TDLAS Dew Point Moisture Analyzers for H2O

Fast Response and Stable Dew Point Measurement Unaffected by Corrosive Gases with Laser-Based Absorption Spectroscopy

TDLAS Analyzers for H2O

Tunable Diode Laser Absorption Spectroscopy

Measurement Dew Point Range:

High-Precision Type : T-1 -70 ℃DP ~ 20 ℃DP
OEM Type : N3 -40 ℃DP ~ 20 ℃DP

The TDLAS dew point & moisture analyzer for H2O rapidly measures dew points with exceptional speed in low dew point conditions.

Brochure（English）

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Measurement Principle of TDLAS Dew Point Moisture Analyzer

The TDLAS dew point moisture analyzer uses a tunable diode laser to measure light absorption, determining moisture levels based on Lambert-Beer’s law. A low-frequency triangular waveform current, superimposed with high-frequency wavelength modulation, is supplied to the diode laser, enabling continuous modulation of the incident light directed at the measurement cell.
Through this continuous modulation, the analyzer precisely captures the optimal absorption spectrum for moisture measurement. From the detected transmission signal, a phase-sensitive detector (PSD) extracts the second harmonic signal (2f signal). The amplitude (peak height) of the 2f signal is directly proportional to the moisture concentration, allowing for quantitative dew point calculation.
In addition to the advantages of non-contact and high-speed laser-based measurement, the adoption of the 2f detection method ensures highly sensitive dew point measurement, even in low dew point ranges. This method minimizes the impact of noise and interference from other gases, enabling accurate measurement even with weak optical absorption.

Service & Support

All models of TDLAS dew point moisture analyzers are developed, manufactured, calibrated, and repaired entirely in-house at Shinyei’s own laboratories. From the initial consideration phase to installation, measurement support, repairs, and calibration services, comprehensive and prompt support is provided throughout the entire process.

For calibration, standard instruments traceable to the humidity standards of the National Institute of Advanced Industrial Science and Technology (AIST), which provides humidity standards in Japan, are utilized. Each unit undergoes comparison calibration with these standard instruments during shipment and maintenance. Additionally, calibration certificates detailing the results can be issued upon request.