Development of a system to measure pollutant concentrations in the atmosphere with infrared lasers (CO2 and CO) by photo-acoustic spectroscopy

• Grant number: 97/07445-3
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: January 01, 1998
• End date: November 30, 2001
• Field of knowledge: Physical Sciences and Mathematics - Physics - Atomic and Molecular Physics
• Principal Investigator: Edjar Martins Telles
• Grantee: Edjar Martins Telles
• Company: Unilaser Indústria e Comércio Ltda

Abstract

This project proposes to develop an apparatus capable of measuring concentrations in situ of several molecular species (pollutants) present in the atmosphere with a detection limit of 1 ppb (10-9) or less. This involves an apparatus that uses an infrared laser to excite the molecular species of interest, given that the detection of the radiation absorbed is realized using the photo-acoustic effect. Pollution of the atmosphere by motor vehicles, factories, biomass burning and other sources, produces undesirable consequences both for human health and for the environment. The first step in dimensioning the problem (and for its solution) is the precise determination of the concentration of diverse pollutants in the air, as well as their spatial and temporal distribution. To this end, initially we will use a CO2 laser to develop the spectrometer. A laser which is of considerable interest is that of CO, with which it is possible to detect various pollutants deriving from the combustion of gasoline and diesel oil. Objectives of phase 1: the design of a photo-acoustic cell for gases to carry out preliminary measurements for testing; construction of a CO2 laser operating omn80 line, between 9-11 m, with output power of 5-10 W. In phase 2: construction of a photo-acoustic spectrometer for gases using CO2 laser; development of software for the analysis of samples and development of software for analysis of samples development of a CO laser and Market research. (AU)