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Advanced Instruments Inc. a business unit of Analytical Industries Inc. Management. Principals Frank S. Gregus, President Patrick J. Prindible, Vice President Mohammad Razaq, Ph.D., Vice President Background 70 years in field of oxygen analysis (Teledyne) Design
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Advanced Instruments Inc. a business unit of Analytical Industries Inc.
Management • Principals • Frank S. Gregus, President • Patrick J. Prindible, Vice President • Mohammad Razaq, Ph.D., Vice President • Background • 70 years in field of oxygen analysis (Teledyne) • Design • Manufacture • Distribution
Why Measure Oxygen ? Product quality Safety Issues Environmental Concerns Life Support
Oxygen Measurement Ranges • Engineering Units Analyzer Type Pure 100.0% Percent Air = 20.9 % = 209,000 ppm Percent 1.0 % = 10,000 ppm Percent 0.1 % = 1,000 ppm ppm, Percent 0.01% = 100 ppm ppm 10 ppm = 10,000 ppb ppm 1 ppm = 1,000 ppb ppm, ppb 0.5 ppm = 500 ppb ppm,ppb 0.01 ppm = 10 ppbppb
Applications Industrial Gas Production Chemical Process Analysis Natural Gas Transmission Transportation & Storage Metals & Steel Processing Inert gas welding Semiconductor Manufacturing Electronics Fabrication Controlled Atmospheres Glove Box Monitoring Area Monitoring Food Packaging Pharmaceutical Processing Hyperbaric Diving Environmental Vapor Recovery Stack Gas Analysis
Methods of Measuring Oxygen • Galvanic Teledyne • Fuel Cell • Open Cathode • Gas Diffusion • Coulemetric Delta F, Osaka Sanso • Zirconium Oxide Ametek, Ceramatec, • Rosemount, Servomex • Paramagnetic Rosemount, Servomex, • Siemens
Product Development • Best method also best opportunity • Service customer needs • Enhance advantages • Eliminate limitations • Broaden the application range
Advantages Galvanic Fuel Cell • Accuracy • Versatility • Inexpensive
Advantages - Accuracy • Specific to oxygen • Excellent long term stability • Linear output, one point calibration • Lack of interference
Advantages - Versatility • Adaptable configuration • Measurement ranges: ppb. ppm, percent • Compatibility with industrial gas streams • Fast response • Wide operating temperature range • Compact size(s) • Accurate at any constant pressure • No external power requirements
Advantages - Versatility • Compatible Industrial Gas Streams • Ambient air • Inert Gases • Gaseous Hydrocarbons (-enes, -anes, etc.) • Hydrogen • Helium • Mixed gases • Acid gases ( 0.5% - 100% CO2 ) • Pure Oxygen
Advantages - Versatility • Inherently intrinsically safe • Lack of interference from: • Diffusion properties of other gases • Changes in flow rates • Particulates • Moisture • Position • Vibration
Advantages - Inexpensive • Manufacturing • Sample conditioning • Air Calibration • Maintenance free
Limitations Galvanic Fuel Cell • Sensitivity below 500 ppb or 0.5 ppm • Stability at ppb oxygen levels • Slow recovery from high oxygen levels • Intolerant to sulfur compounds • Comparatively short life
Limitations - Generic • Unstable readings related to changing: • Temperature • Pressure
Sensor Principle of Operation • Sample gas flows into/over/by the sensor and diffuses through a Teflon sensing membrane. • Oxygen in the sample gas dissolves in the electrolyte and migrates to the cathode where it is reduced by electrons generated by the oxidation of the anode. • Flow of electrons from anode to cathode constitutes an electric current proportional to the partial pressure of oxygen in the sample gas.
Sensor Basic Components • Diffusion barrier ( sensing membrane) • Sensing electrode ( cathode ) • Counter electrode ( anode ) • Electrolyte ( conductor ) • Body ( housing ) • Electrical connections ( to analyzer )
Sensor Critical Characteristics • Stability and accuracy • Sensitivity • Speed of response • Recovery time ( air to 10 ppm ) • Compatibility with background gases • Operating life • Operating temperature range • Maintenance requirements
Quality Issues & Impact • Stability, sensitivity • Stability • Stability, life • Stability • Stability, sensitivity, life ( % ), • compatibility with acid gases • Stability, sensitivity, recovery • Life ( ppb, ppm, all XLT ) • Life ( ppb, ppm ) • Life ( % ) • Life • Cathode material • Electroplating • Electrical connections • Anode purity • Electrolyte composition • O2 trapped by mfg process • Electrolyte volume • Electrolyte H2O evaporation • Anode material volume • Anode consumption rate
Analyzer Principle of Operation • The sample system must present the sample gas to the sensor in a manner that enables the sensor to perform properly. • Pressure of 5-30 psig (max 100) enables a metering valve to introduce sample gas at flowrates 0.1 and 10 liters per minute. • Signal generated by the sensor is amplified, filtered for high and low frequency noise, and compensated for signal output variations caused by changes in temperature. • Sample oxygen is displayed by LED or LCD digital panel meters. • Integral circuitry provides 0-1V and 4-20mA output signals to external devices and activates four alarm relay contacts.
Analyzer Basic Components • Sensor • Sensor housing • Sample system ( integral ) • Temperature control heater system ( integral ) • Electronics - amplify, temp comp, outputs, alarms • Power supply • Enclosure • Sample conditioning system ( external )
Analyzer Critical Characteristics • Sensor compatibility with application • Stability and accuracy • Response and recovery time • Configuration • Electrical: power, signal outputs, alarms • Mechanical: sample system, enclosure • Maintenance requirements • Installation requirements
Application Issues & Solutions • Gas stream composition • O2 level: nominal, min-max • Compatible gas streams ( std. ) • CO2 and acid gases, corrosives • H2S and sulfur compounds • Sensor selection, • Sensitivity ( range ) • Sample sys. materials, • Sample conditioning, • Response time • Range: ppb, ppm , % • GPR, PSR sensor • XLT sensor, SS wetted parts, coalescing filter • XLT sensor, SS wetted parts, H2Sscrubber
Standard Sensor Application • Ambient air • Inert Gases • Gaseous Hydrocarbons (-enes, -anes, etc.) • Hydrogen • Helium • Mixed gases • Pure Oxygen
Application Issues & Solutions • Operating conditions • Temperature ( location ) • Pressure • Particulates • Dewpoint ( condensation ) • Heater system • Sample conditioning • Maintenance • Installation • Low - heater system ; High - 10 ft. metal tubing at inlet • Regulate constant, 100 psi max • Minor - filter; Laden - filter, water wash, mixer, separator, pump • Coalescing filter
Sample System Basics • General: select materials and components • that do not contaminate sample • % O2 Measurements • Tygon tubing ( copper recommended ) • SS tubing for corrosive gases • ppm O2 Measurements ( above 1 ppm FS ) • Brass ( SS tubing ), Swagelock type fittings • ppb, ppm O2 Analysis ( 500 ppb, 1 ppm FS ) • Stainless steel, Swagelock type fittings
Application Issues & Solutions • Area Classification • General purpose • Outdoor, dust, water • Corrosive atmospheres • Class 1, Div 1, Group B, C, D • Class 1, Div 2, Group B, C, D • Enclosure • 19” rack/panel, wall, 7”x 4” panel mounting; portable • NEMA 4/12 • NEMA 4X ( fiberglass, SS ) • Explosion proof ( std. flame arrestors Group C, D ) - Remote ex-proof sensor • Purge System with NEMA rated enclosure - Recommend explosion proof ( unless cost of purge gas and power is not a consideration )
Application Issues & Solutions • Outdoor Location • Electrical connections • Power requirements • Output requirements • NEMA 4/12 enclosure • Heater system • ppb, ppm required • % to enhance accuracy • Stability • Electrical configuration • Alarms, Signal Outputs
Advantages ppb, ppm Analysis • Sensor • 2.5 ppb sensitivity • 500 ppb FS • Excellent stability • Recovery < 1 hour • CO2 compatibility • 12 month warranty • No maintenance • Quality • Analyzer • Approvals: CSA/UL, CE • Fast start-up bypass • Metal sensor housing • Temperature control • Full sample system • 4 alarms • Special configurations • Cost of ownership
Advancements ppb, ppm Sensor • Quality and reliability • Proprietary manufacturing process • Eliminate potential for contamination • Fewer components of common materials • Sensitivity, stability and CO2 compatibility • Proprietary electrodes and electrolyte • Proprietary manufacturing process • Warranty and expected life • Interior design increases volume of electrolyte
Advantages % Measurements • Sensor • Excellent stability • Fast response • Longer life 3-5 years • -30C to 50C range • CO2 compatibility • 24 month warranty • No maintenance • Quality • Analyzer • Approvals: CSA/UL, CE • Sensor housing option • SS tubing • Temperature control • Full sample system • 4 alarms • Special configurations • Cost of ownership
Advancements % Sensor • Long life and extended operating range • Proprietary electrodes and electrolyte • Interior design increases volume of electrolyte • Quality and reliability • Proprietary manufacturing process • Eliminate potential for contamination • Fewer components of common materials • Stability and CO2 compatibility • Proprietary electrodes and electrolyte • Proprietary manufacturing process
Competition - Micro Fuel Cell • Specific to oxygen • Tolerant to dirty sample stream • Absolute zero, one point calibration • Excellent long term stability • Compact • Inexpensive • Limited sensitivity • Slow recovery from high oxygen levels • Inconsistent performance • Shorter life, prorated warranty • Intolerant to sulfur compounds • Advantages • Disadvantages
Competition - Open Cathode • Advantages • Disadvantages • Advantages • Sensitivity to 5 ppb oxygen • Fast response and recovery • Excellent long term stability • Absolute , one point calibration • Inexpensive • Sensitive to shock • Intolerant of particulates • Continuous electrolyte addition • Maintenance intense sample system • Intolerant to sulfur compounds
Competition - Coulemetric • High sensitivity • Longer life ( non-depleting ) • Linear output , one point calibration • Good stability • Recalibrate for diffusion rate of gases • Recalibrate for inherent drift • Flow sensitive, expensive sample system • Slow recovery from O2 upset in ON position • Requires electrolyte every 6-8 weeks • Requires clean sample stream • Sensor replacement cost $3,500 • Advantages • Disadvantages
Competition - Zirconium Oxide • Advantages • Disadvantages • Fast response and recovery • Longer life ( non-depleting ) • Interference from reducing gases H2, CO, HC • 1,110-1,470°F required to conduct ions • Drift due to stability of electrodes • Sensitive to pressure changes • Intolerant to particulates, sulfur compounds • Initial expense - sensor, furnace, electronics • Ongoing expense - reference gases, power, sample conditioning, sensor replacement
Competition - Paramagnetic • Advantages • Disadvantages • Excellent stability for 99-100% analysis • Insensitive to sulfur compounds • Lacks sensitivity below 1% oxygen • Sensitive to temperature, changes in flow, position, vibration, particulates, moisture • Drift +4% of full scale per week • Expensive complex sensor • Expensive sample conditioning required • Expensive installation and maintenance