In every country, companies that discharge effluent to air, to the sewers, to rivers or to the sea are bound by governmental controls that impose limits to the levels of pollutants they are able to expel. In England and Wales, the levels are approved through the Environment Agency (EA), and one of the parameters that must be measured to confirm the discharge levels is, of course, flow. To make sure that effluent flow is measured properly, both measurement equipment and complete discharge installations are approved through the EA’s MCERTS (Monitoring Certification Scheme) process. Although MCERTS has applied to industrial effluent discharges for many years, it is increasingly being incorporated into measurement standards in the large water and wastewater companies, measuring flow into sewage works, into storm storage and also at final discharge. Accredited MCERTS inspectors check that each discharge point and the equipment fitted meets the exacting MCERTS standards.

How is MCERTS Certification achieved?

To achieve the standard, Katronic had to undertake a three-part testing and approval process, which included a factory inspection, extensive laboratory testing, which was conducted at WRC, the UK’s leading water and wastewater research centre, and involved accuracy measurements over several days in a variety of pipe materials, across a range of pipe diameters and temperatures. Only once the KATflow 150 had passed that exacting challenge could we go on to the third stage of testing, a field test against an existing MCERTS approved meter to confirm ‘real-world’ performance.

The KATflow 150 was tested in a wastewater application on a vertical pipe in one of the major water and wastewater companies in England, and we ended up with some very interesting results. We installed and commissioned the KATflow 150 and left it running, collecting time-stamped data at 15-minute intervals, which were compared to the installed electromagnetic flowmeter. Although the ‘instantaneous’ readings matched the reference meter very closely, the Katronic meter consistently measured a lower total flow over 24 hours. We investigated and discovered that, while the Katronic meter was measuring bi-directionally, which was the valuable measurement for the site, the electromagnetic meter was only measuring in the forward direction and missing the reverse flow that was happening when flow in the pipe paused. If it had been a flow that was resulting in a cost, would have meant the operator was paying too much, the KATflow 150 would have saved them money.

MCERTS Approval for KATflow 150