PROCESS FOR CHECKING THE CONVERSION CAPABILITY OF A CATALYST

摘要

PCT No. PCT/DE94/00219 Sec. 371 Date Sep. 19, 1995 Sec. 102(e) Date Sep. 19, 1995 PCT Filed Mar. 1, 1994 PCT Pub. No. WO94/21901 PCT Pub. Date Sep. 29, 1994The invention relates, in particular, to the checking of the conversion of a precatalyzer associated with internal combustion engines. The checking being carried out during the overrunning of the motor vehicle given a sufficiently long idling phase. The following criteria being evaluated singly or in combination to determine if the catalyzer is operative. The first criteria checked is the difference between the temperature downstream and upstream of the catalyzer (FIG. 2). The second criteria checked is if the temperature downstream of the catalyzer is in a predetermined range (FIG. 3). The third criteria checked is if the temperature downstream and upstream of the catalyzer exhibits a minimum difference (FIG. 4). The fourth criteria checked is if the magnitude of the temperature gradient for the temperature upstream of the catalyzer is significantly greater than the magnitude of the temperature gradient of the temperature downstream from the catalyzer.