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Air Monitoring. Presented By: Etech Environmental & Safety Solutions, Inc. Field Air Monitoring Instruments. Collection of “Real Time” data to aid in the decisions concerning Hazards & Risks to Public & Personnel Selection of Personal Protective Equipment Site Work Zones
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Air Monitoring Presented By: Etech Environmental & Safety Solutions, Inc.
Field Air Monitoring Instruments • Collection of “Real Time” data to aid in the decisions concerning • Hazards & Risks to Public & Personnel • Selection of Personal Protective Equipment • Site Work Zones • Effects on Environment • Mitigative Actions
Field InstrumentsDesired Characteristics • Portable & Rugged • Easy to Operate • Inherently Safe • Reliable & Useful Results
Reliable & Useful Results • Response Time • Sensitivity • Selectivity • Accuracy • Precision
Hazardous Atmospheres (NEC) • Concentration between the Lower Explosive Limit and Upper Explosive Limit (LEL – UEL) • Presence of an Ignition Source • Exothermic Reaction
Definitions • Intrinsically Safe - Designed so that parts are not exposed to explosive atmosphere or, if so, there is insufficient energy for ignition • Explosion Proof – Designed to contain an explosion and cool gases to prevent spread • Purged System – Inert gas filled system; positive pressure to prevent explosive gases or vapors from entering
Instrument Protection Criteria • Class I, Division 1, Group A,B,C, & D • Intrinsically Safe • Explosion-Proof • Purged System • Class I, Division 2, Groups A,B,C, & D • Non-Incendive • Class II, Division 1 & 2, Groups E,FD, & G • Dust-Ignition Proof
Typical Instruments Used • Oxygen Indicators • Combustible Gas Indicators • Toxic Atmosphere Monitors • Radiation Survey Meters
Oxygen Indicators • Exterior Sensor • Interior Sensor • Manual Pump • Automatic Pump • Combination Units
Oxygen Indicators (cont.) • Limitations & Precautions • Atmospheric Pressure (Altitude) • Interfering Gases • Operating Temperature
Combustible Gas Indicators • Manual vs. Automatic • Super-Sensitive Unit • Combination Units (CGI-O2)
Combustible Gas Indicators (cont.) • Limitations & Precautions • Temperature • Oxygen Requirements • Interfering Gases • Lead • Sulphur • Silicone • Hydrogen Chloride • Hydrogen Fluoride • Relative Response
Combustible Gas Indicators (cont.) Always monitor for Oxygen levels before checking for combustible gases
Toxic Atmosphere Monitors • Detector Tube Systems • Specific Agent • H2S • CO • Total Vapor Analyzers • Photoionization Detectors (PIDs) • Flameionization Detectors (FIDs)
Detector Tube Systems • Pump • Bellows • Piston • Tubes • Specific Chemicals • General Chemicals • Concentration Ranges
Detector Tube Systems (cont.) • Limitations & Precautions • Accuracy • Temperature, Humidity, Pressure • Expiration Date • Lot Numbers • Color Change Endpoint • Pump Strokes, Volume • Interferences • Reusable
Toxic Vapor AnalyzersPIDs • Uses • Analyze for a broad range of contaminants • Can be calibrated to analyze for specific chemicals • Sensitivity
Toxic Vapor AnalyzersPIDs (cont.) • Considerations • Lamp Energy & Chemical IP • Dust & Humidity • High Methane • Electromagnetic Radiation • Lamp Aging • Relative Response • High Concentrations
Toxic Vapor AnalyzersFIDs • Uses • Accuracy to specific hydrocarbons • Data is usually very accurate
Toxic Vapor AnalyzersFIDs (cont.) • Considerations • Detects only organics • Sensitive to methane • Relative response • Hydrogen gas needed • Electromagnetic Radiation
Toxic Vapor AnalyzersChemical Specific • Uses • Good for personal monitors in known atmospheres • Accuracy
Toxic Vapor AnalyzersChemical Specific (cont.) • Considerations • Sensor Wear • Dust & Humidity • Unknowns • Calibration • Electromagnetic Radiation