| 摘要 |
PURPOSE:To obtain correct oxygen concentration and moisture, by converting limit current values by a circuit into an output voltage as obtained when voltages equal to two applied voltages in an atmospheric gas to be measured containing steam are applied to sensors to detect the concentration of steam in a proportional relationship from a difference between both voltages. CONSTITUTION:A circuit with a trimmer (variable resistor) having a function of converting a current value into a voltage value is used to perform an adjustment so as to make a difference down to zero between output voltages E1 and E2 of sensors 1 and 2 in an atmospheric gas not containing steam such as dry air, hence to E1=E2. Limit current values IL1 and IL2 as obtained when voltages equal or almost equal to applied voltages V1 and V2 in the atmospheric gas containing steam are applied to the sensors are converted with a circuit into output voltages E1 and E2. Then, a difference DELTAE is determined between the voltages E1 and E2 to detect the concentration of steam from a proportional relationship between the DELTAE and a steam partial pressure. Moisture is determined by computation by using the output voltages E1 and E2, atmospheric pressure and temperature. |
