Have a wall temperature sufficiently above the dew point of the exhaust gas to prevent condensation.

During a prescribed sequence of warmed-up engine operating conditions the amounts of the above exhaust emissions shall be examined continuously by taking a sample from the raw exhaust gas.

MTOTW= total mass of diluted exhaust gas over the cycle as determined in Section 4.1, kg

The differential pressure of the exhaust gas between exhaust pipe and inlet to the probe is measured with the pressure transducer DPT.

shall be of a sufficient length to cause complete mixing of the exhaust and dilution air under turbulent flow conditions;

The opacimeter shall be mounted centrally to the plume within 25 ± 5 mm of the end of the exhaust pipe.

Direct measurement of the exhaust flow by flow nozzle or equivalent metering system;

start measuring the amount of diluted exhaust gas (CVS) and the required temperatures and pressures;

The CO2 concentrations are measured in the diluted exhaust gas and in the dilution air with the exhaust gas analyser(s) EGA.

With the partial flow opacimeter (Figure 24), a representative exhaust sample is taken from the exhaust pipe and passed through a transfer line to the measuring chamber.

The exhaust gas flow GEXHW or the diluted exhaust gas flow GTOTW, if used optionally, shall be determined in accordance with Annex III, Appendix 4, section 2.3.

At the completion of the test, the measurement of the diluted exhaust gas volume, the gas flow into the collecting bags and the particulate sample pump shall be stopped.

Exhaust emissions approval of an engine running on natural gas or LPG and laid out for operation on one specific fuel composition

The PDP meters total diluted exhaust flow from the number of the pump revolutions and the pump displacement.

CFV measures total diluted exhaust flow by maintaining the flow at choked conditions (critical flow).

The pressure of the exhaust gas in the smoke chamber shall not differ by more than 75 mm (water gauge) from the atmospheric pressure.

adjusting the suction blower SB to a constant mass flow of the diluted exhaust gas and controlling the flow of the pressure blower PB, and therefore the exhaust sample flow in a region at the end of the transfer tube TT (Figure 12).

Flow diagram of raw exhaust gas analysis system for CO, CO2, NOx, HC ESC only

A control system is necessary for isokinetic exhaust splitting by maintaining a differential pressure of zero between EP and ISP.

The engine exhaust shall be directed downstream at the point where it is introduced into the dilution tunnel, and thoroughly mixed.

be installed in the dilution tunnel DT (see section 2.3, Figure 20) at a point where the dilution air and exhaust gas are well mixed (i.e. approximately 10 tunnel diameters downstream of the point where the exhaust enters the dilution tunnel);

Be as short as possible and ensure an exhaust gas temperature of 373 ± 30 K (100 °C ± 30 °C) at the entrance to the measuring chamber.

The carbon monixide content of the exhaust emissions of petrol driven vehicles equipped with certain exhaust after-treatment systems (Euro 1 standard) need to be tested at both low and high engine speeds.

Since particulate mass determination is based on the total diluted exhaust gas flow, the dilution ratio is not required to be calculated.

However, the dilution air temperature must not exceed 325 K (52 °C) prior to the introduction of the exhaust in the dilution tunnel.

Measurement of the air flow and the fuel flow by suitable metering systems and calculation of the exhaust flow by the following equation:

maintain a wall temperature greater than 453 K (180 °C), if the temperature of the exhaust gas at the sampling probe is above 463 K (190 °C);

For subsequent collection of the particulates, a sample of the dilute exhaust gas is passed to the particulate sampling system (section 2.4, figures 21 and 22).

"Opacimeter" means an instrument for continuous measurement of the absorption coefficients of the light by the exhaust gases emitted by vehicles.

The exhaust gas temperature must be measured at a point in the exhaust pipe(s) adjacent to the outlet flange(s) of the exhaust manifold(s).

shall be installed facing upstream at a point where the dilution air and exhaust gas are well mixed, i.e. on the dilution tunnel (DT) centreline approximately 10 tunnel diameters downstream of the point where the exhaust enters the dilution tunnel;

The analysers shall have a measuring range appropriate for the accuracy required to measure the concentrations of the exhaust gas components (section 3.1.1).

With these systems, the flow into the transfer tube is matched to the bulk exhaust flow in terms of gas velocity and/or pressure, thus requiring an undisturbed and uniform exhaust flow at the sampling probe.

The opacity of the exhaust gases produced by the engine shall be measured with the engine running under full load and at steady speed.

For each engine speed the absorption coefficient of the exhaust gases shall not exceed the limit value given in the table in Annex VI.

They are necessary for checking the exhaust split, and may be used to adjust PCV1 and PCV2 for precise split control.

Exhaust pipes passing through accommodation or wheelhouse must be enclosed in a sufficiently gastight jacket.

With these systems, a sample is taken from the bulk exhaust stream by adjusting the dilution air flow and the total dilute exhaust flow.

With these systems, a sample is taken from the bulk exhaust stream by setting the dilution air flow and the total dilute exhaust flow.

Optionally, they may be determined in the diluted exhaust gas, if a full flow dilution system is used for particulate determination.

If electronic flow compensation EFC (see Figure 20) is used, the diluted exhaust gas flow is used as command signal for FC3.

If electronic flow compensation EFC (see Figure 20) is used, the total diluted exhaust gas flow is used as command signal for FC3.

When using a full flow dilution system for exhaust gas dilution, the tailpipe shall be connected to the system.

Raw exhaust gas is transferred from the exhaust pipe EP to the dilution tunnel DT through the sampling probe SP and the transfer tube TT.

Measuring instruments for fuel consumption, air consumption, temperature of coolant and lubricant, exhaust gas pressure and intake manifold depression, exhaust gas temperature, air intake temperature, atmospheric pressure, humidity and fuel temperature shall be used, as required. These instruments shall satisfy the requirements given in table 8:

In the case of diesel engines, the exhaust gases must be examined during the test for compliance with the conditions set out in Annex VI to Directive 72/306/EEC.

Assuming a real time raw exhaust plume in the exhaust tube, each opacimeter shows a delayed and differently measured opacity trace.

The range of the exhaust gas velocity and the pressure oscillations shall be checked and adjusted according to the requirements of Annex V, section 2.2.1, EP, if applicable.

The tubes must have the same dimensions (same diameter, length, bend radius), so that the exhaust split depends on the total number of tubes.

The diluted exhaust gas flow rate shall be determined over the cycle to calculate the mass emission values of the pollutants.