SMOKE METERS
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At more than £3,000 smokemeters are not cheap so make sure you get the right one. Colin Sowman has a few pointers.
With trucks already being subjected to statutory smoke tests and diesel vehicles under 3.5 tonnes eligible in January it could be a good time to invest in a smoke meter. Although most meters meet the Vehicle Inspectorate's (VI) type approval there is still variety in the products on offer.
First you have to decide if the meter is to be used for official (annual/MOT) testing, in which case it must be VI approved. Vehicles below 3.5 tonnes are classified by the VI as group A and those over that weight as group B. And despite both groups having the same pass/fail limits, 3.7m-I turbocharged and 3.2m-1 for naturally aspirated, the meter must be VI approved for both groups individually. Some meters have the pass/fail limits programmed in to give the test result automatically; others just display the averaged reading after the required number of free accelerations and leave it to the operator to interpret. As it is already known that the pass/fail limits will be reduced, check out how this is done on any meter you think of purchasing.
Some meters require different attachments for testing cars or commercial vehicles as the exhaust pipe diameters are smaller on the light vans for example. So if you need to test both make sure your budget includes all the necessary equipment. Another consideration in this category is an engine speed pickup.
Most meters are trolley mounted although it is not necessarily essential Sun's ASA200 used by the VI in its HGV test stations is the smallest hand portable unit but it could be put down and driven over unless care is taken.
Continuous readout could prove a useful feature for a smokemeter and Crypton is already using this facility to feed into its computerised diesel diagnostic system. Other readouts such as oil temperature may also be available and could prove useful as diesel diagnostics becomes more sophisticated.
So that you can get as full a picture as possible, a list of smokemeter manufactures and importers appears below. For any manufacturer or importer we have missed please contact us so that we can keep our files up to date.