Portugal Inspection, Quality Control Assurance Services, Factory Audit - Product Testing and Certification in Portugal

At Portugal Quality Control we perform quality control services in Portugal according to the international standard ANSI ASQC Z1.4 - ISO 2859 - MIL STD 105E. Our inspectors inspect your productions directly on site according to an established protocol by our supervisors and according to our clients requirement.

In order to establish how many pieces/products will be inpected by our employees, we use the Acceptable Quality Limit tables provided below. AQL is a method allowing to estimate if a production batch should be accepted or rejected by considering a sampling operated on a random selected part of this production.

In order to learn how this method determines how many pieces are selected, let's work on an example:

Considering a production of 10 000 units.
1/ First you have to know that an unit is the smallest element you consider on a production.
2/ In order to know how many units will be selected you have to choose a general inspection level.

A general inspection level involves the accuracy used to led the inspection of your product.
Most of the importers use General Inspection Level II to inspect a batch of product and Special Inspection Levels are reserved for special test led on products (such as torn test, high pot test, strength test, etc...).

So now, let's consider 10 000 units ordered by an importers who chosse General Inspection levels II. In the table 1 you get L as sampling size code letters.

Now by reporting this letter in the table 2, you get 200, which is how many pieces have to be inspected over 10 000 to represent statistically the quality of the batch of 10 000 piecs.

TABLE 1

TABLE 2