Liquid level sensor, ampoule, and liquid amount detection method

摘要

A liquid level sensor 18 has sensor probes 20a to 21b, and a monitor unit 23. The monitor unit 23 has a probe potential difference detecting section 25 for detecting the output potential difference between sensor probes 20a, 20b, and the output potential difference between sensor probes 21a, 21b; and a liquid level determining section 26 for determining the level of the liquid from the result of detection. The monitor unit 23 has a bubbling detection pulse generator section 28 for detecting an occurrence of bubbling of a bubbling gas from the result of detection by the probe potential difference detecting section 25 and generating a pulse signal, and a pulse counter 29 for counting the number of pulses generated by the bubbling detection pulse generator section 28, thereby making it possible to grasp the number of bubbling periods of the bubbling gas.