This standard specifies the classification, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of guitar strings. This standard applies to all kinds of guitar strings, and guitar strings not mentioned in this standard should also be used as a reference. QB/T 1817-1993 General Technical Requirements for Guitar Strings QB/T1817-1993 Standard download decompression password: www.bzxz.net

Light Industry Industry Standard of the People's Republic of China
General Technical Conditions for Strings
1 Subject Content and Applicable Models
QB/T1817—1993
This standard specifies the classification, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of strings. This standard applies to all kinds of strings, and strings not mentioned in this standard should also be used as a reference. 2 Reference Standards
GB/T2828 Batch Inspection Count Sampling Procedure and Sampling Table (Applicable to Inspection of Continuous Batch) GB/T2829 Periodic Inspection Count Sampling Procedure and Sampling Table (Applicable to Inspection of Stability of Production Process) GB5926 Appearance Quality Test Method for Metal Coating and Chemical Treatment Layer of Light Industrial Products GB/T6388 Shipping and Receiving Marks for Transport Packages
3 Product Classification
3.1 According to different structural characteristics, it is divided into bare strings and wound strings. 3.2 According to different process quality and main uses, it is divided into high-end products, intermediate products and popular products. 3.3 According to the different materials, they are divided into metal strings, nylon strings, silk strings, etc. 3.4 According to the different strengths of metal strings, high-end products are divided into three types: soft, medium and hard. There is no distinction between medium-end products and popular products. 4 Technical requirements
4.1 Standard sound
The sound a in the small letter group is 440Hz.
4.2 In addition to the timbre, tuning pitch, broken pitch, specifications and dimensions, diameter uniformity allowable deviation and physical properties that must comply with the corresponding product standards, the appearance must meet the following requirements.
Nylon bare strings should be smooth and straight in appearance;
Metal bare strings should be smooth, straight, and free of rust, with smooth and loose velvet; c.
The wound strings should be evenly and firmly wound, without cracks, looseness, protrusions, black spots or discoloration, and the metal string wire should be free of rust; d.
Silk strings should have a uniform color, flat and even hooks, uniform tightness, and no obvious numbness, pinching or other defects. 5 Test method
5.1 Acoustic quality
Tone: Put strings of different grades on instruments of corresponding grades that meet the quality standards of this variety, and have the corresponding grade of performers play and perform sensory inspection.
5.2 Specifications, dimensions and diameter uniformity allowable deviation 5.2.1 String length
Check with a length gauge with an accuracy of not less than 1mm. 5.2.2 Diameter average hook tolerance
Approved by the Ministry of Light Industry of the People's Republic of China on July 29, 1993 38
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Implemented on March 1, 1994
QB/T 1817-1993
Inspect with a micrometer within the effective string length range. For high-end products, measure at least three points for each string, and for mid-range and popular products, measure at least two points for each string. Take the algebraic sum of the two extreme values. 5.2.3 Wire wrapping size
Check with a length gauge with an accuracy of not less than 1mm. 5.3 Physical properties
5.3.1 Minimum breaking pitch
Install the string on the instrument or on a special testing instrument and check with a pitch meter. 5.3.2 Tension and elongation
5.3.2.1 Install the string on the special testing instrument shown in Figure 1. The distance between the nut and the bridge is the effective string length. Use a load of 4.9N to straighten the string and mark the color mark on the string at the point of contact with the bridge. 1- nut; 2- string; 3- bridge, 4- load Figure 1
5.3.2.2 Add load to make the string reach the tuning pitch. The load is the tension of the string. 5.3.2.3 Use a length gauge with an accuracy of not less than 0.02mm to measure the distance between the color mark point of the string and the point of contact with the bridge. This distance is the absolute elongation of the string.
5.3.2.4 The effective string length of the violin is 327mm, the effective string length of the viola is 367mm, the effective string length of the cello is 700mm, and the effective string length of the double cello is 1125mm. The effective string length of other stringed instruments shall meet the requirements of product standards. 5.3.2.5 Calculation of total tension and elongation of each string The total tension of each string shall be calculated according to formula (1):
Where: T——total tension of each string, N,
T; tension of each string, N.
Elongation of each string shall be calculated according to formula (2):
Where: —elongation of each string, %;
Al——absolute elongation of each string, mm;
1—effective string length of each string, mm.
5.4 Appearance
(1)
Sensory inspection: metal strings shall meet the requirements of Chapter 2 of GB5926. 2)
6 Inspection rules
QB/T 1817—1993
6.1 Products shall be inspected and accepted by the purchasing department or entrusted to the quality management department of the manufacturer for inspection. Qualified products shall be accompanied by product certificates and indicate the number of the corresponding relevant standards that the product complies with before they can leave the factory. 6.2 When there are special requirements for the product, the specific inspection items shall be negotiated by the supply and demand parties according to the contract. 6.3 Product inspection is divided into delivery inspection and routine inspection. 6.3.1 The sampling plan for delivery inspection shall comply with the provisions of GB/T2828 on the normal inspection sampling plan. 6.3.2 The items, inspection level and qualified quality level (AQL) of delivery inspection shall comply with the provisions of Table 1. Table 1
Inspection items
String length
Diameter uniformity allowable deviation
Wire size
Test method
General inspection level
Qualified quality level (AQL)
6.3.3 Routine inspection of products shall be carried out once a year, and shall also be carried out when the structure, manufacturing process and main raw materials are changed or when production is resumed after a suspension of more than three months.
6.3.4 The samples for routine inspection shall be randomly selected from the products currently produced and qualified by the delivery inspection. 6.3.5 The sampling plan for routine inspection shall comply with the provisions of the sub-sampling plan for discrimination level 1 in GB/T2829. 6.3.6 All samples taken for routine inspection shall be inspected according to the delivery inspection items first. If there are unqualified products, they shall be replaced with qualified products and the reasons shall be analyzed at the same time, but they shall not be used as the basis for routine inspection results. 6.3.7 Routine inspection shall be carried out according to all technical indicators listed in this standard and the corresponding product standards. The judgment array is (1,2) and the unqualified quality level (RQL) is 50.
6.3.8 If the routine inspection is qualified, the products produced in this cycle are qualified products. 6.3.9 Samples that have passed routine inspection shall not be shipped as delivered products. 7 Marking, packaging, transportation, purchase and storage
7.1. Small package
7.1.1 Each string is packed with corresponding materials according to different grades, and the packaging materials should have moisture-proof function. 7.1.2 Every ten strings are packed into a small bundle, and the export is packed in "dozens" or "sets". 7.2 Large package
7.2.1 Packed with cartons according to actual needs, the packaging materials should have moisture-proof function. 7.3 Mark
7.3.1 The small package should have the manufacturer's name, trademark, factory address, product name, string name, model and qualified words or logos. 7.3.2 In addition to meeting the requirements of GB/T6388, the large package should also have the trademark, factory address and other words or logos. 7.4 Transportation
The product should not be exposed to rain or pressed by heavy objects during transportation. 7.5 Storage
The product should be placed in a dry and ventilated room and should not be exposed to moisture. 7.6 If the product meets the above conditions, the shelf life is one year. 40bzxz.net
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Additional instructions:
This standard is proposed by the Quality Standards Department of the Ministry of Light Industry. This standard is under the jurisdiction of the National Musical Instrument Standardization Center. QB/T1817—1993
This standard was drafted by Guangzhou Qinxian Factory and the National Musical Instrument Standardization Center. The main drafters of this standard are Li Lin, Mai Bietang, Lu Chen, and Wang Wei.
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