Carbonyl Sulfide Monitors

WORLD'S MOST PRECISE COS MONITORS

Aerodyne’s trace gas monitor for carbonyl sulfide (COS or OCS) has exceptionally fast response time, high sensitivity and chemical specificity.  The measurement sensitivity is at least 5 pptv in one second and 1 to 2 pptv in one minute.  This high sensitivity and fast time response make Aerodyne’s carbonyl sulfide monitor unique.  

The figure at right demonstrates this sensitivity.  The upper trace is the COS mixing ratio in room air plotted versus time for a twelve hour period.  The Allan plot in the lower half of the figure shows the precision as a function of averaging time.  The measurement precision for a one second averaging time is 3 pptv.

The COS monitor can also be configured to detect carbon dioxide and water vapor simultaneously.  The water measurement enables the instrument to report the dry air mixing ratios of both COS and CO2 in the presence of water vapor.

Specifications:

Molecule

COS

CO2

H2O

Laser Frequency

~2050 cm-1

Precision (1 s)

5 ppt(1 s)

2 ppt (60 s)

0.1  ppm (1 s)

0.03 ppm (60 s)

10 ppm (1 s)

3 ppm (60 s)

Accuracy

2%  or 10 ppt

2% or 0.2 ppm

2% or 20 ppm

Time response

0.1 seconds with 300 liter/min pump