A Cavity Attenuated Phase Shift (CAPS) spectrometer enables scientists to quantify the extinction of light due to aerosols in the atmosphere for the purpose of measuring air pollution. This instrument enables scientists to have a quick way of measuring the atmosphere. Currently, our customer, National Oceanic and Atmospheric Administration (NOAA), is using almost all of the processing power of a laptop in order to extract the desired extinction data. Since NOAA desires an ideal data collection method, our team shall implement an all-in-one solution by use of a printed circuit board for data collection and processing in place of the laptop.
Scientific data regarding the chemical makeup of the atmosphere and its interaction with sunlight is in high demand due to its role in climate research. The primary user of the instrument will be scientists involved in aerosol and photochemistry experimentation. The secondary user of the instrument will be the earth sciences community at large. These users will benefit from the instrument by drawing upon the data it collects. The data should then be manipulated by customers software as they see fit.
Methods
This instrument will pioneer the combined use of open path cavity design with CAPS spectrometry. Previously, open path cavity design and CAPS spectrometry have not been combined in a single instrument. The overall goal is to quantify the density of aerosols present inside the cavity. For example, air samples can be placed inside the cavity and the instrument would be able to quantify the amount of carbon monoxide inside the cavity. CAPS spectrometry performs this task by measuring the rate of decay of light intensity inside the optical cavity. The rate of decay is directly proportional to the concentration of particles inside the cavity. The decay rate of the light is determined by measuring the phase shift between the input and output signals. This phase shift method gives NOAA a more efficient alternative for quantifying the extinction of light. The instrument is capable of logging captured data to a SD card for the purpose of analyzing the data on a computer.