Planning and installing ultrasonic meters

1. Choose the location

• Accessible for reading, replacement and verification
• H2O: indoors, or outdoors in a pit or meter box (IP68)
• DELTA III: flow sensor IP68, calculator IP65, ambient temperature +5 to +65 °C
• Fit shut-off valves upstream and downstream of the meter

2. Flush the pipework before installation

In new buildings, weld spatter, swarf, sand or sealant residues are often left in the pipes after installation. Flush the pipework thoroughly before you fit the water or heat meter, as dirt and deposits in the measuring tube can affect the measurement.

• Fit a spool piece in place of the meter while flushing
• Flush until the water runs clean
• Only then fit the meter, using new gaskets

3. Installation position and straight inlet/outlet sections

The H2O can be installed in any position. The H2O and DELTA III need no straight inlet or outlet sections from DN15 to DN40; for larger sizes, follow the installation instructions. The arrow on the meter must point in the direction of flow; the DELTA III reports an incorrect flow direction as an alarm.

4. DELTA III temperature sensors

• One sensor is fitted in the flow sensor, the second in the other pipe
• Mark clearly on the schematic which pipe is flow and which is return
• Sensor cables: 1.5 m (3.0 m from DN50), up to 15 m on request. Do not shorten the cables
• Use Pt1000 where possible; do not mix sensors from different pairs

5. Calculator and cables

The DELTA III calculator is mounted on a DIN rail or with the wall adapter supplied. The cable to the flow sensor is available in lengths from 1.5 to 15 m, longer on request. This lets you place the calculator where it is easy to read, even if the sensor is hidden under insulation. The housing is sealed after commissioning.

6. Communication

M-Bus

Bus cable to the master, polarity irrelevant; add up the loads and document the secondary addresses.

RS-485

Wire as a line with 120 Ω at both ends; use each slave address only once.

LoRa

Check reception at the installation location, especially in basements and pits. Register the devices on the network (OTAA).

NB-IoT

Check the operator’s coverage at the installation location; arrange a SIM card and data contract.

7. Power supply

Battery power is standard. Optionally, the H2O can be supplied with 12 to 42 V DC or via the M-Bus, and the DELTA III with 24 V DC or via the M-Bus with backup battery. Frequent reading, especially by radio, shortens battery life.

8. Commissioning

• Bleed the system and check that the meter does not report ‘air in pipe’
• Plausibility check: read the flow rate, temperatures and Δθ during operation
• Check that the data logger or control system reads the meter
• Record the meter number, location, meter reading and address

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