What is the AQL Sampling Inspection Criteria Table?

The AQL Sampling Test Criteria Table is the average quality level of the worst allowable process when a continuous series of batches is submitted for acceptance. AQL is widely used in the quality inspection of products in various industries, and different AQL standards are applied to the inspection 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.

Some principles that should be followed when determining an AQL:

1. The AQL value is a satisfactory process average quality, and it is expected that the average batch quality of the supplier will not exceed this value.

2. Consider the use of the product and the consequences caused by the failure of the product. For example, the AQL value of electronic components of the same specification can be larger when used in general civilian equipment than when used in military equipment; The AQL value can be larger when used for ordinary instruments than for precision instruments.

3. Although AQL is not a requirement for the quality of individual batches, if it is indeed known that the number of unqualified products per 100 units of a certain batch of products (or the number of unqualified products per 100 units) does not exceed the specified AQL value, the batch should be accepted; Otherwise, the batch should be rejected.

4. From the user's consideration, the AQL value cannot be required to be too small, otherwise, the inspection fee and product cost will increase, or the product batch is often rejected, so that the supplier refuses to sign the contract.

5. If the quality of the producer is difficult to improve the product urgently needed by the user, in order to get the product, the AQL value has to be selected to be appropriately larger, and the AQL value will be adjusted after the quality of the producer is improved.

6. When there are many spare parts, and the unqualified parts are easy to find and replaced with qualified parts when assembled as a whole, AQL can be selected larger; If a part cannot be removed from the whole part and replaced after failure, so that the whole part fails, AQL should be smaller.

7. From the perspective of assembly sequence, if the unqualified products of the previous process will cause a waste of time and material resources to the latter process, the AQL value of the previous process should be smaller than the AQL value of the latter process.

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).

<> 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. Before talking first, according to the number of batches and the test level, check the sample size word code, 20 according to the general test level II, and 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 the intersection of the two is found to contain Senqing, and the intersection point is "0 1" (shown in the blue circle), then the sample size of the sampling is the corresponding sample size of the bank "5" (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 spring suspicions and 1 rejection.

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.

For example, the number of samples for 2000 is 125, the AQL sampling scheme is (125, 7), and the AQL sampling scheme is (125, 10).

1 ) ac=acceptable number = use the first value below the arrow = use the first value above the arrow to sample the number of samples at the level II level of the general test.

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

Related Introductions

Sampling inspection, also known as sampling inspection, is a statistical method and theory that randomly selects a small number of products (sample answers) from a batch of products for inspection, and judges whether the batch of products is qualified for the reporting type. RUDN differs from a comprehensive inspection in that the latter needs to inspect the entire batch of products one by one and sort out the non-conforming products.

Sampling testing, on the other hand, infers the quality of an entire batch based on the results of the products in the sample. If it is inferred that the batch meets the pre-specified conformity criteria, it will be accepted; Otherwise, it will be rejected. Therefore, a batch of products that are considered qualified by sampling inspection may also contain some unqualified products.

The normal inspection of the one-time sampling scheme (AQL) is the abbreviation of --- acceptance quality limit, 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.

For the producer (or merchant), after considering the existing equipment, materials, technology, management and operation, it is considered that a certain degree of defective rate is acceptable to consumers (or buyers), and consumers (or buyers) can also accept such a defective rate (that is, the maximum defective rate of the limited good product group), which is called the allowable income level, which is expressed by AQL.

Bulk goods such as textiles are generally used or. The allowable level can also be used for brand clothing or ** higher or more demanding clothing.

He was a statistician, and we don't need to know how to calculate it.

It is not a uniform formula that can be calculated.

You need to look up a table to get a value that meets your requirements, just like you need to use a trigonometric table to look up trigonometric values.

Product 80, common inspection level 2, then spot check 13, AQL=1, 3 allowed.

Dizzy, isn't that playing the piano to the cow? There is no determination of AQL, sampling level, and the ghost knows how much to draw? Learn GB2828 on your own

20 pieces of 80 pieces are drawn, 1 piece is allowed for heavy defects, and 2 pieces are allowed for light defects.

AQL (Acceptable Quality Level) is the abbreviation of Acceptable Quality Level, which refers to the degree to which the product of the mold skin is unqualified under a certain quality standard. When conducting quality inspections, the number of samples needs to be determined according to the AQL.

The specific steps to determine the number of AQLs to sample are as follows:

Determine AQL and inspection level: Determine AQL and inspection level according to the quality requirements and usage scenarios of the products. In general, the AQL of general consumer goods is and the AQL of fine sail rolling instruments is.

Determine batch size: Determine the quantity of products to be inspected for quality, i.e., the batch size.

Find the corresponding AQL sampling plan: Find the sampling plan table that corresponds to the AQL and batch size. The ISO 2859 standard sampling schedule is usually used.

Determine the number of samples: Determine the number of samples according to the sampling schedule. The number of samples is related to batch size, AQL, and inspection level. In general, the number of samples increases with the size of the batch and increases with the decrease in AQL.

Conduct quality inspection: Conduct quality inspection according to the sampling quantity and sampling plan. According to the inspection results, judge whether the batch is qualified or not.

The AQL sampling number is determined based on the batch range, inspection level, and AQL value. In general, the smaller the AQL value, the larger the number of samples. The higher the level of inspection, the larger the number of samples. You can refer to the national standard "GB t Counting Sampling Test Procedure Zen Sakura Part 1:".

The determination of the AQL sampling quantity is based on factors such as the total number of samples, the quality grade, and the acceptable defective silver rate. Based on the total number of samples, the number of AQL samples is calculated.

The AC and RE in the AQL sampling standard represent the number of random inspections when the number of orders is sampled, and the number of orders is regarded as the number of random inspections, and the judgment array [AC, Re] of the sampling scheme remains unchanged

ac--accept(the number of qualified judgments);

re--reject (the number of failed decisions).

Extension: Acceptable Quality Limit is an abbreviation for acceptable quality limit, which is the average quality level of the worst process that can be allowed when a hail series batch is submitted for acceptance. AQL is widely used in the quality inspection of products in various industries, and different AQL standards are applied to the inspection of different substances.

In AQL sampling, the number of samples is the same, and the smaller the value followed by AQL, the smaller the number of defects allowed, indicating that the higher the quality requirements of the product source, the more strict the inspection. ac=0, re=1, it means that 0 defective products are allowed to be accepted, and 1 defective product is acceptable.