The use of the diode laser enables the simultaneous detection of gas impurities in bulk or special gases. This system allows a continuous gas quality monitoring in circular supply systems or at the point-of-use in the semi-conducting industry. The device has been developed to monitor humid-, oxygen- and methane traces in any matrix gases. However, this system can be adjusted to many other gases as well.

For the quantitative determination of impurities in the lower ppb-range, laser diode spectroscopy is used in the near-infrared range (NIR-LDS). This highly sensitive measurement procedure is extremely selective and has a very wide dynamic range. If several impurities are to be measured simultaneously in the lower ppb range, then a system is required which is carefully optimized in all components and which consists of laser diode spectrometers, an pre-chamber for beam guidance and a multi-reflection gas measurement cell.

Performance H2O / 1 bar

Measurement range: 0 - 100 ppm

Detection limit: 25 ppb (3σ)

Measurement resolution: 1 ppb

Exactness: 3 % of the value or 6 ppb

Performance O2 / 1 bar

Measurement range: 0 - 10000 ppm

Detection limit: 3 ppb (3σ)

Measurement resolution: 0.1 ppm

Exactness: 3 % of the value or 1 ppm

Performance CH4 / 1 bar

Measurement range: 0 - 400 ppm

Detection limit: 52 ppb (3σ)

Measurement resolution: 1 ppb

Exactness: 3 % of the value or 11 ppb

General parameters

- measuring gas: inert and - flow rate: 0.5 - 50 slm

corrosive gases - operating pressure: 0.5 - 5 bar

- volumes: approx. 1 l (higher detection limit at 5 bar)

- measuring cell: multi- - surfaces: electropolished stainless

reflection cell, 12.4 m opt. way steel

 

Advantages of TRACESCOUT

- measurement range: ppb up to %

- non-invasive measurement

- drift-free sensor calibration

- short response times

- corrosion-resistant

- modular sensor structure