under and sensitive to 0.500 percent of the original weight of the specimen for the large specimens.
5. Desiccator, in which weighting containers and specimens are cooled after drying, Recommend that anhydrous aluminum (indicator grade) be used as the desiccant.

SAFETY

Following all lab safety rules

REFERENCE

ASTM D585

TEST SPECIMENS

1. When moisture is determined for the purpose of calculating moisture content the results test specimen should not weigh less than 2.000 g.
2. Calculating the amount of moisture from samples obtained in accordance with ASTM Method D585, D685.
3. When moisture is determined on combined board that are to be tested for other physical properties specimens should be cut from unsealed section and preferable from unprinted section

PROCEDURES

1. Determine tare weight before drying on the oven.
2. Transfer the test specimen to the drying oven at the temperature 105+/_ 3 C for 1 hour. at the of that period quickly close contained remove it from the oven, and place it in the desiccant to cool for 1 hour.
3. Transfer the test specimen to tare weighting as soon as specimens is cool. Record the specimen tare after drying in the oven.
4. Repeat the required drying and weighting operation until the difference in weight between two successive weights is not more than 0.100 percent of the weight of the specimen.
5. Make all weights to the nearest 1 mg for specimens of the order of 2.000 g and weight to within 0.500 percent on the weight original specimen for specimens over 2.000 g.

CALCULATION

When the percent of the moisture based on the original weight is required, calculate it as follows:

[ (W1-W2)/W1] x 100

Where:

W1 = original weight of specimen

W2 = weight of the specimen after oven drying

When the percentage of moisture based on the oven dry weight is required, calculate it as follow:

Moisture, percent = [ ( W1-W2 ) / W2] x 100

Where:

W1 = original weight of specimen

W2 = original weight of specimen after oven drying.

REPORT

Report the moisture as the percentage loss in weight of the specimen to the nearest 0.100 percent on the basis of the original weight.

Repeat CALCULATION steps.

REPEATABILITY

The results of the duplicate determinations of moisture should agree within 0.200 percent.