UNION Instruments GmbH is a Germany based manufacturer of devices and systems in gas measurement technology with a global approach, e.g.

  • Calorimeter CWD determines the calorific characteristics of combustion gases like heating and calorific value, Wobbe index, air requirement in sewage plants or in glass and ceramic industry.
  • Multi-Gasanalyzers INCA serves for continuous determination of components in natural and bio-gases
  • Pressure and temperature measuring devices DPK / ESS serves for measurement of gas and water pressure in supply networks
  • Service, engineering and customized solutions

The company headquarters are in Karlsruhe and L�beck. In both locations, departments for development and production are active; the focus in Karlsruhe is on devices for calorimetry, in L�beck for gas analyzers.
Sales activities in many countries indicate UNION Instruments' extensive and ever increasing presence on the markets. The related services are assumed by authorized distributors - by now all over the world.

Our company is certified as follows:
  • Certificate regarding the use of a Quality Management System which conforms to the requirements of DIN EN ISO 9001:2015 applicable to Design and development, manufacturing and sales of electronical and mechanical measuring equipment.
    Download : Product Catalogue
  • EG-Certificate with regard to maintaining a quality system which fulfils the requirements of Annex VII of Council Direction 94/9/EC for Equipment and protective systems intended for use in potentially explosive atmospheres (ATEX).
    Download : Product Catalogue
  • Safety with System ("Sicher mit System") regarding the requirements of systematic and effective occupational safety in accordance with the industry-specific implementation of the NLF / ILO-OSH 2001 the professional association of wood and metal.
    Download : Product Catalogue

Modular and flexible
Our instrument engineering is built strictly modular and with special suitability for user-specific demands. The key advantage i: If demands change because of improvement or increasing plant size the modular design allows extension or modification at any time.

We measure gases
We are specialized in determining calorific value (calorimetry) and composition (analysis) of almost all gases in industries.
We offer not only flexible configurable single devices, but also perfect complete solutions (systems) to our partners. The peculiarity of this solution is the integration of diverse measurement technologies in one user-specific complete system.
The customized offer implies all steps: From advising and planning through engineering and assembly to commissioning on-site.

Present in many industrial sectors
  • Calorimeter CWD- devices are traditionally used in the steel production with furnace and coke-oven gas and in the natural gas industry where they evaluate the provided gas / energy volumes - including custody transfer measurements. By the increasing use of quite different combustion gases, more industries have developed a need for our devices over the last years, mainly biogas producers, sewage system operators and the chemical industry.
  • Our Multi-Gasanalyzers INCA-analyzers are used in the process industry, including custody transfer measurements as well. Examples are analysis of natural gas, bio-methane, liquid gas, blast furnace gas, coke oven gas, mixed gases as well as incombustible gases of all kinds.
  • Customers for devices of the ESS III system are producers and operators of supply networks for gas and water. Due to the increasing shortage of resources, the detection of leaks has become an economically more and more important task.

Calorimeter CWD

The CWD2005 device series Calorimetry, Wobbe-Index und Specific Density) comprises versions of combustion calorimeters for direct and continuous determination of gas quality from the following measurands and operands:

  • Wobbe-lndex
  • Specific density
  • Heating and combustion values
  • Combustion Air Requirement (CARI) and air requirement, with integrated gas analysis
  • Energy quantity, with expanded system EMS2005.

The Wobbe index and specific density are measured, and the heating value and combustion value are calculated from these measurements. When components for gas analysis are added to the CWD2005, the air requirement, or CARI, can also be determined from the analyzed gas composition.
The operating principle of the CWD enables all combustible gas components to be detected, which allows it to be used even for gases with rapidly changing gas composition.


INCA is a modular freely user configurable measurement device for multi-component gas analysis in the bio and natural gas industries. Thousands of INCA devices are operating in the gas industry all over the world.
The INCA concept is designed to provide a custom made analysis system for specific application using standard modules for: sample gas supply, sample gas processing, sensor control and data processing. This approach guarantees the best possible analysis results, optimized cost structure in production and operation, short delivery times and facilitates retrofitting and/or replacement of components in the future.
The INCA measurement technology is an independent technical unit in which all components like sensors, pumps, valves and more are mounted on a carrier plate and connected to the control unit via an internal device bus. The individual assembly with sensors (via sensor modules) is determined by customer�s specifically required application.
This measurement unit is � in a second step - configured as a complete device system-solution with enclosures for in- and outdoor areas or even EX-areas. It is available with or without gas cooler or measuring point switching.
The modular design concept leads to variable specifications for intended applications of the INCA devices. The devices of the series INCA1000 and INCA3000 do overlap in their application possibilities. The cost and size-related benefit is up to INCA1000 whereas the INCA3000 offers a greater variety in performance and possibilities.


  • INCA1000-Series : Modular measuring device for indoor installation without a gas cooler, max. 2 sampling points
  • INCA3000-Series : Modular measuring device for indoor installation without a gas cooler, max. 6 sampling points
  • INCA4000-Series : Modular measuring device for indoor installation with a gas cooler, max. 10 sampling points
  • INCA5000-Series : Modular measuring device for outdoor installation without a gas cooler, max. 10 sampling points
  • INCA6000-Series : Modular measuring device for outdoor installation with a gas cooler, max. 10 sampling points