Note: The SPECTRO.sens module is currently in its final development phase. This page serves for product introduction and demand assessment. Series production planned Q4/2026.
NEW · TDLAS Gas Measurement Module

SPECTRO.sens
Laser-Based Gas Analysis for CH₄ — ppm-accurate, low-drift, low-maintenance.

The new gas measurement module from Wi.Tec-Sensorik. Based on Tunable Diode Laser Absorption Spectroscopy (TDLAS). Designed for OEM applications where NDIR reaches its limits.

0,1 ppm
Detection Limit
± 2 ppm
Accuracy
< 5 s
T90 Response
Secure Early Access Learn the Measuring Principle
SPECTRO.sens Wastewater Treatment Deployment
Motivation

Why another measurement module? Because NDIR reaches its limits in certain applications.

NDIR optical measurement systems have been a core part of our portfolio for years and work reliably in many applications. In some areas, however, the requirements for detection limits, long-term stability and selectivity continue to rise — that is where SPECTRO.sens comes in.

! Typical Problems in NDIR Gas Analysis

  1. Cross-sensitivities to water vapour and other hydrocarbons that distort the signal.
  2. Drift due to ageing of the IR source and optical contamination — regular zero-point adjustment required.
  3. Trade-off between range and resolution: ppm measurements and vol.% measurements often require separate modules.
  4. Maintenance effort: regular calibration, purge gas, zero-point control.

✓ What SPECTRO.sens does differently

  1. No cross-sensitivities to H₂O, CO₂, N₂O or other hydrocarbons — even at 100 vol.% ethane, propane or butane.
  2. Self-referencing at every scan: zero value U₀ is measured outside the absorption line. Drift is effectively compensated.
  3. One range for everything: 0–10,000 ppm or 0–10 vol.% with constant accuracy across the entire range.
  4. Low-maintenance: zero-point adjustment only after several months, endpoint check once per year.
Features

Designed for OEM Integration. Built for Quality and Stability.

Modular design, minimal adhesives, high-quality components. Integrated into a thermostatically controlled enclosure that simplifies deployment in demanding systems.

TDLAS Measuring Principle

Tunable laser diode in the NIR range. Scanning a CH₄ absorption line with high selectivity.

High Long-Term Stability

Zero-point stability ± 2 ppm per month. No continuous zero gas required. Reference is measured automatically.

Fast Response Time

T90 < 5 s at 1 l/min. Update rate 1 Hz. Suitable for continuous monitoring and dynamic processes.

Thermostatically Controlled at 50 °C

Heating elements stabilise the optical bench. No condensation in the analysis cell. Pressure and temperature compensation integrated.

RS232 + CAN

Standardised data communication. 24 VDC ± 2.5 V supply. Gas connection 4/6 tubing. Directly integrable into existing OEM systems.

Platform for Further Gases

Following CH₄, planned: H₂O, NH₃, CO and O₂. Same hardware platform, adapted laser configuration.

Optical beam path of SPECTRO.sens with laser diode, deflection mirrors, analysis cell and radiation detector
Optical beam path of SPECTRO.sens: 1. Tunable laser diode  ·  2. Deflection mirror  ·  3. Laser beam in the analysis cell  ·  4. Deflection mirror  ·  5. Radiation detector  ·  6. Analysis cell (AC)  ·  7. Gas inlet  ·  8. Gas outlet  ·  9. Window to analysis cell
Measuring Principle

Tunable Diode Laser Spectroscopy, simply explained.

Gas concentration is determined according to Beer-Lambert’s Law. The laser scans an absorption line in the NIR band — the line itself provides the signal, the adjacent region provides the reference.

01

Tune the Laser

The tunable laser diode is scanned via the diode current across a CH₄ absorption line in the NIR band.

02

Beam through the Cell

The laser beam passes through the analysis cell twice (double optical path length 2·L) and hits the radiation detector.

03

Signal and Reference Simultaneously

Each scan measures both inside and outside the absorption line. The zero value U₀ serves as automatic reference.

04

Calculation and Compensation

Concentration is calculated from U(c), U₀, path length L and absorption coefficient α. Pressure and temperature compensation run automatically.

Application Fields

Where SPECTRO.sens excels.

Wherever NDIR reaches its limits — where high selectivity, low detection limits and long-term stability are required — SPECTRO.sens is the right choice. Complete specifications and application details are available in our whitepaper.

Biogas Plants

Continuous process monitoring of methane content in raw biogas. High selectivity against CO₂, H₂S and water vapour — typical accompanying substances in biogas.

LDAR / EU Methane Regulation

Since 2024, oil, gas and mining operators in the EU are required to conduct regular leak surveys (LDAR). SPECTRO.sens delivers the required measurement accuracy at ppm level.

Wastewater Treatment Plants

Monitoring of digester gas production, methane recovery from sewage sludge. Low-maintenance long-term measurement without regular zero-point calibration — ideal for unattended stations.

Landfills

Mandatory monitoring of landfill gas emissions at the surface and in degassing systems. Detection of diffuse methane emissions already at ppm level.

Mining & Tunnelling

Methane monitoring in underground workings and tunnels. Since 2025, flaring of mine gas is banned in the EU — precise measurement technology is mandatory.

Industrial Safety

Gas warning systems, explosion-proof applications, monitoring of utility shafts and technical rooms. Fast T90 time under 5 s for safety-critical applications.

Agriculture & Emission Monitoring

Measurement of methane emissions from slurry systems, stables and agricultural biogas processes. Growing market driven by EU emission reporting obligations.

Food & Packaging

Protective gas monitoring in MAP packaging lines, leak detection on gas pipelines in production facilities. No cross-sensitivities to water vapour or CO₂.

Full Specifications in the Whitepaper

Detailed technical data, application examples and integration guide — as a free whitepaper. Simply request Early Access and receive it as a download immediately.

Request Whitepaper
Take Action Now

Three ways to get started with SPECTRO.sens.

We want to understand demand before series production begins. Three options — depending on how far your project has advanced.

RECOMMENDED

Secure Early Access

Register without obligation and be among the first to access initial sample modules and test conditions. Includes a free whitepaper with complete specifications.

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CUSTOM

Different Specification?

You need a different specification (range, gas, interface)? Send us the details — we will assess feasibility.

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Enquiry

One Form. Three Options. Fast Response.

Tell us what you need. We will respond within two working days with an initial assessment.

OEM Focus — direct coordination with engineering and sales, no call centre.
Flexible — we are happy to consider non-standard measurement ranges or gases.
Made in Wesel — development and manufacturing in Germany.

Required fields are marked with *. We usually respond within two working days.