Liquid level measuring apparatus, method, and program

A liquid level measuring method comprising the steps of:

• setting, as a target, any one of ultrasonic sensors each configured to transmit and receive an ultrasonic wave, and controlling the transmission and reception of the ultrasonic wave of the target, the ultrasonic sensors being respectively set at a plurality of positions on an outer surface of a container that stores at least one of a liquid or a gas;
• detecting an intensity of the ultrasonic wave that satisfies at least 2≦N (N:
• natural number), of the ultrasonic waves that are reflected N times on an inner surface of the container;
• determining which of the liquid and the gas a reflection point on the inner surface is in contact with, on a basis of the detected intensity of the ultrasonic wave;
• determining a liquid level of the liquid on a basis of gas/liquid determination results respectively derived by the ultrasonic sensors at the plurality of positions;
• and
• generating the ultrasonic wave made of a plurality of pulse trains with a set number of continuous waves p, wherein
• each of the ultrasonic sensors is caused to transmit the ultrasonic wave made of the pulse trains, and
• an average value of respective intensities of pulses having the number of continuous waves p is calculated.

A non-transitory computer readable recording medium storing a program which causes the computer to execute:

• setting, as a target, any one of ultrasonic sensors each configured to transmit and receive an ultrasonic wave, and controlling the transmission and reception of the ultrasonic wave of the target, the ultrasonic sensors being respectively set at a plurality of positions on an outer surface of a container that stores at least one of a liquid or a gas;
• detecting an intensity of the ultrasonic wave that satisfies at least 2≦N (N:
• natural number), of the ultrasonic waves that are reflected N times on an inner surface of the container;
• determining which of the liquid and the gas a reflection point on the inner surface is in contact with, on a basis of the detected intensity of the ultrasonic wave;
• and
• determining a liquid level of the liquid on a basis of gas/liquid determination results respectively derived by the ultrasonic sensors at the plurality of positions;
• and
• generating the ultrasonic wave made of a plurality of pulse trains with a set number of continuous waves p, wherein
• each of the ultrasonic sensors is caused to transmit the ultrasonic wave made of the pulse trains, and
• average value of respective intensities of pulses having the number of continuous waves p is calculated.