What is the name of the basic method of checking flow metering systems that relies on comparing water depths at different locations?

• A. Comparative Depth Measurements
• B. Depth Comparison Method
• C. Bathymetric Flow Check
• D. Depth Gauge Method

Answer: (A)

The name reflects using depth readings to check flow without directly measuring velocity. By measuring water depths at multiple locations along the same channel section, you rely on the fact that, for a given cross-section and flow conditions, discharge is tied to depth through the channel’s rating curve. If the flowmeter reading matches what the depths imply from the known stage-discharge relationship, the meter is behaving. If there’s a mismatch, it suggests a calibration drift, blockage, or other issue affecting the meter. This approach is straightforward, uses simple depth measurements, and works well as a quick consistency check.

Depth-based checks like this work best when the channel cross-section and flow regime are stable, and you have a reliable depth-discharge relationship. Other names like “depth gauge” or “depth comparison” are generic or less precise, while a bathymetric check involves bottom profiling and isn’t the standard quick verification method for this purpose.