SJ 20275-1993 General specification for positive temperature coefficient thermistors

SJ 20275-1993 General Specification for Positive Temperature Coefficient Thermistors SJ20275-1993 Standard download decompression password: www.bzxz.net

Military Standard of the Electronic Industry of the People's Republic of China FL5911
SJ20275—93
General specification for positive temperature coefficient thermistors
General specification for positive temperature coefficient thermistors1993-
Published by China Electronics Industry Corporation
1993-Implementation
1.1 Subject content
1.2 Applicable scope
1.3 Classification．
Model specification
Nominal zero-power resistance and allowable deviation
Reference documents
Detailed requirements,
Qualification appraisal
Design and structure
Resistor
Lead terminals
Weldability
Power resistance value
Resistance ratio
Short-term load
Insulation resistance
Dielectric withstand voltage:||tt ||Low temperature storage
High temperature storage
Thermal time constant
Dissipation factor (when applicable)
Terminal strength
Resistance temperature characteristics
Temperature shock
Resistance to soldering heat
Load life
Long-term high temperature exposure
High frequency vibration
Water immersion·
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3.24Water immersion·
3.25 Add T. Quality
4 Quality Assurance Provisions
4.1 Inspection Responsibility
4.2 Inspection Classification
Inspection Conditions and Precautions
Identification Inspection
Quality Consistency Inspection
Inspection Methods
5 Delivery Preparation
Order Contents
Introduction, Definition and Description
Resistance Ratio
Result Point Temperature tt||Switching point temperature, tt||Equilibrium point swirl ·
Maximum operating temperature
6.3 Flammability
Appendix A
Identification and inspection procedures
A1 Scope
Test data
Product description
Identification and inspection
People's Republic of China Electronic Industry Military Standard General specification for positive temperature coefficient thermistors
General specification for positive temperature coefficient thcmistors1 Scope
1.1 Subject content
SJ20275—93
This standard specifies the general requirements for insulated positive temperature coefficient thermistors (hereinafter referred to as thermistors). 1.2 Scope of application
This specification applies to insulated positive temperature coefficient thermistors used for temperature compensation, temperature control and delayed current limiting within a certain temperature range.
1.3 Classification
1.3.1 Model Specifications
The model specifications of thermistors in this specification shall conform to the following example: Mzll
1.3.2 Model Composition
Nominal Zero Power Resistance Value
Allowable Deviation of Zero Power Resistance Value
The model is represented by two letters "MZ" followed by two numbers: the letter "Z" represents a military insulating positive temperature coefficient thermistor, the first digit represents the main purpose, and the second digit represents the sequence number. 1.3.3 Characteristics of thermistors
The characteristics of thermistors are represented by resistance ratios, and their values ​​are specified in the detailed specifications. The resistance ratio deviation is represented by a letter (see Table 1). The numbers before the letters represent the integer value of the resistance ratio, and the numbers after the letters represent the decimal value of the resistance ratio. For example, when the resistance ratio is 20.5±10%, it is represented as '20A5. Resistance ratio deviation
Allowable deviation (%)
1.3.4 Nominal zero-power resistance value and allowable deviation ±20
The nominal zero-power resistance value is calibrated at 25°C, in ohms, and expressed mathematically. The resistance range applicable to this specification is 10~100k2, and its resistance series conforms to GB247i. China Electronics Industry Corporation 1993-－Published
1993-Implementation
ITKAONKAca-
SJ 20275—93
The allowable deviation of the nominal zero-power resistance is measured at 25°C 0.1“℃ and is represented by a letter code. For details, see Table 2. Allowable deviation code of nominal zero-power resistance
Referenced documents
GB 2471
GB 4475
Packaging, purchase and transportation instructions
Nominal zero-power resistance range
10~1000
Resistance value <100
Resistance value >1000
Resistors for electronic equipment Nominal resistance series Sensitive components Terminology
GJB 360.4
GJB 360.5
GJB 360.6
GJB 360.8
GJB 360.15
GJB 360.18
GJB360.20
GJB 360.21
GJB 360.23
G1 360.27
GJB 360.28
3 Requirements
3.1 Detailed specifications
Test methods for military electronic components
Immersion test
Test methods for military electronic components
Low pressure test
Test methods for military electronic components
Test methods for military electronic components
Test methods for military electronic components
Test methods for military electronic components
Test methods for military electronic components
Test methods for military electronic components
Test methods for military electronic components
Test methods for military electronic components
Test methods for military electronic components
Test methods for military electronic components
Test methods for military electronic components
Military electronic components test
Temperature shock test
High temperature life test
High frequency vibration test
Solderability test| |tt||Welding heat resistance test
Terminal strength test
Impact test
Dielectric withstand voltage test
Insulation resistance test
Allowance deviation of zero-power resistance value
The requirements for thermistors shall comply with the provisions of this specification and relevant detailed specifications. If there is a conflict between the requirements of this specification and the detailed specifications, the detailed specifications shall prevail. 3.2 Qualification appraisal
Thermistors submitted in accordance with this specification: should be products that have been appraised as qualified. 3.3 Design and structure
The design, structure and external dimensions of thermistors shall comply with the provisions of the detailed specifications. Each thermistor shall have a resistance value sintered at high temperature and be protected by a moisture-proof and insulating casing or coating material to prevent the resistor body from being directly exposed to environmental conditions. -2-
3.3.1 Resistor body
SJ 20275—93
The resistor body shall be flat and free of mechanical defects such as cracks and pores, and its external dimensions shall comply with the provisions of the detailed specifications. 3.3.2 Lead Terminals
In order to facilitate welding, the surface of all lead terminals shall have a good coating. The size of the lead terminals and their lead-out methods shall comply with the regulations (see 3.1). 3.3.3 Flux
When flux is required in the manufacturing process, non-corrosive flux should be selected unless it is confirmed that the flux has become neutral after welding.
3.3.4 Mass
The total mass of the thermistor shall not exceed the specified maximum value (see 3.1). 3.4 Solderability
When thermistor resistors are inspected in accordance with 4.6.5 of this specification, the impregnated surface of the lead terminals shall be covered with at least 95% of the new solder, and the remaining 5% of the surface is only allowed to have small and unconcentrated pinholes or pores. Poorly impregnated surfaces will result in deteriorated solderability or cause failure. If there is a dispute over the impregnated surface, it should be determined through actual measurement. 3.5 Zero-power resistance value
When thermistor is tested in accordance with Article 4.6.3 of this specification, its zero-power resistance value and allowable deviation shall comply with Table 2 and the detailed specifications.
3.6 Resistance ratio
When thermistor is tested in accordance with Article 4.6.4 of this specification, its resistance ratio and allowable deviation shall comply with Table 1 and the detailed specifications.
3.7 Short-term load
When thermistor is tested in accordance with Article 4.6.6. When tested according to this specification, there should be no arcing, burning, scorching or open circuit. The change in the 25°C power resistance value after the test shall comply with the provisions of the detailed specifications. 3.8 Insulation resistance
When thermistors are tested according to Article 4.6.7 of this specification: the insulation resistance shall not be less than T500M2. 3.9 Dielectric withstand voltage
When thermistors are tested according to Article 4.6.8 of this specification: there should be no signs of mechanical damage, arcing or penetration. 3.10 Low temperature storage
When thermistors are tested according to Article 4.6.9 of this specification, there should be no mechanical damage, and the change in resistance value after the test shall comply with the provisions of the detailed specifications.
3.11 High temperature storage
When thermistors are tested according to Article 4.6.10 of this specification, there should be no mechanical damage, and the change in resistance value after the test shall comply with the provisions of the detailed specifications.
3.12 Thermal time constant
When thermistor is tested according to 4.6.11 of this specification, the thermal time constant shall comply with the detailed specification. 3.13 Dissipation factor (when applicable)
A is being considered.
3.14 Terminal strength
When thermistor is tested according to 4.6.13 of this specification, it shall be able to withstand the specified tensile force without mechanical damage. After the test, the change in the 25°℃C zero-power resistance value shall comply with the detailed specification. 3.15 Resistance temperature characteristics
When thermistor is tested according to 4.6.14 of this specification, the measured data shall comply with the detailed specification. 3.16 Temperature shock
Thermistors shall have no mechanical damage when tested in accordance with Article 4.6.15 of this specification. The change in 25°C zero-power resistance value after the test shall comply with the provisions of the detailed specification.
3.17 Welding heat resistance
Thermistors shall have no mechanical damage when tested in accordance with Article 4.6.16 of this specification. The change in 2S°℃ zero-power resistance value after the test shall comply with the provisions of the detailed specification.
3.18 Moisture resistance
Thermistors shall show no signs of mechanical damage, open circuit or loose lead terminals when tested in accordance with Article 4.6.17 of this specification. The change in zero-power resistance at 25°C after the test shall not exceed ±10%; the insulation resistance shall be no less than 100M2. 3.19 Load life
Thermistors shall show no corrosion or other mechanical damage when tested in accordance with Article 4.6.18 of this specification; the change in zero-power resistance shall comply with the provisions of the detailed specifications:
3.20 Long-term high temperature exposure
Thermistors shall show no mechanical damage when tested in accordance with Article 4.6,19 of this specification: the change in zero-power resistance at 25°C after 100h and 1000h tests shall comply with the provisions of the detailed specifications. 3.21 High-frequency vibration
Thermistors shall show no mechanical damage when tested in accordance with Article 4.6.20 of this specification; the change in zero-power resistance at 25°C after the test shall comply with the provisions of the detailed specifications.
3.22 Impact
Thermistors shall be free from mechanical damage when tested in accordance with Article 4.6.21 of this specification: the change in the 25°C zero-power resistance value after the test shall comply with the provisions of the detailed specifications.
3.23 Water immersion
Thermistors shall be free from corrosion or other mechanical damage when tested in accordance with Article 4.6.22 of this specification: the change in the 25°C zero-power resistance value after the test shall comply with the provisions of the detailed specifications. 3.24 Marking
Thermistors shall be marked with the model, characteristic code, nominal zero-drum resistance value and allowable deviation, manufacturer's name or trademark, and production batch number. If the area required for marking is insufficient, it can be marked on the packaging. 3.25 Processing quality
The manufacturer shall adopt a method that can ensure the quality consistency and repeatability requirements. The product shall be free of cracks, fragmentation, and other defects that affect life and reliability. 4 Quality Assurance Provisions
4.1 Inspection Responsibility
Unless otherwise specified in the contract or order, the contractor shall be responsible for completing all inspections specified in this specification. If necessary, the ordering party or the superior appraisal agency has the right to inspect any inspection item described in the specification. 4.1.1 Test Equipment and Inspection Facilities
s± 20275--93
The test equipment and inspection facilities shall have sufficient accuracy, quality and quantity to carry out the required inspections. 4.2 Inspection Classification
The inspection classification specified in this specification is as follows: a: Appraisal inspection (see Article 4.4):
b. Quality consistency inspection (see Article 4.5). 4.3 Inspection Conditions and Precautions
4.3.1 Inspection Conditions
Unless otherwise specified, all inspections in this specification shall comply with the test conditions specified in the "General Requirements" in GJB360.1.
4.3.2 Precautions
Precautions that meet the requirements shall be taken to prevent moisture from condensing on the thermistor during inspection, except when moisture is a requirement for the test. Precautions shall also be taken when thermistors need to be welded to prevent accidental damage caused by local overheating during welding.
4.4 Qualification Inspection
Qualification inspection shall be carried out in a laboratory approved by the competent authority (see Article 6.2). 4.4.1 The number of samples submitted for inspection shall be as specified in Appendix A of this specification. These samples shall be drawn from production lines using normal equipment and manufacturing technology.
4.4.2 The samples submitted for inspection shall be subjected to qualification inspection in accordance with the items and sequence specified in Table 3 of this specification. Except for the samples in Group 1a, the remaining samples shall be inspected by Group 1. Then, samples are taken from Group 1 and subjected to their respective inspections as specified in Table 3. 4.4.3 Number of nonconforming items
When the number of nonconforming items exceeds the number allowed by this specification, it shall constitute the basis for identification of nonconformity. Table 3
Inspection or test
Group I
Appearance and mechanical inspection1)2)
Nominal resistance
Resistance ratio
Group Ia
Solderability}
(If applicable)
Group II
Short-term load
Insulation resistance
Withstand voltage
Low-temperature storage
Commercial temperature storage
Terminal strength
Requirement clause
Method clause
Number of samples (pieces)
Total samples
20 single lead or
10 pairs of leads
Allowable nonconformity
Number of qualified products (pcs)
Total nonconformity
Number of qualified products
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Inspection or test
Group 3
Resistance temperature
Temperature shock
Welding heat
Group 4
Load resistance
Group 5
Long-term high temperature
Group 6
Number of hot time bands
Dissipation coefficient
High frequency vibration
Requirement clause
SJ 20275—93
Continued Table 3
Method Clauses
Number of Samples (pieces)
Number of Nonconforming
Qualified Products Allowed (pieces)
Total Number of Nonconforming
Qualified Products
Note: 1) If the same sample fails in only one or more tests in one of the tests, only one nonconforming product number will be treated. 2) Only when the marking is incorrect, incomplete or unclear, it is judged as a nonconforming product. 3) Samples in Group 1a are not subject to Group 1 test. 4.4.4 Maintenance of Qualification
To maintain the qualification, the manufacturer shall submit a report to the qualification body every six months. The qualification body shall specify the date of the first report. The report content is as follows;
a. Summary of the results of product delivery inspection (Group A and Group B inspection), which should at least indicate the number of qualified batches and the number of unqualified batches, and should indicate the test results of all rework batches; b. Summary of the results of periodic inspection (Group C inspection), including the number of unqualified products and failure modes. The summary should include all periodic inspection results completed within the six-month cycle. If the summary shows that the specification requirements are not met and the corrective measures agreed by the appraisal body are not taken, the corresponding products may be withdrawn from the qualified product list. If the report is submitted within 30 days after the six-month cycle, the product appraisal qualification may be lost. In addition to regular submission of inspections, when the inspection data at any time within the six-month cycle shows that the identified product does not meet the requirements of this specification, the manufacturer shall immediately notify the appraisal body.
If there is no production within the period of submitting the report, a report shall be submitted to prove that it still has the necessary capacity and facilities to produce the product. If there is no production within two consecutive reporting cycles, the appraisal body may decide to require the manufacturer to state the reason for non-production and submit the identified products for testing according to the appraisal inspection requirements. 4.5 Quality consistency inspection
4.5.1 Chair inspection
SJ 20275--93
Inspection consists of Group A inspection and Group B inspection. 4.5.1.1 Inspection batch
The inspection batch shall consist of thermal resistors of the same model, resistance ratio and production batch number. 4.5.1.2 Group A inspection
Group A inspection shall consist of the inspection or test specified in Table 4. 4.5.1.2.1 Sampling plan
Counting inspection and sampling shall be in accordance with the general inspection level I in GJB179, and the acceptable quality level (AOL) and limit quality (LQ) shall comply with the provisions of Table 4.
Major defects and minor defects shall comply with the provisions of GJB179. Table 4 Group A Inspection
Inspection or Test
Appearance and Mechanical Inspection
Electrode Body Size
Leader Terminal Size
Processing Quality
Zero Power Resistance Value
Electrode Attachment Ratio
Requirement Clause
Method Clause
Major Defect
1.0 (AQL)
Minor Defect
18.0 (LQ)
Jiang: 1) Marking defective products refer to unclear, incorrect or incomplete markings. Any subsequent performance defects cannot be regarded as marking defective products.
4.5.1.2.2 Batch acceptance
If the test product is rejected, the manufacturer can take back the batch of products for return "corrective measures or eliminate non-conforming products, and then resubmit for inspection. The batch resubmitted for inspection should be separated from the new batch and clearly marked as a re-inspection batch. 4. 5. 1. 3 Group B inspection
Group B inspection should be carried out according to the tests and sequence specified in Table 5. Unless the quality supervision department proposes to draw a separate sample for Group B inspection, it should generally be drawn from the inspection batch that has passed the Group A inspection. Table 5 Group B Inspection
Test Items
Short-term Load
Insulation Resistance
Dielectric Withstand Voltage
Low-temperature Storage
High-temperature Storage
4.5.1.3.1 Sampling Order
Requirement Clause
Method Clause
Unless otherwise specified, the sampling procedures of this specification shall comply with the general inspection level I specified in GJB179: AQL and LQ are 4.0 and 18.0% respectively.
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4. 5. 1. 3.2 Rejection of Batch
SJ 20275—93
If the test product is rejected, the manufacturer may rework the batch to correct the defects or remove the nonconforming products and then resubmit for inspection. The batches to be resubmitted for inspection shall be separated from the new batches and clearly marked as re-inspected batches. 4.5.1.3.3 Sample handling
Unless otherwise agreed between the supplier and the buyer, samples that have passed the Group B inspection shall not be delivered according to the contract. 4.5.1.4 Periodic inspection
Periodic inspection shall be composed of Group C inspection, and its items and sequence shall be specified in Table 6. Group C inspection samples shall be drawn from the inspection batches that have passed the Group A and Group B inspections.
4.5.1.4.1 Sampling
4.5.1.4.1.1 Monthly inspection
Monthly inspection includes two groups, C1a and C1b. Group C1a consists of 10 samples of any resistance value, and one unqualified sample is allowed during inspection. Group C1b consists of 10 samples (when double-lead terminals are inspected) or 20 samples (when single-lead terminals are inspected), and one unqualified sample is allowed each time. If there are more than 1 defective product in any group, re-inspection shall be carried out with double the number, and no defective products are allowed. 4.5.1.4.1.2 Quarterly inspection
Ten samples are selected from each of the three groups for quarterly inspection. The nominal zero-power resistance value of these samples should be between the minimum value and the middle value, and samples with smaller resistance values ​​are selected for C2b group test. During the test, one defective product is allowed in each group, but the total number of defective products in each group shall not exceed 1. 4.5.1.4.1.3 Half-year inspection
Ten samples with the highest resistance values ​​are allowed to have only one defective product during the half-year test. Table 6 C Group inspection
Test items
C1 group
C2 group
Cla group
End strength
Clb group
Weldability
C2a group
Resistance temperature characteristics
Temperature shock
Resistance to welding heat
C2h group
Load life
C2c Grouping
Long-term commercial temperature exposure
Number of samples for test
20 single leads or
10 double leads
Requirement clause
Elimination clause
Test item
C3 Grouping
Time constant
Dissipation coefficient
High-frequency vibration
4.5.1.4.2 Sample treatment
SJ 20275—93
Continued Table 6
Number of samples for test
Samples that have undergone Group C testing shall not be delivered according to the contract or order. 4.5.1.4.3 Failure
Request Clause
Method Clause
If the C group test fails, the manufacturer must take corrective measures for products with basically the same materials and processes, and products that are considered to have the same failure mechanism. At this time, the product should stop acceptance until the corrective measures taken are recognized by the competent department. After the corrective measures are taken, the products should be re-sampled for C group test (all items or only unqualified items, determined by the quality supervision department). Group A and Group B can also be re-tested. However, only when the results of the C group test re-test prove that the corrective measures are successful can the final acceptance be carried out. If it is still unqualified after re-testing, the relevant failure analysis and corrective measures should be provided to the appraisal agency. 4.5.1.4.4 Special treatment of C group inspection
When the product cannot be submitted for inspection on a monthly, quarterly or semi-annual basis, the same inspection can be used for appraisal inspection (see 4.4) after obtaining the opinion of the quality supervision department or the quality supervision department. Carry out according to the submitted batch. 4.5.2 Packaging Inspection
The inspection of packaging shall comply with the provisions of Chapter 5 of this specification. 4.6 Inspection Methods
4.6.1 Appearance and Mechanical Inspection (see 3.1, 3.3, 3.24 and 3.25) Appearance and mechanical inspection shall be carried out using instruments and methods with sufficient accuracy to verify that the design, structure, materials, dimensions, marking and processing quality meet the requirements of this specification. 4.6.2 Zero Power Resistance
4.6.2.1 Measurement Temperature and Accuracy All thermistors shall be measured in a homogeneous medium with a specified temperature and an accuracy of ±0.1°C (see 3.1).
4.6.2.2 Errors in the measurement methods:
a. Direct method for measuring the resistance value: should not exceed 10% of the allowable deviation of the zero-power resistance value: b. Indirect method for measuring the resistance value: should not exceed 10% of the maximum change in the zero-power resistance value: When using methods a and b to measure thermal resistors, the time response characteristics of the measuring device should be consistent with the test sample in accordance with the provisions of Article 4.6.2.1:
c. Instrument sensitivity The sensitivity of the instrument used should meet the test requirements. The time response characteristics of the test conditions should be consistent with the test sample.
4.6.2.3 The test procedure shall be carried out in accordance with the following provisions a. Installation Clamp the thermal resistor to a yellow rod with a diameter of 3mm in the prescribed manner. The distance from the clamping position to the end of the resistor body is 25.4±1.5mm; -9-
HTKAONTKAca-2 Acceptance of batches bZxz.net
If the test product is rejected, the manufacturer may take back the batch of products for return "corrective measures or eliminate non-conforming products, and then resubmit for inspection. The batch resubmitted for inspection should be separated from the new batch and clearly marked as a re-inspection batch. 4. 5. 1. 3 Group B inspection
Group B inspection should be carried out according to the tests and sequence specified in Table 5. Unless the quality supervision department proposes to draw a separate sample for Group B inspection, it should generally be drawn from the inspection batch that has passed the Group A inspection. Table 5 Group B Inspection
Test Items
Short-term Load
Insulation Resistance
Dielectric Withstand Voltage
Low-temperature Storage
High-temperature Storage
4.5.1.3.1 Sampling Order
Requirement Clause
Method Clause
Unless otherwise specified, the sampling procedures of this specification shall comply with the general inspection level I specified in GJB179: AQL and LQ are 4.0 and 18.0% respectively.
TYKAOKAca-
4. 5. 1. 3.2 Rejection of Batch
SJ 20275—93
If the test product is rejected, the manufacturer may rework the batch to correct the defects or remove the nonconforming products and then resubmit for inspection. The batches to be resubmitted for inspection shall be separated from the new batches and clearly marked as re-inspected batches. 4.5.1.3.3 Sample handling
Unless otherwise agreed between the supplier and the buyer, samples that have passed the Group B inspection shall not be delivered according to the contract. 4.5.1.4 Periodic inspection
Periodic inspection shall be composed of Group C inspection, and its items and sequence shall be specified in Table 6. Group C inspection samples shall be drawn from the inspection batches that have passed the Group A and Group B inspections.
4.5.1.4.1 Sampling
4.5.1.4.1.1 Monthly inspection
Monthly inspection includes two groups, C1a and C1b. Group C1a consists of 10 samples of any resistance value, and one unqualified sample is allowed during inspection. Group C1b consists of 10 samples (when double-lead terminals are inspected) or 20 samples (when single-lead terminals are inspected), and one unqualified sample is allowed each time. If there are more than 1 defective product in any group, re-inspection shall be carried out with double the number, and no defective products are allowed. 4.5.1.4.1.2 Quarterly inspection
Ten samples are selected from each of the three groups for quarterly inspection. The nominal zero-power resistance value of these samples should be between the minimum value and the middle value, and samples with smaller resistance values ​​are selected for C2b group test. During the test, one defective product is allowed in each group, but the total number of defective products in each group shall not exceed 1. 4.5.1.4.1.3 Half-year inspection
Ten samples with the highest resistance values ​​are allowed to have only one defective product during the half-year test. Table 6 C Group inspection
Test items
C1 group
C2 group
Cla group
End strength
Clb group
Weldability
C2a group
Resistance temperature characteristics
Temperature shock
Resistance to welding heat
C2h group
Load life
C2c Grouping
Long-term commercial temperature exposure
Number of samples for test
20 single leads or
10 double leads
Requirement clause
Elimination clause
Test item
C3 Grouping
Time constant
Dissipation coefficient
High-frequency vibration
4.5.1.4.2 Sample treatment
SJ 20275—93
Continued Table 6
Number of samples for test
Samples that have undergone Group C testing shall not be delivered according to the contract or order. 4.5.1.4.3 Failure
Request Clause
Method Clause
If the C group test fails, the manufacturer must take corrective measures for products with basically the same materials and processes, and products that are considered to have the same failure mechanism. At this time, the product should stop acceptance until the corrective measures taken are recognized by the competent department. After the corrective measures are taken, the products should be re-sampled for C group test (all items or only unqualified items, determined by the quality supervision department). Group A and Group B can also be re-tested. However, only when the results of the C group test re-test prove that the corrective measures are successful can the final acceptance be carried out. If it is still unqualified after re-testing, the relevant failure analysis and corrective measures should be provided to the appraisal agency. 4.5.1.4.4 Special treatment of C group inspection
When the product cannot be submitted for inspection on a monthly, quarterly or semi-annual basis, the same inspection can be used for appraisal inspection (see 4.4) after obtaining the opinion of the quality supervision department or the quality supervision department. Carry out according to the submitted batch. 4.5.2 Packaging Inspection
The inspection of packaging shall comply with the provisions of Chapter 5 of this specification. 4.6 Inspection Methods
4.6.1 Appearance and Mechanical Inspection (see 3.1, 3.3, 3.24 and 3.25) Appearance and mechanical inspection shall be carried out using instruments and methods with sufficient accuracy to verify that the design, structure, materials, dimensions, marking and processing quality meet the requirements of this specification. 4.6.2 Zero Power Resistance
4.6.2.1 Measurement Temperature and Accuracy All thermistors shall be measured in a homogeneous medium with a specified temperature and an accuracy of ±0.1°C (see 3.1).
4.6.2.2 Errors in the measurement methods:
a. Direct method for measuring the resistance value: should not exceed 10% of the allowable deviation of the zero-power resistance value: b. Indirect method for measuring the resistance value: should not exceed 10% of the maximum change in the zero-power resistance value: When using methods a and b to measure thermal resistors, the time response characteristics of the measuring device should be consistent with the test sample in accordance with the provisions of Article 4.6.2.1:
c. Instrument sensitivity The sensitivity of the instrument used should meet the test requirements. The time response characteristics of the test conditions should be consistent with the test sample.
4.6.2.3 The test procedure shall be carried out in accordance with the following provisions a. Installation Clamp the thermal resistor to a yellow rod with a diameter of 3mm in the prescribed manner. The distance from the clamping position to the end of the resistor body is 25.4±1.5mm; -9-
HTKAONTKAca-2 Acceptance of batches
If the test product is rejected, the manufacturer may take back the batch of products for return "corrective measures or eliminate non-conforming products, and then resubmit for inspection. The batch resubmitted for inspection should be separated from the new batch and clearly marked as a re-inspection batch. 4. 5. 1. 3 Group B inspection
Group B inspection should be carried out according to the tests and sequence specified in Table 5. Unless the quality supervision department proposes to draw a separate sample for Group B inspection, it should generally be drawn from the inspection batch that has passed the Group A inspection. Table 5 Group B Inspection
Test Items
Short-term Load
Insulation Resistance
Dielectric Withstand Voltage
Low-temperature Storage
High-temperature Storage
4.5.1.3.1 Sampling Order
Requirement Clause
Method Clause
Unless otherwise specified, the sampling procedures of this specification shall comply with the general inspection level I specified in GJB179: AQL and LQ are 4.0 and 18.0% respectively.
TYKAOKAca-
4. 5. 1. 3.2 Rejection of Batch
SJ 20275—93
If the test product is rejected, the manufacturer may rework the batch to correct the defects or remove the nonconforming products and then resubmit for inspection. The batches to be resubmitted for inspection shall be separated from the new batches and clearly marked as re-inspected batches. 4.5.1.3.3 Sample handling
Unless otherwise agreed between the supplier and the buyer, samples that have passed the Group B inspection shall not be delivered according to the contract. 4.5.1.4 Periodic inspection
Periodic inspection shall be composed of Group C inspection, and its items and sequence shall be specified in Table 6. Group C inspection samples shall be drawn from the inspection batches that have passed the Group A and Group B inspections.
4.5.1.4.1 Sampling
4.5.1.4.1.1 Monthly inspection
Monthly inspection includes two groups, C1a and C1b. Group C1a consists of 10 samples of any resistance value, and one unqualified sample is allowed during inspection. Group C1b consists of 10 samples (when double-lead terminals are inspected) or 20 samples (when single-lead terminals are inspected), and one unqualified sample is allowed each time. If there are more than 1 defective product in any group, re-inspection shall be carried out with double the number, and no defective products are allowed. 4.5.1.4.1.2 Quarterly inspection
Ten samples are selected from each of the three groups for quarterly inspection. The nominal zero-power resistance value of these samples should be between the minimum value and the middle value, and samples with smaller resistance values ​​are selected for C2b group test. During the test, one defective product is allowed in each group, but the total number of defective products in each group shall not exceed 1. 4.5.1.4.1.3 Half-year inspection
Ten samples with the highest resistance values ​​are allowed to have only one defective product during the half-year test. Table 6 C Group inspection
Test items
C1 group
C2 group
Cla group
End strength
Clb group
Weldability
C2a group
Resistance temperature characteristics
Temperature shock
Resistance to welding heat
C2h group
Load life
C2c Grouping
Long-term commercial temperature exposure
Number of samples for test
20 single leads or
10 double leads
Requirement clause
Elimination clause
Test item
C3 Grouping
Time constant
Dissipation coefficient
High-frequency vibration
4.5.1.4.2 Sample treatment
SJ 20275—93
Continued Table 6
Number of samples for test
Samples that have undergone Group C testing shall not be delivered according to the contract or order. 4.5.1.4.3 Failure
Request Clause
Method Clause
If the C group test fails, the manufacturer must take corrective measures for products with basically the same materials and processes, and products that are considered to have the same failure mechanism. At this time, the product should stop acceptance until the corrective measures taken are recognized by the competent department. After the corrective measures are taken, the products should be re-sampled for C group test (all items or only unqualified items, determined by the quality supervision department). Group A and Group B can also be re-tested. However, only when the results of the C group test re-test prove that the corrective measures are successful can the final acceptance be carried out. If it is still unqualified after re-testing, the relevant failure analysis and corrective measures should be provided to the appraisal agency. 4.5.1.4.4 Special treatment of C group inspection
When the product cannot be submitted for inspection on a monthly, quarterly or semi-annual basis, the same inspection can be used for appraisal inspection (see 4.4) after obtaining the opinion of the quality supervision department or the quality supervision department. Carry out according to the submitted batch. 4.5.2 Packaging Inspection
The inspection of packaging shall comply with the provisions of Chapter 5 of this specification. 4.6 Inspection Methods
4.6.1 Appearance and Mechanical Inspection (see 3.1, 3.3, 3.24 and 3.25) Appearance and mechanical inspection shall be carried out using instruments and methods with sufficient accuracy to verify that the design, structure, materials, dimensions, marking and processing quality meet the requirements of this specification. 4.6.2 Zero Power Resistance
4.6.2.1 Measurement Temperature and Accuracy All thermistors shall be measured in a homogeneous medium with a specified temperature and an accuracy of ±0.1°C (see 3.1).
4.6.2.2 Errors in the measurement methods:
a. Direct method for measuring the resistance value: should not exceed 10% of the allowable deviation of the zero-power resistance value: b. Indirect method for measuring the resistance value: should not exceed 10% of the maximum change in the zero-power resistance value: When using methods a and b to measure thermal resistors, the time response characteristics of the measuring device should be consistent with the test sample in accordance with the provisions of Article 4.6.2.1:
c. Instrument sensitivity The sensitivity of the instrument used should meet the test requirements. The time response characteristics of the test conditions should be consistent with the test sample.
4.6.2.3 The test procedure shall be carried out in accordance with the following provisions a. Installation Clamp the thermal resistor to a yellow rod with a diameter of 3mm in the prescribed manner. The distance from the clamping position to the end of the resistor body is 25.4±1.5mm; -9-
HTKAONTKAca-3 Half-year inspection
The 10 with the highest resistance! Only unqualified products are allowed when the samples are tested for half a year. Table 6 C group inspection
Test items
C1 group
C2 group
Cla group
End strength of lead
Clb group
Weldability
C2a group
Resistance temperature characteristics
Temperature shock
Resistance to welding heat
C2h group
Load life
C2c Grouping
Long-term commercial temperature exposure
Number of samples for test
20 single leads or
10 double leads
Requirement clause
Elimination clause
Test item
C3 Grouping
Time constant
Dissipation coefficient
High-frequency vibration
4.5.1.4.2 Sample treatment
SJ 20275—93
Continued Table 6
Number of samples for test
Samples that have undergone Group C testing shall not be delivered according to the contract or order. 4.5.1.4.3 Failure
Request Clause
Method Clause
If the C group test fails, the manufacturer must take corrective measures for products with basically the same materials and processes, and products that are considered to have the same failure mechanism. At this time, the product should stop acceptance until the corrective measures taken are recognized by the competent department. After the corrective measures are taken, the products should be re-sampled for C group test (all items or only unqualified items, determined by the quality supervision department). Group A and Group B can also be re-tested. However, only when the results of the C group test re-test prove that the corrective measures are successful can the final acceptance be carried out. If it is still unqualified after re-testing, the relevant failure analysis and corrective measures should be provided to the appraisal agency. 4.5.1.4.4 Special treatment of C group inspection
When the product cannot be submitted for inspection on a monthly, quarterly or semi-annual basis, the same inspection can be used for appraisal inspection (see 4.4) after obtaining the opinion of the quality supervision department or the quality supervision department. Carry out according to the submitted batch. 4.5.2 Packaging Inspection
The inspection of packaging shall comply with the provisions of Chapter 5 of this specification. 4.6 Inspection Methods
4.6.1 Appearance and Mechanical Inspection (see 3.1, 3.3, 3.24 and 3.25) Appearance and mechanical inspection shall be carried out using instruments and methods with sufficient accuracy to verify that the design, structure, materials, dimensions, marking and processing quality meet the requirements of this specification. 4.6.2 Zero Power Resistance
4.6.2.1 Measurement Temperature and Accuracy All thermistors shall be measured in a homogeneous medium with a specified temperature and an accuracy of ±0.1°C (see 3.1).
4.6.2.2 Errors in the measurement methods:
a. Direct method for measuring the resistance value: should not exceed 10% of the allowable deviation of the zero-power resistance value: b. Indirect method for measuring the resistance value: should not exceed 10% of the maximum change in the zero-power resistance value: When using methods a and b to measure thermal resistors, the time response characteristics of the measuring device should be consistent with the test sample in accordance with the provisions of Article 4.6.2.1:
c. Instrument sensitivity The sensitivity of the instrument used should meet the test requirements. The time response characteristics of the test conditions should be consistent with the test sample.
4.6.2.3 The test procedure shall be carried out in accordance with the following provisions a. Installation Clamp the thermal resistor to a yellow rod with a diameter of 3mm in the prescribed manner. The distance from the clamping position to the end of the resistor body is 25.4±1.5mm; -9-
HTKAONTKAca-3 Half-year inspection
The 10 with the highest resistance! Only unqualified products are allowed when the samples are tested for half a year. Table 6 C group inspection
Test items
C1 group
C2 group
Cla group
End strength of lead
Clb group
Weldability
C2a group
Resistance temperature characteristics
Temperature shock
Resistance to welding heat
C2h group
Load life
C2c Grouping
Long-term commercial temperature exposure
Number of samples for test
20 single leads or
10 double leads
Requirement clause
Elimination clause
Test item
C3 Grouping
Time constant
Dissipation coefficient
High-frequency vibration
4.5.1.4.2 Sample treatment
SJ 20275—93
Continued Table 6
Number of samples for test
Samples that have undergone Group C testing shall not be delivered according to the contract or order. 4.5.1.4.3 Failure
Request Clause
Method Clause
If the C group test fails, the manufacturer must take corrective measures for products with basically the same materials and processes, and products that are considered to have the same failure mechanism. At this time, the product should stop acceptance until the corrective measures taken are recognized by the competent department. After the corrective measures are taken, the products should be re-sampled for C group test (all items or only unqualified items, determined by the quality supervision department). Group A and Group B can also be re-tested. However, only when the results of the C group test re-test prove that the corrective measures are successful can the final acceptance be carried out. If it is still unqualified after re-testing, the relevant failure analysis and corrective measures should be provided to the appraisal agency. 4.5.1.4.4 Special treatment of C group inspection
When the product cannot be submitted for inspection on a monthly, quarterly or semi-annual basis, the same inspection can be used for appraisal inspection (see 4.4) after obtaining the opinion of the quality supervision department or the quality supervision department. Carry out according to the submitted batch. 4.5.2 Packaging Inspection
The inspection of packaging shall comply with the provisions of Chapter 5 of this specification. 4.6 Inspection Methods
4.6.1 Appearance and Mechanical Inspection (see 3.1, 3.3, 3.24 and 3.25) Appearance and mechanical inspection shall be carried out using instruments and methods with sufficient accuracy to verify that the design, structure, materials, dimensions, marking and processing quality meet the requirements of this specification. 4.6.2 Zero Power Resistance
4.6.2.1 Measurement Temperature and Accuracy All thermistors shall be measured in a homogeneous medium with a specified temperature and an accuracy of ±0.1°C (see 3.1).
4.6.2.2 Errors in the measurement methods:
a. Direct method for measuring the resistance value: should not exceed 10% of the allowable deviation of the zero-power resistance value: b. Indirect method for measuring the resistance value: should not exceed 10% of the maximum change in the zero-power resistance value: When using methods a and b to measure thermal resistors, the time response characteristics of the measuring device should be consistent with the test sample in accordance with the provisions of Article 4.6.2.1:
c. Instrument sensitivity The sensitivity of the instrument used should meet the test requirements. The time response characteristics of the test conditions should be consistent with the test sample.
4.6.2.3 The test procedure shall be carried out in accordance with the following provisions a. Installation Clamp the thermal resistor to a yellow rod with a diameter of 3mm in the prescribed manner. The distance from the clamping position to the end of the resistor body is 25.4±1.5mm; -9-
HTKAONTKAca-
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