| abstract |
The invention relates to a method for determining the opening time (t -t) of an orifice (27) separating two spaces (28, 29) comprising a fluid at different pressures. According to the invention, the pressure (P) in one of said spaces is measured as a function of time (t) and the variations of a characteristic resulting from the pressure measurement are determined, said opening time being determined from said variations of said characteristic, which may be the derivative or the acceleration of the pressure. The method is particularly applicable to the control of the amount of reducing agent, such as gaseous ammonia, injected into a SCR-type catalyst system. |