ISO 2403 pdf download

ISO 2403 pdf download Textiles — Cotton fibres — Determination of micronaire value
1 Scope
ThisInternationalStandardspecifies a method ofdeterminingthe micronairevalue ofloose disorientatedcotton fibres taken from bales, laps and slivers, or other sources of lint cotton.
2 Normative references
The following documents,in whole or in part, are normatively referenced in this document and areindispensable for its application. For dated references, only the edition cited applies. For undatedreferences, the latest edition ofthe referenced document (including any amendments) applies.
ISO 139, Textiles – Standard atmospheres for conditioning and testingISO 1130, Textile fibres – Some methods ofsampling for testing
3Terms and definitions
For the purposes of this document, the following terms and definitions apply.31
micronaire valuemeasure ofthe air permeability ofa mass of cotton under specified conditions, expressed in terms ofanarbitrary scale, the so-called micronaire scale
Note 1 to entry: The micronaire scale is based on arange ofcottons to which micronaire values have been assignecby internationalagreement.
4 Principle
Air is passed through a test specimen consisting of a plug of fibres. The permeability is indicated on ascale for recording variations in either the rate of flow through, or the pressure difference across, theplug. The mass and volume of the test specimen are either a constant for a given type of instrument orvaried appropriately in relation to each other. The scale indicating variations in permeability can becalibrated in arbitrary units of micronaire valu or marked in the appropriate absolute units of rate offlow or of pressure difference and a table or graph provided for conversion of the observed readings intomicronaire values.
5 Apparatus and materials
5.1Balance of sufficient capacity to weigh the test specimen required for the airflow instrument usedwith an accuracy of+0,2 %.
5.2Airflow instrument, whose principal parts are:
5.2.1 Compression cylinder with perforated ends of such dimensions that with the prescribed mass ofspecimen each cubic centimetre shall contain between 0,16 g and 0,30 g of cotton when compressed.
5.2.2Means for measuring the air permeability of the specimen, comprising, for example:
a suitable air pump;a
6one or more valves or other means for controlling the flow of air through, or the pressure differenceacross, the specimen in the compression cylinder;
a manometer for measuring the required air pressure difference across the specimen and aflowmeter for indicating the rate of airflow through it.
NOTEDetails of certain commercially available instruments which comply with this specification are givenin the Appendices to this International Standard.The method of calibration of airflow instruments is described inAnnex A.
53International calibration cotton standards (see A.1)
Atmosphere for conditioning and testing
6.1 Condition test samples in the standard atmosphere for 4 h in moving air (or alternatively for 12 h instill air) or for a shorter time if the change in mass in a 2 h period does not exceed 0,25 % before weighingand testing the specimen. Preconditioning is not required.
6.2Weigh and test the specimen in the standard atmosphere for conditioning (see ISO 139)
7 Test Specimen
71 Take test specimens in accordance with the instructions given in ISO 1130, or specimens andsamples can be drawn in other ways with prior agreement between the parties concerned.