Water level measurement system

A water level measurement system comprising:

• a support pipe installed in a water tank filled with a fluid to measure a water level and extending in a depth direction of the water tank,
• a support rod disposed in an inner space of the support pipe and extending in a depth direction of the water tank,
• a plurality of ultrasonic probes attached to the support rod and generating ultrasonic waves, and
• a water level calculator connected to the plurality of ultrasonic probes and calculating the water level of the water tank, wherein
• the plurality of ultrasonic probes are configured to propagate the ultrasonic waves in a horizontal direction parallel to a surface of the fluid and detect reflected waves of the ultrasonic waves reflected by an interior surface of the support pipe and propagating in the horizontal direction, and
• the water level calculator calculates the water level of the water tank by using an order of the ultrasonic probes disposed at a highest position among the plurality of ultrasonic probes that detect a signal of a reflected wave reflected from the support pipe.