Sewage discharge measurement with what flowmeter

Sewage on the commonly used liquid flowmeter only 3 kinds: electromagnetic flowmeter, ultrasonic flowmeter, ultrasonic nullah flowmeter

Electromagnetic flowmeter measurement accuracy is the highest, the most stable performance, and maintenance-free, so sewage discharge is usually used electromagnetic flowmeter.

Ultrasonic flowmeter although easy to install, but the measurement effect is very poor, nullah accuracy is too poor