| 摘要 |
PURPOSE:To achieve the improvement in measurement accuracy and preciseness by measuring the effect by fluctuations of ambient temperature and supply voltage at the switching on of power source or at each constant time interval, storing the values thereof and performing correction to the actually measured values by using the stored values. CONSTITUTION:At the time of checking, a switch 16 is connected to the resistance 14 side and an oscillation circuit 12 generates pulses tc the pulse width thereof being subjected to the effect of ambient temperature and supply voltage. When the pulses are counted with a counter circuit 20 with the period ts of an clock oscillation circuit 19 as a reference, the count value Nc corresponds to an arbitrary ambient temperature and supply voltage and is stored in a memory circuit 21 via control circuit 24. Next, the switch 16 is connected to a temperature sensing element 13 for the purpose of measurement, the temperature becomes the temperature to be measured and the pulse width of the circuit 12 has become the value corresponding thereto. When the temperature and voltage deviate from the references, the value has received the effect thereof. The count value Nm of theis time is operated and corrected by a correction circuit 22 by using the storage value Nc of the circuit 21 at the time of checking, whereby the measurement method free from the effect of fluctuations of temperature and voltage may be established. |
