Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:13:p34
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 13 (pt 34/56)
Character Range: 390069–392785

HCLD shall be calibrated in the most common operating range following the manufacturer's specifications using zero and span gas (the NO content of which shall amount to about 80 per cent of the operating range and the NO2 concentration of the gas mixture to less than 5 per cent of the NO concentration). The NOx analyzer shall be in the NO mode so that the span gas does not pass through the converter. The indicated concentration has to be recorded.
9.3.6.3. Calculation
 The per cent efficiency of the converter shall be calculated as follows:

  (72)
 Where:
a is the NOx concentration according to paragraph 9.3.6.6.
b is the NOx concentration according to paragraph 9.3.6.7.
c is the NO concentration according to paragraph 9.3.6.4.
d is the NO concentration according to paragraph 9.3.6.5.
9.3.6.4. Adding of oxygen
 Via a T-fitting, oxygen or zero air shall be added continuously to the gas flow until the concentration indicated is about 20 per cent less than the indicated calibration concentration given in paragraph 9.3.6.2. (the analyzer is in the NO mode).
 The indicated concentration (c) shall be recorded. The ozonator is kept deactivated throughout the process.
9.3.6.5. Activation of the ozonator
 The ozonator shall be activated to generate enough ozone to bring the NO concentration down to about 20 per cent (minimum 10 per cent) of the calibration concentration given in paragraph 9.3.6.2. The indicated concentration (d) shall be recorded (the analyzer is in the NO mode).
9.3.6.6. NOx mode
 The NO analyzer shall be switched to the NOx mode so that the gas mixture (consisting of NO, NO2, O2 and N2) now passes through the converter. The indicated concentration (a) shall be recorded (the analyzer is in the NOx mode).
9.3.6.7. Deactivation of the ozonator
 The ozonator is now deactivated. The mixture of gases described in paragraph 9.3.6.6. passes through the converter into the detector. The indicated concentration (b) shall be recorded (the analyzer is in the NOx mode).
9.3.6.8. NO mode
 Switched to NO mode with the ozonator deactivated, the flow of oxygen or synthetic air shall be shut off. The NOx reading of the analyzer shall not deviate by more than ±5 per cent from the value measured according to paragraph 9.3.6.2. (the analyzer is in the NO mode).
9.3.6.9. Test interval
 The efficiency of the converter shall be tested at least once per month.
9.3.6.10. Efficiency requirement
 The efficiency of the converter ENOx shall not be less than 95 per cent.
 If, with the analyzer in the most common range, the ozonator cannot give a reduction from 80 per cent to 20 per cent according to paragraph 9.3.6.5., the highest range which will give the reduction shall be used.
9.3.7.