| 摘要 |
PURPOSE:To ensure the detection of a liquid level in a broad temperature region, by changing the number of counting or a measuring time by the liquid temperature. CONSTITUTION:A liquid temperature is detected by a temperature detecting element 23 and converted into a digital value by an AD converter 26 through an amplifier circuit 25. The result is inputted to a counter circuit 18, which can be preset, and the counted value with respect to the liquid temperature is set. The setting is automatically performed so that the value is small when the liquid temperature is low and the value is large when the liquid temperature is high. The counting circuit 18 counts the output pulses from a pulse circuit 16. When the counted value reaches the preset value, the value is outputted to a holding circuit 19 and an output circuit 14, and warning is issued to the outside. When the liquid temperature is low and the self-heating power of the liquid level detecting element 6 is insufficient, the counting times are set in small value and the reference is changed. Therefore, the operation without errors is ensured in the broad temperature region. |
