SILAREX – Optical NDIR multi-gas sensors

Precision and high performance: With the SILAREX platform, smartGAS offers standardized multi-channel solutions


  • Measure up to three gases simultaneously with one setup

  • Cross-sensitivity is calculated on-board

  • Measure up to 3 different concentration ranges

  • Pressure compensation on board

  • Ready to use calibrated

  • NDIR technology for complex measurement tasks

SILAREX from smartGAS

Applications such as the emission measurement of several gases like CO2, CO and SO2 or the measurement of TOC (Total Organic Carbon) require multi-channel sensors. SILAREX gas sensors have been developed for this application case and enable parallel concentration measurement of up to three measuring gases or three detection ranges with one single NDIR gas sensor. The cross-sensitivities of the individual gases are compensated directly inside the SILAREX sensor, providing the user with fully prepared and corrected measuring values via Modbus ASCII / RTU for further processing. Compared to measuring with three individual sensors, the advantages are obvious: Only one sensor needs to be calibrated and maintained; varying sample preparation, different accuracies or life cycles of the sensors do not need to be considered.

Application examples

Convenience and safety through combined measurement

smartGAS offers SILAREX multi-channel sensors as well as the required accessories for design-in and operation in different versions as a standard, e.g. for emission monitoring with carbon dioxide up to 20 % by volume, nitrogen monoxide up to 2,000 ppm and sulfur dioxide up to 1,000 ppm. It is also possible to implement two-channel versions for measuring carbon dioxide and carbon monoxide with focus on industrial production plants, cogeneration plants and cement production. The SILAREX concept forms the perfect basis for challenging measuring gas combinations and customized sensor developments.


Find the right accessories for our sensors.

Heating Element

Heating Element for NDIR gas sensors improves measurement results

Case and Add-on Controller

Case for FLOWEVO & SILAREX and EVOPLUS Controller for FLOWEVO

Test gases

Inspection of sensors on-site with regard to their measurement function

Gas Pumps

The pumps for drawing the sample gas ensure a continuous gas flow through the sensor for the best measurement results.

Particulate Filters

Particulate Filters for Cleaning Sample Gases from Foreign Substances

Peltier Gas Cooler

High-quality Peltier gas cooler for drying the gas sample to a stable dew point of e.g. +5°C.

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Phone: + 49 (0) 7131 / 797553 - 0