AB Surveying and Development also offers Flow Observation to its clients by using Mainstream AV Flowmeter. The instrument is capable of data gathering at either open (ex. culverts, creeks) or closed (ex. box or round pipes) channels. The instrument is also capable of observing the flow in the channels even if the flow is only partial.

 

This instrument is capable of measuring the flow velocity, which is the speed of the flow, by immersing the flowmeter in the liquid. The instrument has a probe that emits ultrasound into the liquid. Bubbles and solid particles then reflects back the ultrasound to the probe which is being used by the instrument to measure the speed of the flow. It is also capable of measuring the cross-sectional area of the flow at different times by installing the description of the channel and checking the level, or height, of the flow using a pressure transmitter or ultrasonic sensor. Lastly, it collects the flow rate, which is the volume of flow in the channel at a certain time, by multiplying the flow velocity to the cross-sectional area of the flow.