This standard specifies the sampling rules and acceptance criteria (referred to as sampling plan) for the application of statistical control methods in the sampling inspection of various performance items of high-voltage insulators (hereinafter referred to as insulators) with a rated voltage of 1000V and above. This standard only specifies the sample capacity of each performance test item when sampling and inspecting various types of insulators, but does not specify the total sample capacity, test grouping and test procedures for all items of sampling inspection. This standard applies to the inspection items of the size, appearance, mechanical, electrical and physical properties of insulators. JB/T 3384-1999 Sampling plan for high-voltage insulators JB/T3384-1999 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T3384
String Xiyuan
1999-08-06
Wa Xianji Dong
2000-01-01
JB/T3384
This standard is revised according to GB/T1.1-1993 Standardization Work Guide Unit 1: Drafting and Expression Rules of Standards Part 1: Basic Provisions for Standard Writing" to JB3384-83 High Voltage Insulator Sampling Plan. This revision has no change in technical content. From the date of implementation, this standard will replace JB334-83. Appendix A of this standard is the appendix of the standard. Appendix B of this standard is the appendix of the specification. This standard was proposed and managed by the National Insulator Standardization Technical Committee. The units that initiated this standard: Xi'an Electric Ceramics Research Institute and Suzhou Electric Ceramics Factory. The drafters of this standard: Liu Shuheng, Lu Jianmo, Li Dabu, this standard was issued in November 1983. 1. This standard specifies the sampling rules and acceptance criteria (referred to as sampling plan) for the application of statistical control methods in the sampling inspection of various performances of high-voltage insulators (hereinafter referred to as insulators) with a rated voltage of 1000V and above. This standard only specifies the sample quantity of each performance test item of various types of insulation during sampling inspection, but does not specify the total sample quantity, test grouping and test procedures for all items of the drag sample inspection. This standard applies to the inspection items of the size, appearance, mechanical, electrical and physical properties of insulators, including: a) Dimension inspection: b) Temperature cycle test c) Dimension inspection: h Electromechanical test: bZxz.net
d) Electromechanical destructive load test t
e) Mechanical destructive load test:
) Thermal machine (performance) test:
g) Power frequency breakdown voltage test
h) Porosity test:
i) Thermal shock test 1
) Hot dip galvanizing zinc layer test.
2 Definitions and special numbers
2.1 Definitions
This standard adopts the following definitions.
2.1.1 Unit product
The basic unit divided for the need to implement the same inspection is called a unit product. For example: a single product, a pair of products, a group of products, a component or a product of a certain length, a certain area, a certain volume, and a certain amount of product.
It may be consistent with or inconsistent with the unit product specified for procurement, supply, production or shipment. 7.1.2 Batch means "inspection batch", that is, a batch of unit products from which a sample is drawn for inspection to determine whether it meets the acceptance criteria. It can be different from the batch composed of products for other purposes (such as production, shipment, etc.). 2.1.3 Batch
The number of unit products contained in each batch, expressed as N. 2.1.4 Batch structure
The products are divided into identifiable batches, sub-batches, groups, or aggregated in other ways. The products in each batch should be of the same model, grade, type, size, structure, and production conditions and production time should be roughly the same. 2.1.5￥本
瓦极慢1999-08-06癌
2000-01-01小
JB/T33841999
Randomly draw a sample from each batch for One or more unit products for inspection. The number of unit products in the sample is called the sample capacity, expressed as n. Table 2.1.6 Average process defective rate
The average defective rate found during the initial inspection of the products provided by the supplier. Initial inspection refers to the first inspection of a certain number of products, which does not include the second sampling inspection during the secondary detailed inspection. 2.1.7 Acceptance quality level
In sampling inspection, the upper limit of the process average defective rate of the inspection batches submitted continuously that are considered acceptable. It is expressed as AQI. Batches with this quality level have a higher probability of acceptance. 2.1.8 Inspection plan
Determine the relationship between batch size and sample code, and determine the sample capacity according to the code and sampling plan type. 2.1.9 Acceptance probability
When inspected under a given sampling plan, the probability that a batch with a certain unqualified rate is judged to have passed. It is represented by P. 2.1.10 Sampling plan
The sampling plan stipulates the number of unit products (i.e. sample capacity) or sample capacity series drawn from each batch for inspection and the acceptance and rejection criteria (acceptance number and rejection number or acceptance quality band number) of the standard batch. 2.1.11 Piece sampling
Sampling inspection is a sampling inspection plan that simply divides the inspected performance into qualified or unqualified, and determines whether the batch has passed or not based solely on the number of unqualified products.
2.1.1 2 Quantitative sampling
In sampling inspection, the inspection sequence is based on the measurement results of product performance, and the judgment of whether the inspection batch passes or fails is determined by the sampling plan based on the function of the measurement value.
2.1.13 Single sampling plan
From a batch of products with a batch size (N), only a sample (n) is drawn and the inspection batch is judged to pass or fail based on the inspection results of this sample.
2.1.14 Secondary sampling plan
A two-stage sampling plan is a sampling method in which the sample is drawn twice, but whether the second sampling is carried out depends on the inspection results of the first sampling. When the second sampling is required, the batch is judged to pass or fail based on the inspection results of the first and second samples.
2.2 Symbols
2.2.1 N: batch.
2. 2. 2. 2 n; Sample size.
Note: nl is the first sample size, nt is the second sample size. 2.2.3A.: Acceptance judgment number.
2.2. 4R,; Rejection judgment number.
2.2.5d, Number of defectives contained in the sample. 2.2.P: Defective rate of the batch expressed as the number of defectives per hundred units of product. 2. 2. 7 AQL, Acceptance quality level. 2.2.8,: Probability of acceptance, that is, the percentage of batches expected to be judged as accepted. 2. 2. 9 K: Acceptance constant.
2.2.10Q: Quality index.
2.2.IL: Standard value of specified performance parameter. 2
3 Sampling rules
JB/T33841999
3.1 Types of sampling plans: This standard stipulates the use of two types of sampling plans: piece sampling plan (Chapter 4) and number-based sampling plan (Chapter 5). According to the acceptance quality level (AQL), ​​it is divided into four levels: 1.5%, 2.5%, 4.0% and 6.5%. 3.2 Sample capacity, code and inspection level The samples provided for sampling inspection shall be randomly thrown from the batch that has passed the factory (one) test. The sample capacity of the sample to be drawn is determined by the batch and the specified inspection level from Table 1, and the sample capacity determined by the code is specified in Table 2. Table 1 Sample capacity code
91-150
151500
501-12GG
12013200
3201--10000
10001--35000
2 Symbol description,
Table? Sample capacity code and sample capacity
The sample capacity of the first draw:
m-——The sample capacity of the second draw (if the single sampling plan is adopted, there is n): 2* Due to the particularity of the product, when the batch is small, the sample capacity is allowed to be "1". 4 Piece-count sampling plan
4.1 Piece-count sampling plan is divided into two types: single sampling plan and double sampling plan. 4.2 Criteria for piece-rate sampling schemes
4. 2. 1 Criteria for piece-rate and sub-sampling schemes are listed in Table 3. JB/T33841999
Table 3 Criteria for piece-rate single sampling schemes
Sample capacity
Acceptance determination number!
From this column, go down to the first cell with an acceptance (A) and a rejection number (R), and then use this group of numbers and the sample capacity (n,) corresponding to this cell. From this column, go up to the first cell with an acceptance and a rejection number, and then use this group of numbers and the sample capacity corresponding to this cell to reject the determination number#
Criteria for piece-rate two-drink sampling schemes are listed in Table 4. 4. 2. 2
Table 4 Criteria for piece-rate two-sampling schemes
This capacity
Acceptance determination number. The acceptance determination number for the first sampling is A.The acceptance judgment number for the second sampling is A1, and the corresponding ---sampling plan (print the sample size code and AQL corresponding to this cell) should be used, or the rejection judgment number of the secondary sampling plan in the next cell of this column should be used. The rejection judgment number for the first sampling is RI and the rejection judgment number for the second sampling is R..R.
(and the capacity code and AQL)
From this column, lead down to the appropriate grid. Then use the sampling plan according to the instructions *. 4.3 Piece-rate sampling plan judgment procedure
4.3.1 Piece-rate primary sampling plan judgment procedure JB/T3384
Randomly select II samples from N and conduct tests on them. Among them, the number of unqualified products is l
, and accept this batch
4.3.2 Piece-rate secondary sampling plan judgment procedure Randomly select n samples from N and conduct tests on them. Among them, the number of unqualified products is d
If d, Ael
If Ad, R
Reject this batch
If d, R
, then select n from the batch. The sample is subjected to a second test, and the number of defective products is d
If d,+d,≤A
Accept this batch
Ten-dimensional sampling plan
If d,+d,R.
Reject this batch
5.1 The measurement sampling plan specified in this standard is designed based on the principle of percentage defect measurement inspection using the unknown standard deviation method based on the distribution law of sample measurement values ​​obeying the normal distribution law. Note: In some cases, such as when the insulator is subjected to a factory test load exceeding 8% of the specified damage load, or when there is a double peak branch, this method is generally not applicable. 5.2 Criteria for determination of the measurement sampling plan
5.2.1 The acceptance constant K value of the measurement-second sampling plan is listed in Table 5. Sample capacity
JB/T33841999
Table 5 The acceptance constant K value of the measurement sub-sampling plan AQL
When there is no suitable inspection level, the first acceptance constant and the spring capacity below the arrow are used. Note:
5.2.2 The acceptance constant K value of the measurement sub-sampling plan is listed in Table 6. Table 6 The acceptance constant K value of the measurement sub-sampling plan Sample capacity
Acceptance band number
The acceptance constant of the first sampling
K—The rejection constant of the first sampling 1
K,—The acceptance constant of the second oil sample.
5.3 Measurement sampling plan determination procedure
Acceptance quality level
5.3.1 Measurement primary sampling plan determination procedure JB/T33841999
Randomly select II samples from the batch N for testing and calculate the test result Q.
If Q,≥K
Accept this batch
5.3.2 Measurement secondary sampling plan determination procedure If QK,
If K,≥Q2K
Draw II.sample from the batch
Conduct a second test
Calculate the test result Q:
If Q,>K
Accept this batch
5.4 Calculation procedure for counting sampling plan
If Q
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