Document ID: chunk:federal_register_of_legislation:F2011C00805:reg:120:p12
Version: federal_register_of_legislation:F2011C00805
Segment Type: reg
Provision Reference: reg 120 (pt 12/23)
Character Range: 266258–269339

will be required to ensure constant flow through the venturi (Mv) and thus proportional flow through S3 particulate sampling system.

               S4 Sampling probe in dilution tunnel,

               Fp Filter unit, consisting of two series-mounted filters; switching unit for further parallel-mounted pairs of filters,

         Sampling line,

         Pumps, flow regulators, flow measuring units.

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Annex 4 - Appendix 6

METHOD OF CALIBRATING THE EQUIPMENT

         1. ESTABLISHMENT OF THE CALIBRATION CURVE

         1.1. Each normally used operating range is calibrated in accordance with the requirements of paragraph 4.3.3. of Annex 4 by the following procedure:

         1.2. The analyser calibration curve is established by at least five calibration points spaced as uniformly as possible. The nominal concentration of the calibration gas of the highest concentration shall be not less than 80 per cent of the full scale.

         1.3. The calibration curve is calculated by the least squares method.  If the resulting polynomial degree is greater than 3, the number of calibration points shall be at least equal to this polynomial degree plus 2.

         1.4. The calibration curve shall not differ by more than  2 per cent from the nominal value of each calibration gas.

         1.5. Trace of the calibration curve

         From the trace of the calibration curve and the calibration points, it is possible to verify that the calibration has been carried out correctly. The different characteristic parameters of the analyser shall be indicated, particularly:

              the scale,
              the sensitivity,
              the zero point,
              the date of carrying out the calibration.

         1.6. If it can be shown to the satisfaction of the technical service that alternative technology (e.g. computer, electronically controlled range switch, etc.) can give equivalent accuracy, then these alternatives may be used.

         1.7. Verification of the calibration

         1.7.1. Each normally used operating range shall be checked prior to each analysis in accordance with the following:

         1.7.2.  The calibration shall be checked by using a zero gas and a span gas whose nominal value is within 80-95 per cent of the supposed value to be analysed.

         1.7.3.  If, for the two points considered, the value found does not differ by more than  5 per cent of the full scale from the theoretical value, the adjustment parameters may be modified. Should this not be the case, a new calibration curve shall be established in accordance with paragraph 1 of this Appendix.

         1.7.4. After testing, zero gas and the same span gas are used for re-checking. The analysis is considered acceptable if the difference between the two measuring results is less than 2 per cent.

         2. CHECKING FOR FID HYDROCARBON RESPONSE

         2.1.  Detector response optimisation

         The FID shall be adjusted, as specified by the instrument manufacturer. Propane in air should be used, to optimise the response, on