Sampling is as important as testing. If the sampling is improperly done, the sample of the material will be in error, and the analysis will not represent the true properties of the material, and it may be impossible or impracticable to take another sample; whereas, if the sample is properly taken and the analysis is in error, another analysis can readily be made of the original sample.

Samples may be taken for either of the following two purposes:

4.2.1 To represent as nearly as possible an average of the bulk of the materials sampled, or

4.2.2 To ascertain the maximum variation in characteristics which the material possesses.

A good sampling plan has the following characteristics:

4.3.1 It protects the consumer against the acceptance of a bad batch of material.

4.3.2 It protects the producer against the rejection of a good batch of material.

4.3.3 It gives long-range protection to the consumer.

4.3.4 It encourages the producer to keep his process in control.

4.3.5 It minimizes the cost of sampling, inspection of testing, and administration.

4.3.6 It provides information concerning the quality of the product.

Sampling Integrity-When one takes a sample, one is attempting to represent a batch or lot of material with that sample. Different forms of pitch, and pitch in different types of containers, need to have different sampling plans and appropriate sampling equipment. Each sampling plan should be designed so that it accomplishes its objective, which is to ascertain the characteristics or quality of a batch or lot of material.