Optionally {TAIL ~ a scabbard} may be tapered to prevent a pipe end from contacting or damaging {HEAD ~ the reader apparatus} 456 and, as shown in FIG 13B, stops 454 a may be provided to achieve this 
Optionally { TAIL ~ a scabbard } may be tapered to prevent a pipe end from contacting or damaging { HEAD ~ the reader apparatus } 456 and , as shown in FIG 13B , stops 454 a may be provided to achieve this
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH