Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:9:p26
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 9 (pt 26/37)
Character Range: 1850944–1854009

FID shall be adjusted as specified by the instrument manufacturer. Propane in air should be used to optimise the response on the most common operating range.
              4.3.3.2. Calibration of the hydrocarbon analyser
               The analyser should be calibrated using propane in air and purified synthetic air. See paragraph 6.2. of Annex B5 of this Regulation.
               Each of the normally used operating ranges are calibrated in accordance with paragraphs 4.3.3.2.1. to 4.3.3.2.4. of this annex.
              4.3.3.2.1. Establish the calibration curve by at least five calibration points spaced as evenly as possible over the operating range. The nominal concentration of the calibration gas with the highest concentrations to be at least 80 per cent of the full scale.
              4.3.3.2.2. Calculate the calibration curve by the method of least squares. If the resulting polynomial degree is greater than 3, then the number of calibration points shall be at least the number of the polynomial degree plus 2.
              4.3.3.2.3. The calibration curve shall not differ by more than 2 per cent from the nominal value of each calibration gas.
              4.3.3.2.4. Using the coefficients of the polynomial derived from paragraph 5 of Annex B5, a table of indicated reading against true concentration shall be drawn up in steps of no greater than 1 per cent of full scale. This is to be carried out for each analyser range calibrated. The table shall also contain other relevant data such as:
                  (a) Date of calibration, span and zero potentiometer readings (where applicable);
                  (b) Nominal scale;
                  (c) Reference data of each calibration gas used;
                  (d) The actual and indicated value of each calibration gas used together with the percentage differences;
                  (e) FID fuel and type;
                  (f) FID air pressure.
              4.3.3.2.5. If it can be shown to the satisfaction of the responsible authority that alternative technology (e.g. computer, electronically controlled range switch) can give equivalent accuracy, then those alternatives may be used.
              4.4. Temperature recording system
              The temperature recording system shall meet the requirements of paragraphs 4.4.1. to 4.4.5. of this annex.
              4.4.1. The temperature in the chamber is recorded at two points by temperature sensors which are connected so as to show a mean value. The measuring points are extended approximately 0.1 m into the enclosure from the vertical centre line of each side wall at a height of 0.9 ± 0.2 m.
              4.4.2. The temperatures of the fuel tank(s) are recorded by means of the sensor positioned in the fuel tank as in paragraph 6.1.1. of this annex in the case of use of the gasoline canister load option (paragraph 6.5.5.3. of this annex).
              4.4.3. Temperatures shall, throughout the evaporative emission measurements, be recorded or entered into a data processing system at a frequency of at least once