• Gas Metering


  • Smart Metering


  • Regulating


  • Biogas Stations


  • Stations






The smart electronic themisplus index for commercial and industrial diaphragm gas meters 
(BK-G10 – G40) is capable of directly outputting cumulative volumes using an integrated volume conversion device (temperature and pressure compensation). The combination of existing options (time- and load-dependent tariffs, load profiles, communications interval control, data logging, etc.) enables the index to be adjusted to suit the needs of individual customers.

A GSM/GPRS communications module is available for the themisplus. This complies with the requirements of the Italian UNI TS 11291 standard, ensures the authenticity and integrity of the data transferred between the communications partners and also allows granting authorization to users. A secure, remotely controlled software update and the modular principle guarantee that the technology is future-proof and also that it can be adjusted to meet new challenges retrospectively at low cost if necessary.

The indexes are supplied ready-configured, thus vastly reducing installation work.



The metrological part of the index is protected under calibration law. The separate sealing of the communications module and battery nevertheless means that the module and/or battery can be replaced with the index installed without damaging the calibration seal.


Local Communication

  • Optical bi-directional IEC 62056-21 Port (DLMS/COSEM)
  • Low frequency pulse output (Umax 10 V DC, Imax 100 mA, Fmax 4 Hz , min. pulse width 125 ms)

Wide area network communication modules

  • External antenna (optional)
Data security

The themisplus index provides secure end-to-end encryption of data, using current industrial standards. This guarantees a reasonable level of data security and data protection. It is also very well protected against attempted fraud and tampering and is able to report attempted tampering to downstream entities. Remotely readable event logs therefore provide additional security.  Asymmetric certificate based encryption methods, as well as symmetric encryption standards (e.g. AES-128) for the existing communication modules are supported.

Technical data


  • Diaphragm gas meters from BK-G10 – G40
    • Permitted gases: natural gas, propane, butane (gases acc. EN 437)

Temperature and pressure compensation

  • Full functional integrated volume converter

Data logging

  • Integrated data logging function records the delivered gas volume under reference conditions in combination with the actual time.
  • The storage has a capacity for 20 weeks for hourly values.

Firmware Update

  • acc. Welmec 7.2


  • Standard: English (others on demand)

Display and navigation

  • Backlit dot matrix LCD display
  • Intuitive menu with 3 button navigation
  • Display of kWh values possible

Battery lifetime

  • Up to 15 years (depending on readout rate and duration of the communication module)


  • MID Class 1.5
  • EN1359
  • ATEX Zone 1
  • CE
  • EMC
  • R&TTE

Protection class

  • IP 65

Gas-/Environment conditions

  • Gas temperature: -10 °C to +40 °C
  • Ambient temperature: -25 °C to +55 °C
  • Storage: -30 °C to +60 °C