A Multisensor Portable Analyzer for Indoor Air Quality Monitoring (.doc)

One of the primary uses of the PID at hazardous waste sites is for worker protection. The air at the site is initially screened and if values above a specified level are observed, the teams are required to wear self contained breathing apparatus. Then areas are screened for high levels in the soil, surface or groundwater by measuring the concentrations a short distance above the source. At this point, a sample could be taken for analysis by a Level II method or further measurements can be made with the PID. Clearly, the latter measurements can be made more quickly.
A variety of toxic gases and oxygen can be measured by electrochemical detection. A membrane is used to separate the phase being measured (air containing a toxic gas) from the elec¬trolyte where the measurement takes place. The type of electro¬chemical techniques used include: potentiometric, amperometric, and fuel cells. The latter tech¬nique will not be discussed in this paper.