FRTR Field Sampling and Analysis Technologies Reference Guide

6 SAMPLE ANALYSIS TOOLS for VOCs, SVOCS, and PESTICIDES

6.2 EX-SITU ANALYSIS

6.2.3 Explosimeter

Use:

Explosimeters are used to verify flammable gas concentration in the atmosphere. Instruments can be used in the immediate environment or can draw samples from remote areas through the use of sampling lines or probes.

Description:

The instrument operates by the catalytic action of a heated filament in contact with combustible gases. The filament is heated to operating temperature by passage of an electrical current. When the gas sample contacts the heated filament, combustion on the surface raises the temperature in proportion to the quantity of combustibles in the sample. A sensor measures the change in electrical resistance due to the temperature increases. A signal is processed and displayed as the percentage of the combustible gas present to the total required to reach the lower explosive limit (LEL) and/or the percent combustible gas by volume.

Analytes:

1. Non-Halogenated VOCs

Media:

Soil/Sediment	Water	Gas/Air
Requires extraction to liquid or gas phase	Requires extraction to liquid or gas phase	BETTER

Selectivity:	Technique measures a part of the compound.
Susceptibility to Interference:	High.
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	SERVICEABLE	BETTER	SERVICEABLE

Quantitative Data Capability:	Does not produce quantitative data.
Technology Status:	Commercially available and routinely used field technology.
Certification/Verification:	Technology has not participated in CalEPA certification and/or CSCT verification program.
Relative Cost per Analysis:	Least expensive.

Limitations:

The catalytic element of the instrument has a limited life span.
Must be adjusted regularly (approximately once a month).
Gasoline vapors or compounds containing silicone in the test environment could impair the instrument.
Not designed for oxygen deficient environments (requires at least 10% oxygen).
Sample is destroyed during analysis.

ASTM Standards/EPA Methods:

No applicable ASTM standards or EPA methods are cited for this technology.

Sample Access/Collection Matrix

Sample Analysis Matrix

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