Ultrasonic Heat Meter DELTA III DN25, 260 mm, qp 3.5 m³/h, M-Bus, MID

The DELTA III DN25 from Helvatron AG is a modern ultrasonic heat meter for heating and supply systems that require higher flow capacity than smaller nominal sizes. With DN25, 260 mm installation length and qp 3.5 m³/h, this variant is a strong choice for stable and accurate heat measurement in larger residential and technical environments.

Its integrated M-Bus interface makes it suitable for centralized meter reading and energy monitoring concepts. For structured remote data acquisition, the meter can be connected to the M-Center data logger.

What makes the DELTA III DN25 stand out

Built for dependable long-term operation

The ultrasonic flow sensor provides precise measurement without relying on a conventional mechanical counting mechanism in the flow section. That supports low wear, strong long-term stability and reliable performance in everyday system operation.

MID compliant for billable heat metering

This version is MID approved, making it suitable for consumption-based billing applications. The verification fee is already included, which simplifies specification and purchasing.

Well suited for M-Bus infrastructure

The integrated M-Bus communication interface allows smooth integration into remote reading systems, building automation setups and submetering projects. Paired with the M-Center, the DELTA III DN25 becomes part of a practical and scalable monitoring solution.

Flexible installation and serviceability

The DELTA III DN25 heat meter supports both horizontal and vertical installation. Its calculator is rotatable and removable, which makes positioning, servicing and reading easier. A wall mounting adapter is included in the scope of supply.

Technical data DELTA III DN25

• Manufacturer: Helvatron AG
• Series: DELTA III
• Nominal size: DN25
• Installation length: 260 mm
• Nominal flow qp: 3.5 m³/h
• Measurement principle: Ultrasonic
• Communication: M-Bus
• Baud rate: 2400 (default)
• M-Bus secondary address: Serial number
• M-Bus primary address: 000
• Temperature sensor connection: Pt500
• Temperature sensor set: short direct immersion temperature sensors, 27.5 mm
• Temperature sensor cable length: approx. 1.5 m
• Factory cable length: 1.5 m
• Power supply: Battery 19500 mAh
• Operating pressure: 16 / 25 bar
• Material: Brass
• MID compliant: Yes
• Installation position: horizontal and vertical
• Data storage: monthly values over the full service life

Product advantages at a glance

• Ultrasonic technology for precise heat metering
• Suitable for billing-related applications
• M-Bus interface for remote readout
• Horizontal and vertical installation possible
• Low installation height
• Rotatable and removable calculator
• Wall mounting adapter included
• Long-term storage of monthly values
• MID verification fee included

Typical applications for DELTA III DN25

• Apartment blocks and residential complexes
• Technical heating distribution systems
• Commercial units
• Substations and supply circuits
• M-Bus based remote metering projects
• Energy monitoring with M-Center

FAQ for DELTA III DN25

What kind of applications is the DELTA III DN25 suitable for?

It is well suited for heating and supply systems with qp 3.5 m³/h where precise and billable heat measurement is required.

Is the heat meter MID compliant?

Yes, this version is MID compliant and can be used for billing purposes.

Which communication interface is available?

The unit includes an integrated M-Bus interface for readout and monitoring.

Can the calculator be positioned separately?

The calculator is rotatable and removable, and a wall mounting adapter is included.

How can the meter data be collected centrally?

The DELTA III DN25 can be connected via M-Bus to remote reading systems and to the M-Center for centralized data collection.