Frequently Asked Questions
Here you can find answers to the most frequently asked questions about Opsis. If you cannot find what you are looking for, please contact us.
Can the OPSIS system be upgraded in the future to measure more gases?
Yes, OPSIS systems can always be upgraded, mostly only by software upgrade, but in some cases also by additional hardware. A list of available gas compounds that can be monitored can be found here>>.
Has OPSIS got any international approvals?
Yes, OPSIS products has been tested and approved by several international bodies such as U.S. EPA, German TÜV etc. Please click here for more information.
How do snow, rain and fog affect the performance of the system?
Since the OPSIS system uses the Differential Optical Absorption technique for calculating the gas concentrations, large variations in the light intensity can be accepted without decreased performance. Naturally, there will be a lower acceptable limit for the light intensity, so in areas with heavy fog, a shorter measurement path will be recommended for maximum data coverage.
How long can an OPSIS monitoring path for ambient air quality be?
OPSIS offers a wide range of emitter, receiver and transceiver/reflector solutions, for measurement paths from 100 metres up to 5000 metres. In order to know the most suitable path length for a specific application, please contact your nearest OPSIS representative.
Is OPSIS using Laser light?
No, not in the basic DOAS (Differential Optical Absorption Spectroscopy) systems used for ambient air quality and emissions monitoring. The light source in this case is a Xenon lamp which emits a broad banded white light. However, OPSIS also provides gas monitoring systems based on tuneable diode laser technology.
What is the meaning of the word OPSIS?
OPSIS is an ancient Greek word, meaning visual strength, according to Aristotle.
Will results from an open-path method be equivalent to those from a conventional point monitoring station?
Yes, according to U.S. EPA, the OPSIS system is approved and accepted as equivalent to the reference methods (conventional point sampling analysers). But obviously, if there are significant emission sources near the monitoring stations, the path monitoring system may be affected different from the point monitoring system, depending on the strength of the source and the wind direction.