A groove 26B is formed on the outer peripheral surface of the measuring element 26, and {TAIL ~ the forward end} of an engaging plate 28 pressed in from the bottom surface 10C of the head 10 is engaged with this groove 26B, whereby a forward limit stopper and {HEAD ~ a rearward limit stopper} for the measuring element 26 are constituted by the engaging plate 28 and the groove 26B 
A groove 26B is formed on the outer peripheral surface of the measuring element 26 , and { TAIL ~ the forward end } of an engaging plate 28 pressed in from the bottom surface 10C of the head 10 is engaged with this groove 26B , whereby a forward limit stopper and { HEAD ~ a rearward limit stopper } for the measuring element 26 are constituted by the engaging plate 28 and the groove 26B
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH