|Use:||Ambient air quality monitoring of metals.
See 6.2.21 for use with VOCs, SVOCs, and pesticides.
Amperometric and galvanic sensors measure an electrochemical response when the sensor comes into contact with the analyte of interest Each probe contains a sensor which is specifically sensitive to a particular gas or vapor. An internal pump draws an air sample into the analyzer. These sensors typically consist of electrodes in contact with an electrolyte-saturated insulator. Selective membranes allow the gas of interest to enter the insulator, and redox reaction on the sensing-electrode surface generates a current that is proportional to the analyte concentration. When an analyte is present, it will absorb to the thin-film sensor which undergoes a change in electrical resistance proportional to the mass of analyte absorbed onto its surface. This change is measured and converted to a vapor concentration that is displayed on the readout of the analyzer.
|Requires extraction to gas phase||Requires extraction to gas phase||BETTER|
|Selectivity:||Technique measures the contaminant directly.|
|Susceptibility to Interference:||Medium.|
|Detection Limits :||10-100 ppm (soil); 0.5-10 ppm (water).|
|Turnaround Time per Sample:||Minutes.|
|Screen/Identify||Characterize Concentration/Extent||Cleanup Performance||Long-Term Monitoring|
|Quantitative Data Capability:||Data become quantitative with additional effort.|
|Technology Status:||Commercially available technology with moderate field experience.|
|Certification/Verification:||Technology has not participated in CalEPA certification and/or CSCT verification program.|
|Relative Cost per Analysis:||Least expensive.|
ASTM Standards/EPA Methods:
No applicable ASTM standards or EPA methods are cited for this technology.
|Previous Page||Sample Access/Collection Matrix||Sample Analysis Matrix||Home||Areas of Interest||Next Page|