If the estimated capture velocity at the point of contaminant release is less then 50 fpm, the slot velocity must be increased. With the data gathered above in accordance with the procedure outlined in 3.3 Performance Testing, the slot velocity required to give 50 fpm capture velocity at the point of contaminant generation can be calculated and the system adjusted accordingly. With the required slot velocity known for each individual slot hood, future checks of the slot hood would only have to measure the average slot velocity to determine that it meets the minimum slot velocity set in the original evaluation. This assumes that there have been no changes in the system or the area since the original evaluation