Diesel engine vehicles are equipped with specialized valves including EPM valves which act as exhaust brakes by controlling back pressure into the engine, and EGR valves which reduce emissions by re-circulating exhaust gasses.

To perform end of line test on a new range of valves the manufacturer wanted to replace their existing test rigs, which used high volume air pressure to replicate engine operating conditions. This required a large air reservoir and compressor installation which was not only expensive to operate but also occupied a large area of the manufacturing site.

Traditionally the thermostats produced by the production lines were manually tested.  This involved loading 240 thermostats into one of 9 tanks which was then heated and cooled by an operator who noted the temperature at which each thermostat operated or reset. 

After investigation, the tanks were found to suffer from thermal effects which meant that different positions in the tanks were exposed to slightly different temperatures.  The system was, therefore, designed to monitor not only the states of all 240 thermostats but also 24 temperature measurements, in each tank.  It controls the heating and cooling by downloading setpoints to controllers, according to the selected recipe of ramps and dwells.