Pollution under control tests for diesel vehicles are a big farce
Just bend it
Most diesel vehicles in India do not meet the smoke density limit (65 on the Hartridge scale). But that's no cause for concern for owners. It's quite easy to carry home a pollution under control certificate (pucc) in India even if your vehicle does not conform to norms.
We at the Centre for Science and Environment know full well what a farce the pollution tests are. But we had hoped the new tests that came into effect from October 1, 2004 would improve matters. The tests were definitely more stringent: the earlier tests measured only the smoke emanating from the vehicles. But the new norms stipulated measurement of the warm up temperature of the engines as well as the measurement of engine speed. Moreover, the new smoke measurement instruments are controlled by sophisticated software -- taking control away from unscrupulous pollution control operators.
Let us understand how this system works. Diesel vehicles are tested in three steps. To begin with, the engines are warmed up and only if their temperature goes above 60 c does the instrument proceed to the second stage. This is called the flushing cycle: the exhaust is cleaned and the engine's revolutions per minute (rpm) is estimated. This approximation is checked against the actual rpm and smoke levels at the third stage. The instrument is programmed in such a manner that it cannot bypass the first two steps. All this lured us into believing that the days of taking the system for a ride were finally over. After all, it was the instrument which now controlled the tests, and not the operator. But how wrong we were! The equipment did indeed control everything, but the data that has to be recorded in it was still the preserve of the operators. Let us visit a pollution control centre to understand how the system can still be bent.
Mind you, the standards require that the smoke readings should not show a linear decline. It also states that the peak smoke density values are situated within a bandwidth of 25 per cent of the arithmetic mean of these values or within a bandwidth of 0.25 k -- whichever is higher. But our deft operators can circumvent that as well.
That is a trade secret, says one of them. Helpless as I was with their genius, the only good news that came out of the tour was that the operators have not yet found a jugaad for measuring engine rpm. But given their dexterity, it's just a matter of time.
I hope I am wrong.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.