The function of the start-up unit is to provide a stable dose of ammonia when the SCR catalyst of the car reaches the temperature needed for NOx conversion. The start-up unit is only used until the main cartridge has reached its operating point in a warm-up phase.
 

The start-up unit is a permanent part of the vehicle and is constructed in stainless steel to endure countless years of driving. It is electrically heated and will recharge automatically with ammonia from the main cartridges while driving. The start-up unit ensures that the vehicle exhaust can meet even the strictest requirements as the ammonia dosing is possible even in cold climate conditions.