Printed matter AQL sampling standard books

According to the "CY T 12-1995 Rules for the Inspection and Sampling of Printed Books".

Batch quality qualified provisions.

In the order contract, the ordering party and the supplier shall negotiate to determine the conditions for the quality of the batch. If there is no clear provision on this, it will be implemented according to the number of unqualified products per 100 units of products. See Appendix A.

Appendix A Judgment of Qualified Product Batch Quality (Supplement).

Sampling test is a scientific test method based on probability theory and mathematical statistics. It is an inspection method that takes samples from batch products and uses the sample test results to determine whether the quality of the entire batch of products is qualified.

Since it is impossible to absolutely guarantee that there are no nonconforming products in the products submitted for inspection, when judging whether the batch quality of the product is qualified, it is first necessary to determine the standard value of the nonconforming product rate. For a single inspection batch, the number of unqualified products per 100 units of product shall be specified; For a series of successive inspection batches, the maximum number of non-conforming products per 100 units of product acceptable to the supplier is specified. This value is referred to as the acceptable quality level in the sampling inspection and is expressed as AQL.

The smaller the standard value of the non-conforming product rate, the smaller the number of qualified judgments for the same sample, and the more difficult it is to pass the inspection batch.

This standard stipulates that for a single inspection batch or a continuous inspection batch, the standard value of the non-conforming product rate is 4, that is, the maximum number of non-conforming products per 100 units of product or the qualified quality level (AQL) is.

AQL sampling steps:

Looking at the inspection criteria, a complete inspection item should contain 3 elements: batch number, inspection level, and AQL value.

For example, if the batch number of a certain inspection item is 20, according to the general inspection level II, the AQL value is pressed respectively.

1. First of all, according to the number of batches and the test level, check the sample size word code, 20 according to the general test level II, the corresponding sample size word code is C.

3. Then how to select the sampling scheme when looking at the AQL value.

Look at the sampling scheme table and find the sample size code "C" on the left, and the Received Quality Limit (AQL) 2" above, as shown in the red circle. If you find the intersection of the two, and the intersection point is "0 1" (shown in the blue circle), then the sample size of the sample is the corresponding sample size "5" in this row (shown in the blue circle in the header).

Therefore, the batch of 20 pieces, according to the general inspection level II, AQL value, the sampling scheme is: 5 samples, 0 receive and 1 reject.

4. Let's look at the sampling scheme at AQL value.

Similarly, find the "c" on the left and the top ", find the intersection of the two, and find that the intersection is a downward arrow!

It's different here, please see ** The following remarks: The down arrow indicates "use the first sampling scheme below the arrow". Follow the arrow to find the first number "0 1" (circled in blue) and move on to the next step.

5. Look at the number "0 1" to the left and find the sample size "13" (blue circle), which is the sampling number of this sampling scheme.

Therefore, when the batch of 20 pieces, according to the general inspection level II and AQL value, the sampling scheme is: 13 samples, 0 receive and 1 reject.

6. Finally, let's look at the sampling scheme when the AQL value is timely.

See **Note below: If the sample size is equal to or exceeds the batch, then perform a 100% test.

Therefore, in batches of 20, according to the general inspection level II, when the AQL value is used, the sampling scheme is: 20 are fully inspected, 0 receive and 1 reject.

After the sample size code obtained from the 105e table, read the sample size n in the sample size column from the row where the character code is located to the right in the sampling scheme table, and then read out the received number ac and the rejection effect re at the intersection of the row where the sample size code is located and the column where the specified receiving quality limit is located, and if it is an arrow at the intersection, it will be along the side.

The arrow direction reads out the first received number ac and the rejected number re, and then the row where the received number and the rejected number are located to the left, and reads the phase in the sample size column.

The sample size should be n.

Refer to GB T2828-2003

The table is as follows:

AQL Sampling Method:

1. Simple random sampling method (each individual has the same chance, similar to the familiar drawing lot).

2. Systematic random sampling method (equidistant or mechanical).

3. Stratified sampling method (simple random sampling according to the characteristics of the product, such as: safe, severe, and extremely serious sampling).

4. Group sampling method (grouping).

Inspection standards.

AQL: is an abbreviation for acceptable quality limit.

Spot check checklist (GB2828-87).

Number of products Number of samples ac re Number of samples ac re

Note: ac - accept (the number of qualified judgments); RE - RCJECT (number of unqualified judgments) example: the number of orders is 3000 pieces, 125 pieces are randomly checked according to the standard, the number of defective products is 7 on pass (passed), the number of defective products is 8 on failure (unqualified) The number of orders is 7 pieces, 5 pieces are spot-checked according to the standard, no defective products are passed, and one defective product is fail; If it is in accordance with the standard, only 3 pieces will be randomly checked, and no defective products will be passed.

There are 5 ** left, let's see!

Relaxation is still 32 units, tightened, normal, relaxation and sampling are okay, AC RE depends on your AQL = which. It doesn't matter what your AQL is equal to, the sample is 32

There is a ** in the national standard document, which is very clear. Give me an email and I'll send it to you.

aql :

Acceptable Quality Limit is an abbreviation for acceptable quality limit, which is the average level of quality of the worst process that can be allowed when a continuous series of batches is submitted for acceptance.

AQL is widely used in export garment, textile inspection, AQL standards are,,,AQL10, AQL15, AQL25, AQL40, AQL65, AQL100, AQL150, AQL250, AQL400, AQL650, AQL1000. Different AQL standards are applied to the testing of different substances. In AQL sampling, the same number is extracted, and the smaller the value followed by AQL, the lower the number of defects allowed, indicating that the higher the quality requirements and the stricter the inspection.

Here's a list of the different AQLs:

During the inspection, the number of samples and the number of qualified and unqualified products are determined according to the batch range, inspection level, and AQL value. The garment quality inspection adopts a sampling scheme, the qualified quality level (AQL) of the garment batch is, the inspection level is the general inspection level, and the strictness of the inspection is the normal inspection.

The sampling scheme is shown in the table

Normally check the one-time sampling scheme (AQL is the abbreviation of --- accept quality level, which is an international standard, 1) ac=acceptable number = use the first value below the arrow = use the first value above the arrow.

The number of samples is carried out at the level of general inspection level II.

2) It is used for inspection of electronic products, medical equipment, etc.

It is used for garment, textile inspection, etc.

It refers to a sampling parameter, which is generally used for mass production, and the inspector samples are sampled and inspected to pass or not.

Note: When the number of orders is the number of random checks, the order quantity is regarded as the number of random checks, and the judgment array [ac,re] of the sampling scheme remains unchanged

ac - accept (the number of qualified judgments);

re——rcject (number of failed judgments).

Example 1: The number of orders for a batch of clothing is 3,000 pieces, and 125 pieces are randomly inspected according to the standard, and the number of defective products is 7 on the pass (pass), and the number of defective products is 8 on the fail (unqualified).

Example 2: The number of orders is 7 pieces, 5 pieces are randomly checked according to the standard, no defective products are passed, and one defective product is fail; If it is in accordance with the standard, only 3 pieces will be randomly checked, and no defective products will be passed.

Spot check checklist (GB2828-87).

Number of orders The number of pieces to be inspected.

ac re ac re

The smaller the value of the AQL heel, the lower the allowable number of defects, indicating that the higher the quality requirements, the more stringent the inspection.