Reliable metering systems Neil Macleod Metering hierarchy Transfer - - PowerPoint PPT Presentation

Reliable metering systems

Neil Macleod

Metering hierarchy

• Transfer meters to ensure an accurate

determination of SIV

• Zone or district meters to facilitate analysis of

consumption

• Customer meters for billing purposes
• Deduction meters for multiple family

developments

Transfer meters

• High accuracy metering (multiple head

ultrasonic or magflow meters) are justified for high volume transfer points

• Regular drop testing or electronic calibration is

essential

• In Durban 17 meters out of more than 80 in

total, measure more than 95% of the total

• SIV. Make use of the Pareto principle !

Zone and district meters

• Data logging at this level of measurement is

most effective for determination of minimum night flows and ILI values.

• These meters should be read on the same day

that the customer meters in the zone it supplies are read.

Customer metering 1

• We prepare positive displacement meters to

inferential meters for domestic or residential customers

• ICI customers are metered using inferential

meters primarily

• Inferential meters require strict compliance

with installation instructions to ensure accuracy

Customer metering 2

• Meter accuracy is affected by water quality,

time and the total volume of water that has passed through the meter.

• Our domestic meters remain compliant with

the Trade Metrology Act until they are about 15 years old.

• Positive displacement meters that are 20 years
• ld, under-read by 7% and it is cost effective

to change them at that point

Pre-paid or credit meters ?

• Prepaid meter installations typically cost in

excess of R1500 compared to R500 for conventional installations

• Tampering is a consideration if meter

installations are not visited regularly

• Flow limiters as a credit control mechanism

Flow limiter

Meter reading

• Monthly reading and billing based on actual

readings and not estimates is essential

• Reading rates vary from 200 reads per meter

reader per day in CBD blocks to over 700 in townships

• Technology choice is critical: minimum

features today for a hand held terminal must include; GPS, a camera, sufficient memory to store up to 1000 readings, robust and water proof construction and a 10 hour battery life

Multi-unit metering

• Bulk meter in the name of the body corporate
• Individual meters to each unit with accounts in

the name of the occupants of each unit

• A charge of R7 per reading to each customer.
• This allows each customer to become a direct

customer of the municipality and pay for the actual water used. Credit management is more targeted.

• The difference between the total consumption

and the sum of the consumption at each unit is billed to the body corporate at ICI rates

performance

• Collection rate of about 95%
• Bill 98% of urban customers on actual

readings each month

• Customers still want proof that their meter is

read each month

• Photographic record makes for unintended

efficiencies

• Aim to continually improve performance