The output signal of {HEAD ~ the transducer} is amplified and then processed by a data processing unit to calculate {TAIL ~ the propane gas concentration} 
The output signal of { HEAD ~ the transducer } is amplified and then processed by a data processing unit to calculate { TAIL ~ the propane gas concentration }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL