Patent ID: 7451644

Claim:
Method for verifying the performance of a partial-stroke-freedom-of-movement test on valve ( 3 a ), said valve ( 3 a ) controlled by an actuator ( 1 ), utilizing a drive ( 2 ), a drive element ( 3 ), an actuating element, a position controller ( 5 ), said position controller includes a first distance sensor ( 7 ), a first evaluation unit ( 8 ), a second distance sensor ( 11 ), and, a second evaluation unit ( 13 a ), comprising the following steps: moving said valve ( 3 a ) with said drive ( 2 ), said drive uses said drive element ( 3 ) to act on said valve ( 3 a ), said drive element is connected to said actuating element, said drive element capable of moving said valve ( 3 a ) an actuating distance; moving said drive element ( 3 ) including said actuating element with said position controller ( 5 ) over a portion of said actuating distance; evaluating and storing signals from said first distance sensor ( 7 ) with and in said first evaluation unit ( 8 ); detecting, independently, movement of said drive element ( 3 ) of said actuator ( 1 ) using said second distance sensor ( 11 ), said second distance sensor ( 11 ) connected to said second evaluation unit ( 13 a ); and, acquiring and recording, simultaneously, movement of said drive element ( 3 ) of said actuator ( 1 ) as sensed by said first and second distance sensors ( 7 , 11 ).