Guide to MCERTS - Flowcheck

1 Guide to MCERTSF lowcheck is accredited by the Environment Agency toperform MCERTS surveys on open channel flowmeters,closed pipe flowmeters and site process configuration. What is MCERTS ?The Environment Agency has established a MonitoringCertification Scheme, referred to as MCERTS , to provide aframework within which environmental measurements canbe made to its quality requirements. MCERTS covers theproduct certification of instruments, the competencycertification of personnel, the accreditation of laboratoriesand the quality of on-site inspections. On 1st April 2003 the scheme was extended to include theflow measurement of effluent into controlled waters. TheEnvironment Agency has appointed the organisation SiraEnvironmental Certification Ltd (SIRA) to operate theMCERTS scheme for the monitoring of effluent flow. ImplicationsIf flow measurement is a condition on an EnvironmentAgency discharge permit, it is now a statutory requirementfor the flow monitoring arrangements to be inspected by acertified MCERTS inspector.

2 Water Utilities must have theirflow monitoring arrangements inspected on sites wherethey discharge more than 503 MCERTS inspection needs to establish: If the point of flow measurement is representative of the total discharge from site If the flow measurement system is capable of measuringthe total daily volumetric flow to an uncertainty of better than 8% If the permit holder has an adequate quality assurance system * See Note 1If the discharge from site is derived from the summation ofmore than one flowmeter, each meter needs to besurveyed and a combined uncertainty value holders must have their flow monitoring arrangementsinspected by an MCERTS inspector on a frequency of everyfive years or following any works that may affect theperformance of the flow measurement 1 The Consent holder's quality assurance system isconsidered separately from the inspection of their flowmeasurement system. It is only when the Consent holderhas satisfied the requirements of both aspects of thescheme that an MCERTS Site Conformity InspectionCertificate will be issued.

3 Site certification will thereforerequire the services MCERTS inspector certified to inspect the site process configuration and the particular type of flow measurement device person with approval under the MCERTS scheme to audit the adequacy of the quality assurance system MCERTS inspectorsAn MCERTS inspector may be self employed or an employeeof an independent organisation; MCERTS inspectors are notemployed directly by the Environment Agency. The individual will hold a certificate on which his scope ofappointment will be stated open channel flow systems,closed pipe flow systems and site process is no fixed charge for an MCERTS operate in a commercially competitive market;costs are subject to market Ltd. Tel: 0151 336 8328 Email: FLOW MEASUREMENT AND HYDRAULIC SURVEYSM ethod of calculating the overall uncertaintyUncertainty in flow measurement is inversely proportionalto the rate of discharge; the lower the flow rate the higherthe uncertainty and vice-versa.

4 This feature is particularlypronounced on open channel flow measurement installations. On open channel flowmeters some factors vary with theflow rate uncertainty in the discharge coefficients, andsome are fixed uncertainty in zero level. There are afurther three factors that have to be considered within eachuncertainty within the gauging structure due to the standard and construction of its within the secondary device that measures level and converts it into units of in the calibration and measurement devices used to perform the surveyFlowcheck measure a gauging structure as accurately aspossible in order to minimise the uncertainty introduced byItem 3, 'Uncertainty in the calibration and measurementdevices used within the survey'. By minimising theuncertainty introduced by our measurement equipment weimprove the chance of borderline installations achieving anuncertainty of better than 8%.The survey works and corrective measures Flowcheckundertake enable us to obtain the maximum performancefrom a flow measurement device.

5 This can make thedifference between pass and fail where it is necessary tomeet the 8% uncertainty uncertainty based on diurnal flowTo obtain a figure for the overall uncertainty in the totaldaily volume discharged, a calculation can be performedbased on the diurnal flow pattern. Over a twenty four hour period the uncertainty in flow rateis calculated at fifteen minute intervals using a formulaspecific to the type of flow measurement device overall uncertainty in total daily volume is thencalculated from the results of all the fifteen Flowcheck are specialists in flow measurement, we have nocommercial links to any manufacturer or supplier; oursurveys and reports are therefore completely perform Detailed surveys of flowmeter installations MCERTS certification of both open channel and closed pipe flowmeters open channel flowmeter calibration calculations to BS3680 Calibration and commissioning of flowmeters In situ verification of flowmeters by comparison to our own metering equipment Installation and hire of temporary flow metering equipment Flowmeter service contractsContact usTo discuss your specific requirements contact Flowcheck LtdTel:0151 336 8328 Email.