# BS ISO 02971:2013 pdf download

BS ISO 02971:2013 pdf download.Cigarettes and filter rods ——Determination of nominal diameter -Method using anon-contact optical measuring apparatus.

The time required for the curing of (liter rods and the duration of conditioning for both filter rods and cigarettes are not specified in this International Standard and are to be determined by practical experience. They shall be reported in the test report together with the results.

7.2 Adlustment and calibration

Working standards are routinely used to adjust calibrate or check the calibration of the measurement system. Calibration shall be performed in accordance with the manufacturer’s instructions.

NOTE The essential properties of calibration standards are given In Annex A.

7.3 Measurement

In accordance with the manufacturer’s instructions, position the test piece within the measurement area, as close as possible to the centre of the measurement area.

The test piece. or the measuring apparatus, shall be capable of being rotated around the rotation axis such that any eccentric motion of the test piece, relative to the plane of the measurement, remains in parallel with the plane of the measurement and perpendicular to the longitudinal axis of the test piece.

Adjust the instrument and/or feeding and rotational apparatus br the plane of the measurement to measure the required section of the test piece.

Operate the apparatus in accordance with the manufacturer’s instructions and accurately record the mean, minimum and maximum diameters.

At least 10 test pieces trom one sample shall be used to determine the mean value ot the diameter for the sample.

NOTE I In practice, laboratories often take a different number of measurements depending on the application or the measuremeni

NOTE 2 PossIble sources of error In measurement of diameter are given in Annex C.

8 Expression of results

The value of the sample mean diameter shall be the mean value of the individual measurements. See L.

The results shall be expressed as follows:

a) diameter, the arithmetic average of at least 64 individual scans per lull revolution or 32 scans per half revolution. is expressed in millimetres to the nearest OO1 mm;

b) sample mean diameter, the average of x diameter measurements (xis normally 10 but may vary; see note I in 7.3) is expressed In millimetres to the nearest 0,001 mm;

c) sample maximum diameter, the maximum diameter obtained from a sample of x test pieces, is expressed in millimetres to the nearest 0,01 mm;

d) sample minimum diameter, the minimum diameter obtained from a sample of x test pieces, is expressed in millimetres to the nearest 0,01 mm;

e) absolute ovallty Is expressed In millimetres to the nearest 0,01 mm;

f) relative ovality is expressed as a percentage to the nearest 0,1 %;

g) relative roundness is expressed as a percentage to the nearest 0,1 %.

9 Repeatability and reproducibility

An lntcrnatlonal collaborative study InvolvIng 14 laboratorIes was conducted according to Iso 5725-2:1994 in 2009 on matched samples of both filter rods and cigarettes covering a range of approximately 5 mm to 9 mm diameter.

Each measured sample was drawn randomly from a population of typically 3000 rods that, as far as was possible, represented a consistent production process. Three samples of 10 rods, plus spares, were distributed to each participant Each sample of 10 rods was measured once only. The measurement position for the cigarettes was specified to be on the tobacco column. The measurement position for the filters was not specified.

NOTE I Specific details of the measurement protocol are given in Annexf.

The study gave the following values (see Table 1) for mean diameter, repeatability standard deviation (Sr, reproducibility standard deviation (SR), repeatability limit (r) and reproducibility limit (R). The values derived from this interlaboratory study may not be applicable to values and matrices other than those given because the samples being used did not cover all available products.