| 摘要 |
PURPOSE:To enable a lower cost with a less number of parts, a by providing a predetermined memory so as to correct the non-linearity of the resistance value of a resistance bulb vs temperature. CONSTITUTION:An oscillator 41 is so arranged to be connected to a reference resistance R and a thermistor (resistance bulb) RX with a switch. The frequency of the oscillator 41 is counted with a counter 48 and the time of counting is measured with a fundamental clock oscillator 53 and a counter 54 (time counting means) until the counts of the counter 48 as shown with an overflow circuit 52 overflow a specified value. A ROM 55 is made up of memories as predetermined to correct the non-linearity of the resistance bulb RX with respect to temperature. Then, when the reference resistance R is connected to the oscillator 41 to count 54 the oscillation frequency thereof 41 connected to the bulb RX within the time equal to the time measured with the time counting means 54, the resulting counts are controlled for correction by an output of the ROM 55 using a control means 44 and displayed 57. |
