The unburned particulate accumulation in the exhaust duct of {TAIL ~ 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 the duct 
The unburned particulate accumulation in the exhaust duct of { TAIL ~ 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 the duct
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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH