Water meter engineering, from the flow in the pipe to the bill
How Metrys meters measure water, how a reading travels to Meterexo, and what calibration and testing in Dehradun are for.
What the engineering covers
Water meter engineering is the work of turning water moving through a pipe into a number that a utility can bill and a consumer can check. At Mega Worker it starts with the meter, made, calibrated and tested in Dehradun, and follows the path its reading takes: the automatic meter reading (AMR) unit in the Metrys range that sends it, and Meterexo, the meter data management (MDM) platform that receives it.
This page explains the engineering in general terms: how the main meter types measure flow, how smart water metering carries a reading from a household connection to a bill, and why calibration matters. Sizes, accuracy classes and ratings for each Metrys model are on metryswatermeter.com.
How the meters measure flow
Two meters count turns of a rotor; two measure the moving water with nothing in its path. Specifications for every family are on metryswatermeter.com.
Multi-jet meters
Water enters the measuring chamber through several jets set around an impeller, so the impeller is driven evenly from all sides. Each turn stands for a fixed volume of water, and the count is carried to the register. A common choice for household connections.
Woltmann meters
A helical rotor sits along the axis of the pipe, so water passes straight through with little change of direction. The rotor turns in step with the flow, which suits the large flows of bulk supply lines and district mains.
Ultrasonic meters
Sound pulses are sent through the water with the flow and against it, and both are timed. Sound travels faster with the flow, and the difference gives the water's velocity; the meter works out the volume from that and the size of the pipe. Nothing moves in the water path.
Electromagnetic flow meters
Water moving through a magnetic field produces a small voltage between two electrodes, in proportion to its speed: Faraday's law. The method needs a liquid that conducts electricity, which drinking water does, and it leaves the bore of the pipe clear.
How a reading reaches the bill
Smart water metering in five steps, from the household connection to a bill in Meterexo.
- The meter registers the flow The meter registers the volume of water that has passed through the household connection.
- The AMR-100 reads the count The METRYS AMR-100 unit picks up the meter's count and turns it into a short data message.
- The message goes out by radio The AMR-100 sends it over LoRaWAN radio in the 865–867 MHz band, the band India uses for LoRaWAN.
- A gateway passes it on A LoRaWAN gateway in radio range receives the message and forwards it over the network.
- Meterexo makes the bill Meterexo stores the reading against the consumer and the scheme, and uses it to produce bills and reports.
Water meter calibration and testing
Water meter calibration means passing a known volume of water through a meter at set flow rates, called flow points, and comparing that volume with what the meter registers. The metrology standards for water meters name these points Q1 to Q4, from the lowest flow the meter must measure to the highest it can take for short periods. A meter is checked across that range because its error is rarely the same at every rate.
Low flow is where revenue quietly leaks away. A cistern refilling, a dripping tap or a roof tank topping up through a float valve all run at low rates, and a meter that under-registers there delivers water that never reaches a bill. At the Dehradun factory, calibration and testing are the last two stages of production, after manufacturing and assembly.
Standards behind the work
The quality management system is certified to ISO 9001:2015, and a certificate to ISO/IEC 17025:2017, the standard for testing and calibration laboratories, has been issued. CE marking under the Measuring Instruments Directive 2014/32/EU (MID) has also been issued, with MID Modules B and D. Certificate numbers and validity are listed on the Government and utilities page.
Questions from utility engineers
Which meter families are in the Metrys range?
Multi-jet water meters, AMR multi-jet meters, bulk Woltmann meters, ultrasonic meters, electromagnetic flow meters, prepaid meters and integrated AMR meters, along with AMR units, pressure transmitters and chlorine analysers. Sizes, accuracy classes and ratings for each are on metryswatermeter.com.
How is a reading sent from the meter?
Over LoRaWAN radio. The METRYS AMR-100 unit sends readings in the 865–867 MHz band to a LoRaWAN gateway, which passes them to Meterexo. The radio approval on file is a WPC equipment type approval for the MWAMI01 radio module.
Does someone still need to visit the meter to read it?
No. Once an AMR water meter is reporting, its readings reach Meterexo by radio without a meter reader going to the house. A site visit is still needed to install a meter and to attend to it if it is damaged.
What happens at calibration and testing?
What a meter registers is compared with a known volume of water at several flow points, from low flow to high. At the Dehradun factory these are the last two stages, after manufacturing and assembly, and the factory tests 800 meters a day.
Where do I find certificates and specifications?
Certificates are listed on the Government and utilities page and published as PDFs at metryswatermeter.com/certificates. Specifications, including sizes and accuracy classes, are on metryswatermeter.com.