ISO 2061:2015规定了一种通过直接计数法确定纱线的加捻方向、以每单位长度的匝数表示的加捻量以及退捻时的长度变化的方法。 本国际标准适用于 a)单纱(纺纱和长丝)， b)合股纱线，和 c)缆线纱线。 为每种类型的纱线给出了单独的程序。该方法主要针对包装中的纱线而设计，但是，在采取特殊预防措施的情况下，该程序也可用于从织物中取出的纱线。它不适用于测定单丝的捻度。 注另见专门为玻璃纺织技术的需要而编制的ISO 1890和ISO 7211？4. ISO 2061:2015涵盖合股纱线和缆线纱线捻度的测定如下:a)合股纱线中:合股纱线的最终捻度和合股前单纱的原始捻度； b)在缆线纱线中: ？纱线的最终电缆捻度； ？合股纱线在合股后但在加工的最后阶段之前的原始捻度； ？合股前单纱的捻度。 如果需要，可以通过10.5.7中给出的特殊程序确定最终结构中的单股和合股纱线组件的捻度。 ISO 2061:2015不适用于当张力从每单位纱线线密度0.5 cN增加到1.0 cN（以tex表示）时拉伸超过0.5%的纱线，除非有协议。这种纱线可以在特殊的张力条件下进行测试，所述张力条件被对测试结果感兴趣的各方所接受。 ISO 2061:2015不适用于开口纺和混纺（交织）复丝纱线的产品。 ISO 2061:2015不适用于纱线，这些纱线太大，无法在没有严重到足以影响测试结果的压碎或变形的情况下放置在测试设备的夹具中。

ISO 2061:2015 specifies a method for the determination of the direction of twist in yarns, the amount of twist, in terms of turns per unit length, and the change in length on untwisting, by the direct counting method. This International Standard is applicable to a) single yarns (spun and filament), b) plied yarns, and c) cabled yarns. Separate procedures are given for each type of yarn. The method is designed primarily for yarns in packages, but, with special precautions, the procedures can be used for yarns taken from fabrics. It is not suitable for the determination of twist in a monofilament. NOTE See also ISO 1890, which was prepared especially for the needs of glass textile technology, and ISO 7211？4. ISO 2061:2015 covers the determination of twist in plied and cabled yarns as follows: a) in plied yarns: the final twist of the plied yarns and the original twist of the single yarn before plying; b) in cabled yarns:

• ? the final cabling twist of the yarn;
• ? the original twist of the plied yarn after plying, but prior to the last stage of processing;
• ? the twist of the single yarn before plying.

If desired, the twist of single and plied yarn components, as they lie in the final structure, can be determined by the special procedure given in 10.5.7. ISO 2061:2015 is not applicable, except by agreement, to yarns which stretch more than 0,5 % when the tension increases from 0,5 cN to 1,0 cN per unit linear density of the yarn expressed in tex. Such yarns can be tested under special conditions of tension which are accepted by all parties interested in the test results. ISO 2061:2015 is not suitable for products of open-end spinning and intermingled (interlaced) multifilament yarns. ISO 2061:2015 is not applicable to yarns which are too large to permit their being placed in the clamps of the testing apparatus without crushing or distortion severe enough to affect the test results.