Abstract: A control system for a burner is disclosed which detects oxygen concentration in a room using an oxygen sensor, to thereby supply an abnormality detecting signal to at least one of an alarm and a combustion reducing device to actuate it when oxygen concentration is lowered below a predetermined set value. A first comparing device and a reference value storing device are used to cause maximum oxygen concentration detected to be stored as an oxygen concentration reference value in the storing device. A second comparing device compares the deviation between the oxygen concentration reference value and a detected oxygen concentration value with an abnormality judging reference value, to thereby generate the abnormality detecting signal when the deviation is larger than the reference value. The control system is capable of effectively detecting a low oxygen concentration condition without being affected by an ambient temperature.

Abstract: A process of forming a cylinder wall of a burning cylinder for use in a heating apparatus which comprises forming an enamel pattern on the surface of a base made of a transparent or translucent and highly heat resistant material; forming thereon a metal or metallic compound layer that is 0.1 to 0.5.mu. in thickness and high in transparency; and thereafter heating the same as a whole to enamel the pattern and the layer.