In industry where in, the velocities being measured are often those flowing in ducts and tubing where measurements by an anemometer would be difficult to obtain. In these kinds of measurements, the most practical instrument to use is the TELELIN pitot tube. The pitot tube can be inserted through a small hole in the duct with the pitot connected to a TELELIN U-tube water gauge or TELELIN Inclined tube manometer or TELELIN digital manometer or differential pressure gauge for determining the velocity inside the ducted wind tunnel. One use of this technique is to determine the amount of cooling that is being delivered to a room.
The fluid flow rate in a duct can then be estimated from:
Volume flow rate (cubic feet per minute) = duct area (square feet) × velocity (feet per minute)
Volume flow rate (cubic meters per second) = duct area (square meters) × velocity (meters per second)
The pitot tube is a simple and convenient instrument to measure the difference between static, total and dynamic pressure (or head). The head - h - (or pressure difference - dp) can be measured and calculated with u-tube, Incliend Tube manometers, electronic pressure transmitters or similar instrumentation.