The unburned particulate accumulation in the exhaust duct of a combustion system, such as the flue lining of a stove, is monitored by a circuit which receives a temperature indicating signal from {HEAD ~ a temperature sensing device} mounted within {TAIL ~ the duct} 
The unburned particulate accumulation in the exhaust duct of a combustion system , such as the flue lining of a stove , is monitored by a circuit which receives a temperature indicating signal from { HEAD ~ a temperature sensing device } mounted within { TAIL ~ the duct }
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 OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL