so that here the channel 60 communicates with the interior of the housing 2 where the bearing 6 is located the other end of the vent channel 60 opens into the boot 56 which is in turn is in communication with the interior of the sheath for the cable 54 the opposite end of the sheath is vented to the atmosphere at the location that is generally free of contaminants thus the interior of the housing 2 where the bearing 6 is located is vented to the atmosphere through the sensor 10 and through the cable 54 as shown in fig5 6 a modified sensor 70 is similar to the sensor 10 but lacks the vent channel 60 in its barrel 50 and head 52 it does have a flange 72 that lies over the exterior surface of the housing 2 and it contains a hole 74 that aligns with a partially threaded bore 76 in the housing 2 the bore 76 lies parallel to the oblique bore 18 and like the oblique bore 18 passes from the exterior surface to the interior surface of the housing 2 and thus communicate with the interior of the housing 2 and the bearing 6 the threads of the threaded bore 76 extend inwardly from the exterior surface that the flange 72 overlies the hole 74 in the flange 72 of the modified sensor 70 receives a cap screw 78 which threads into the bore 76 in the housing 2 and secures the sensor 70 firmly to the housing 2 the cap screw 78 in turn has a head 80 that overlies the flange.