Project Appreciation and Objectives
Commercial revenue meters account for a significant proportion of water consumption so it is important that any under-registration is understood. Whilst individual companies have carried out tests on samples of meters, there has been no concerted effort to study performance trends, as there has been for domestic meters. This project filled that gap.
Commercial meters tend to be bigger than domestic meters - 20mm upwards - and a mixture of types including single jet, turbine and electromagnetic meters, as well as the rotary piston meters used for domestic metering.
It is often assumed that the results from domestic meters can be extrapolated to small (20-40mm) commercial meters. Is this assumption valid, and on what grounds should any extrapolation be based? For larger meters, the test data that has been published shows that turbine meters behave significantly differently to rotary piston meters.
There are many practical issues when considering commercial meter under-registration including:
- availability of test data covering different meter types, sizes and ages;
- cost of obtaining such data for large meters;
- availability of consumption data required to determine volumetric under-registration from meter error curves.
With the anticipated growth of household metering likely to put pressure on a company's metering resources - particularly installers - and budgets in the next AMP period, it will be important to maximise the efficiency of commercial metering activities.
The objectives of this project were to:
- identify how the performance of the main types of commercial meter changes over time;
- develop best practice for derivation of under-registration for commercial meters;
- show how this can be used to derive cost efficient replacement strategies.
Benefits to Clients
- Improve under-registration estimates used in water balance and leakage calculations.
- Provide robust and independent data to support estimates of commercial meter under-registration.
- Minimise revenue loss.
- Enable informed planning of cost effective meter replacement policies.
- Review current commercial metering practice.
- Collate existing test data.
- Test a sample of meters.
- Develop under-registration methodology.
- Develop replacement strategies.
- Full technical report.
- Electronic source for large meter performance data.
Related WRc Work
- Long term performance of domestic water meters including CP188 (2004) and CP324 (2008).
- Non-household metering manual, 1998.
- New technology meters, CP138, 2006.
- Large meter testing for individual clients.