The handheld ultrasonic flowmeter adopts a low-voltage, multi pulse transmission circuit, which greatly improves measurement accuracy, service life, and reliability; The dual balanced signal differential transmission and reception circuit can effectively resist strong interference sources such as frequency converters, TV towers, and high-voltage lines; Built in rechargeable nickel hydrogen battery, capable of continuous operation for more than 12 hours; Optimized intelligent signal adaptive processing, users do not need any circuit adjustments.