It's most likely that the best known diagnostic equipment for the car is the Crypton Tuner. Although others were around at the same time such as the Sun Diagnostic Tuner, it was Crypton that became synomynous with car tuning.

The original unit came with a live oscilloscope, this was excellent for finding problems with the high voltages of the secondary ignition circuit as well as checking the primary. In the days when points and carburettors were the norm this piece of equipment was superb at its job. The ignition and fuel systems were much simpler then but they required more looking after due to wear of the various components. An hour and a half connected to the Crypton Tuner could transform the way a car would run.

As the introduction of electronics in cars took place the live oscilloscope started to be replaced with a lab scope. This has the ability to test low voltage sensors as well as the usual ignition components. As the information was converted to a digital format it also became possible for the in coming signals to be captured and saved so that they could be examined more closely. These are big units and not very portable. As electronic components become smaller most of the tests performed by the big machines can now be carried out with small hand held units. (See Fluke 98/2)

This unit usually included an emission gas analyser. The early one would only test for carbon monoxide (CO) and carbon dioxide (CO2). Later ones include Hydrocarbons (HC) and Oxygen (O2) plus Lambda (click for explanation) The very latest units have all the above and also tests for oxides of nitrogen. (NOx).