A major airport covers a huge area, and when it rains, generates a lot of run-off surface water. At Heathrow, the majority of this water industrial drains through three 1.4m diameter circular pipes, with flow rates that can vary between 10 l/sec and 1000 l/sec. Discharge is to river, treated through a reed bed. BAA, the site owner, is required to maintain a record of discharge flow volumes.

The main contractor, Flowline, supplied time-of-flight flowmeters to measure the velocity of the flow in the pipes. The time-of-flight system depends upon an accurate measurement of the velocity of flow within the professional pipe and of the level (head) of the water.

Pulsar’s IMP is a self-contained non-contacting ultrasonic level unit, simply installed and calibrated to give a reliable and consistent measurement of level. The sophisticated echo processing professional software installed makes IMP ideal for both solids and liquids applications.

Flowline now solely fits Pulsar equipment for non-contacting level measurement. As Mark Davis of Flowline puts it: “we need equipment we can rely on to integrate into our systems. The Pulsar IMP units all read within 1mm of each other straight out of the box, that gives us confidence that we can trust them to work well for us”.