| 摘要 |
<p>PURPOSE:To reduce the heater driving voltage to the half by forming a heater element from No.1 heater element and No.2 heater element independent from each other in electrical terms. CONSTITUTION:No.4 bridging part 54 as a gas inlet, No.1 bridging part 51 having No.1 temp-measuring resistance 7 on the surface, No.2 bridging part 52 having No.1 heat emitting body 61 and No.2 heat emitting body 62, No.3 bridging part 53 having No.2 temp-measuring resistance 8, and No.5 bridging part 55 as a gas outlet are formed over a through hole 4 in a semiconductor base board 1 in the sequence as named from the upstream toward the downstream. The same voltage of approx. 1.1V is impressed between the terminals of both heat emitting bodies 61, 62. Control is performed so that the temp. difference between each of the temp-measuring resistances 7, 8 and the surrounding is kept constant, and the flow speed of the gas is measured. This enables sensing of the flow speed of a mixture gas which involves hazard of explosion, and eventual deterioration of the heat emitting bodies and temp-measuring resistances can be known by checking the balance of heat emitting bodies.</p> |
