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EXPERIMENT NO: 1 

Measure CO, HC emission from petrol engines

on exhaust gas analysis. Theory: - 

●  Carbon monoxide can have serious health impact on humans and animals. When

involved in bonds to the blood in place of oxygen. This is carried through the

bloodstream and reduces the oxygen; particularly the heart and brain can be a serious

problem for people with a Cardiovascular Carboxy Moblin formation is reversible when

the person is longer to carbon monoxide.

●  Carbon monoxide connections are measured by a technique known as non-dispersive

infrared spectroscopy. Carbon monoxide absorbs infrared radiations at the wavelengths

near 4.7 microns

●  Infrared radiations are passed through a cell containing ambient air, causing the carbon

monoxide molecule to vibration spring, as the energy is absorbed. Infrared ensuring that

the instrument responds specifically to carbon monoxide.

●  The instrument used for the measurement of CO and HC shall be approved instrument

as given in CMVR-116 (3) and meeting the requirement specified in Part-8.

●  Measurement of idling CO and HC emissions of in use 2, 3, and 4 wheelers. Vehicle 2 has

analysis type approved as per chapter 2 of Part 8 shall be used. The tachometer to

measure engine idling speed shall be approximate variation of + 50 rpm.

●  The Electronic Calibration shall be carried out after the instrument is switched ON and

there after a maximum time period of four hours.

●  The Total record of calibration shall be maintained and if it observed during calibration

that it is shifted more than the accuracy the calibration period shall be suitably reduced.

●  Calibration is done by analyzing the result of an exhaust of a vehicle whose engines are

running.

●  It shall be ensured that the handling line and probe are for from contaminates.

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(1) air tank, (2) orifice, (3) inclined manometer, (4) data logger, (5) exhaust gas analyzer, (6) dynamometer, (7) transducer, (8)

tachometer, (9) exhaust manifold, (10) carburetor, (11) weighing device, (12) fuel container and (13) computer. 

Vehicle Performance: - 

●  It shall be checked that the road vehicle exhaust system is leakproof and that manual

choice control has been returned the rest position. It shall be checked that the gas

sample probe can be in series into the exhaust pipe to a depth at least 300 mm

●  The vehicle shall have attained normal conditions as defined in immediately prior to the

measurement.

Measurement: - 

●  Immediately preceding the measurement of the engine is to be accelerated to moderate

speed with no load maintained for at least 15 seconds. Then Return to the idle speed as

set in 3.24. While the engine idles, the sample probe shall be inserted into the exhaust

pipe to the depth not less than 300 mm.

●  After the engine speed stabilizes the reading be taken. Also the CO and HC

concentration shall be recorded with other readings.

●  If it happens where the device is incorporated in exhaust system for the dilution of the

exhaust both CO and CO2 should be measured using an instrument having facility to

measure both CO and CO2. The measured value of CO shall be taken as carbon

monoxide emission from the vehicles.

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●  Good combustion is simply put this way:

HC + O2 + N2 = H2O + CO2 + N2

In troubleshooting, always remember the combustion chemistry equation:

Fuel (hydrogen, carbon, sulphur) + Air (nitrogen, oxygen) = Carbon dioxide + water

vapour + oxygen + carbon monoxide + hydrocarbon + oxides of nitrogen + sulphur

oxides. 

HC + NOx + Still air + Sunlight = Smog. 

●  Multiple exhaust system cut tests shall be connected to the manifold arrangement

terminating in a single outlet the concentration from the multiple pipes may be used.

●  If the measurements are to be repeated the entire procedure of measurement is to be

repeated. For the purpose of PUC certification if its idling CO and HC are not within

limits than it should be discontinued and vehicle should be sent to repair/service.

Two/Four Gas Analysis: - 

●  For a Two Gas analyzer the exhaust gases are measured in CO and HC form only. The

device that can only measure CO and HC as for the vehicle exhaust CO is the harmful

gas. In Two Gas analyzer it is necessary that the vehicle is at vertical position and the

probe that measure the sample is properly placed in to its place.

●  For a Four Gas Analyzer, The instrument measures four of the contents from the vehicle.

The contents measured are HC, CO, CO2 and O2. In some analyzers there is also a facility

of measurement of NOx content from the exhaust of a vehicle.●  When testing exhaust emissions, follow the tester manufacturer’s operating

instructions. Federal and state laws set maximum limits on the amount of HC and CO in

the exhaust gas. Take the readings with the engine idling at normal temperature and

Repeat the process with engine running at 1500 rpm and 2500 rpm.

NOTE: - An exhaust analyzer can also be used to check for exhaust gas leakage into the cooling

system and Fuel or Fuel vapor leaks. 

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 FAQs: - 

What are Emission norms? 

Emission norms are prescribing CO, HC and NOx level set by the government which a

vehicle would when running on roads. All the manufacturing needs to be implement the samefor vehicle being manufactured from the date of implements. 

What are EURO norms? 

EURO norms refer to the permissible emission level from both petrol and diesel vehicles

which have been implements in ensure. However in India, the government has adopted the

EURO norms for available fuel quantity and method of testing. 

●  The norms equivalent to EURO-2 are called 2005 norms but these have not get been

specified by the Indian Government.

Overview of Emission norms in India: - 

● 

1991 – Idle CO limits for gasoline vehicle and free acceleration smoke for diesel vehicle

mass emission norms of gasoline vehicle. 

●  1992  – Mass Emission Norms for Diesel Vehicles 

●  1996  –  Revision of mass emission norms for gasoline and diesel vehicle. Fitting of

catalytic converters for the vehicles using unleaded fuels. 

●  1992 – Cold start norms introduced 

●  2000 – India 2000 norms modified IDC Bharat stage II for Delhi. 

●  2003 – Bharat stage II for major 13 cities. 

●  2005 – From April Bharat stage III norms for major 13 cities. 

● 

2010  –  Bharat Stage III emissions norms for 4 wheeled vehicle for entire country.

Whereas Bharat stage VI for major 13 cities. 

Conclusion: