WATER METER TYPE APPROVALS

Water meters have to be approved when used as base for invoicing. In Europe, the approval can be either EC approval or MID approval. Meters that are EC approved can be taken into use until 30.10.2016, aftter that all new meters must be approver according to MID, Measuring Instrument Directive.

1. Example of EC approval sign	2. Example of MID approval sign

MID - Measuring Instrument Directive 2004/22/EC

EC approved water meters (73/33/EC) will be replaced with MID approved CE-marked water meters. MID (Measuring Instrument Directive) affects all measuring instruments in the whole EU and replaces the earlier legal EC approval. Meters that are approved according to the MID can be used after 30.10.2006. All new meters that will be taken into use after 30.10.2016 must be approved according to the MID. Meters according to the EC approval can be marketed and taken into use until 30.10.2016.

In practise the MID does not change the meters but the markings on the meters will change and so will the definitions of the flow values. Qn value will be changed into Q3 value. As well will the Qmax value change into Q4 value. However, the clear sign of all requirements being fulfilled is the CE-marking.

Water Meter
An instrument designed to measure, memorise and display the volume at metering conditions of water passing through the measurement transducer.

Minimum flowrate (Q1)
The lowest flowrate at which the water meter provides indications that satisfy the requirements concerning the maximum permissible errors (MPEs.)

Transitional flowrate (Q2)
The transitional flowrate is the flowrate value occurring between the permanent and minimum flowrates, at which the flowrate range is divided into two zones, the "upper zone" and the "lower zone". Each zone has a characteristic MPE.

Permanent flowrate (Q3)
The highest flowrate at which the water meter operates in a satisfactory manner under normal conditions of use, i.e. under steady or intermittent flow conditions.

Overload flowrate (Q4)
The overload flowrate is the highest flowrate at which the meter operates in a satisfactory manner for a short period of time without deteriorating.

Example, cold water meters: accuracy class B (EC) vs. accuracy class R80 (MID)

The corresponding values , the most common sizes