Ambient air monitoring using long path techniques
Abstract
The accuracy of two laser-based long path monitoring systems for ambient trace gases is examined. Reference signal levels must be known for accurate measurements. In a CO2 laser system closely spaced wavelengths minimize zero drift and may be sufficient to ensure accurate measurements. Field tests using a semiconductor diode laser composed of Pb-salt compounds show that accurate measurements can be obtained using a single mode, high power (about 1 mW) device with active frequency control.
- Publication:
-
In: International Conference on Environmental Sensing and Assessment
- Pub Date:
- 1976
- Bibcode:
- 1976esa.....2....1M
- Keywords:
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- Air Quality;
- Carbon Dioxide Lasers;
- Laser Applications;
- Pollution Monitoring;
- Semiconductor Lasers;
- Frequency Control;
- Infrared Lasers;
- Optical Paths;
- Retroreflection;
- Trace Elements;
- Instrumentation and Photography