Division 9.3.2.1 Sampling probes

Either single-port or multi-port probes are used for sampling gaseous emissions. The probes may be oriented in any direction relative to the raw or diluted exhaust gas flow. For some probes, the sample temperatures shall be controlled, as follows:

1. (a)

   For probes that extract NO_x from diluted exhaust gas, the probe's wall temperature shall be controlled to prevent aqueous condensation;

2. (b)

   For probes that extract hydrocarbons from the diluted exhaust gas, a probe wall temperature is recommended to be controlled approximately 191 °C to minimise contamination.