Question

Q. 1 – Answer the following questions:  

According to [n=10, c=0], show what type of sampling? And illustrate what does it Mean?

Answer 1

Ans- It is important to establish a sampling plant that can effectively discriminate between good and bad lots. A lot in this case is defined as the quantity of goods that has been produced, handled, and stored within a limited period of time under uniform conditions.

There are 2 ways of sampling plans -

• 2-Class Attributes Sampling Plans
• 3-Class Attributes Sampling Plans

A 2-class attributes sampling plan specifies a maximum number of positive samples (s) out of a fixed number of samples (n). Samples may either be enumerated or the theoretical limit of detection (LOD) for a qualitative assay can be used to determine if a microbiological limit (m) has been exceeded.

A Three-class sampling plan is defined by (n,c,m,M) with an additional specification limit M> m; the lot is also rejected if at least one of the n measured log-concentrations is larger than M.

The given [n=10, c=0] is a A 2-class attributes sampling plan

Where

• n – number of sample units to be chosen number of sample units to be chosen independently and randomly from the lot independently and randomly from the lot
• c – maximum allowable number of sample maximum allowable number of sample units yielding a positive result units yielding a positive result (presence/absence testing) or exceeding the (presence/absence testing) or exceeding the microbiological limit m; for pathogens c is microbiological limit m; for pathogens c is usually set to 0

The 2-class attributes sampling plan simply classifies each sample unit as acceptable (nondefective) or unacceptable (defective). In some plans, the presence of any organism of a particular type would be unacceptable; in others, a limited number of organisms may be acceptable,  In the latter, a boundary is chosen, denoted by m, which divides an acceptable count from an unacceptable count. The 2-class plan rejects a lot if more than "c" out of the "n" sample units tested were unacceptable.

For 2-class n = 10, c = 0 requires that 10 sample units be tested and specifies a c value of 0. The lot would be rejected if any one of the 10 sample units tested was defective.