| Use: | Ambient air quality monitoring of metals. See 6.2.21 for use with VOCs, SVOCs, and pesticides. |
Description:
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.
Analytes:
7. Metals
Media:
| Soil/Sediment | Water | Gas/Air |
| 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. |
| Applicable To: | |||
| Screen/Identify | Characterize Concentration/Extent | Cleanup Performance | Long-Term Monitoring |
| BETTER | ADEQUATE | BETTER | BETTER |
| 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. |
Limitations:
ASTM Standards/EPA Methods:
No applicable ASTM standards or EPA methods are cited for this technology.
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