Division 9.4.3.2 Component requirements
United Kingdom
Table 6.8 shows the specifications of transducers of torque, speed, and pressure, sensors of temperature and dew point, and other instruments. The overall system for measuring the given physical and/or chemical quantity shall meet the linearity verification in point 8.1.4. For gaseous emissions measurements, analyzers may be used, that have compensation algorithms that are functions of other measured gaseous components, and of the fuel properties for the specific engine test. Any compensation algorithm shall only provide offset compensation without affecting any gain (that is no bias).
Table 6.8
Recommended performance specifications for measurement instruments
| Accuracy and repeatability are all determined with the same collected data, as described in point 9.4.3, and based on absolute values. ‘pt.’ refers to the overall mean value expected at the emission limit; ‘max.’ refers to the peak value expected at the emission limit over the duty cycle, not the maximum of the instrument's range; ‘meas.’ refers to the actual mean measured over the duty cycle. | |||||
| Measurement Instrument | Measured quantity symbol | Complete SystemRise time | Recording update frequency | Accuracyf1 | Repeatability |
|---|---|---|---|---|---|
| Engine speed transducer | n | 1 s | 1 Hz means | 2,0 % of pt. or 0,5 % of max | 1,0 % of pt. or 0,25 % of max |
| Engine torque transducer | T | 1 s | 1 Hz means | 2,0 % of pt. or 1,0 % of max | 1,0 % of pt. or 0,5 % of max |
| Fuel flow meter (Fuel totalizer) | 5 s (N/A) | 1 Hz (N/A) | 2,0 % of pt. or 1,5 % of max | 1,0 % of pt. or 0,75 % of max | |
| Total diluted exhaust gas meter (CVS) (With heat exchanger before meter) | 1 s (5 s) | 1 Hz means (1 Hz) | 2,0 % of pt. or 1,5 % of max | 1,0 % of pt. or 0,75 % of max | |
| Dilution air, inlet air, exhaust gas, and sample flow meters | 1 s | 1 Hz means of 5 Hz samples | 2,5 % of pt. or 1,5 % of max | 1,25 % of pt. or 0,75 % of max | |
| Continuous gas analyzer raw | x | 5 s | 2 Hz | 2,0 % of pt. or 2,0 % of meas. | 1,0 % of pt. or 1,0 % of meas. |
| Continuous gas analyzer dilute | x | 5 s | 1 Hz | 2,0 % of pt. or 2,0 % of meas. | 1,0 % of pt. or 1,0 % of meas. |
| Continuous gas analyzer | x | 5 s | 1 Hz | 2,0 % of pt. or 2,0 % of meas. | 1,0 % of pt. or 1,0 % of meas. |
| Batch gas analyzer | x | N/A | N/A | 2,0 % of pt. or 2,0 % of meas. | 1,0 % of pt. or 1,0 % of meas. |
| Gravimetric PM balance | m PM | N/A | N/A | See 9.4.11 | 0,5 μg |
| Inertial PM balance | m PM | 5 s | 1 Hz | 2,0 % of pt. or 2,0 % of meas. | 1,0 % of pt. or 1,0 % of meas. |
Annotations
Footnotes
- f1
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Accuracy and repeatability are all determined with the same collected data, as described in point 9.4.3, and based on absolute values. ‘pt.’ refers to the overall mean value expected at the emission limit; ‘max.’ refers to the peak value expected at the emission limit over the duty cycle, not the maximum of the instrument's range; ‘meas.’ refers to the actual mean measured over the duty cycle.