Ambient Air Monitoringby ECO PHYSICS Low Level ppb and ppt measurements of: NO, NO2, NOx, NOyNOxAmines and Ammonia
Overview • NO measurement by CLD technology • NOx – Molybdenum Converter • NO2 – Photolytic Converter • NOy – Gold Converter • NOxAmines and Ammonia • Option P – Pre-Chamber Technology • PAG003 – Pure Air Generator
NO - Measurement byChemi Luminescence Detection • Detected signal from chemical reaction in CLD: • Requires:Continuous source of Ozone Light
Signal Dependencies – Detection Limit PMT Efficiency / Noise Ratio Pressure Signal Chamber Design Sample Flow Ozone Concentration Pre-Chamber
Products – Positioning 88 89 780TR Sensitivity: 75 25 10 ppt in 30 sec. Instrument:Size: 3 4 12 HUWeight: 25 32 55 kgPower: 250 320 1000 W
NOx - Measurement • Internal Molybdenum Converter
NO2 - Measurement External Photolytic Converter PLC 860
NO2 - Measurement Things to remember! • The photolytic converter is running by UV light.Keep always one spare UV lamp on stock. • A pure air generator is a must for correct calibration
NOy - Measurement NOy is the sum of: NOx, Nitric Acid, organic nitrates, inorganic nitrates but not Ammonia!
NOy - Measurement External Gold Converter Requires CO gas at 1.5 bars, 30 ml/min NOy + CO NO + COx
30 ml /min CO - In CO - valve Focon to CLD CO - Overflow NO/NOY valve Sample - Out 1500 ml /min Cal - In Converter temperature Controller 300 C Cal. valve Sample - In Goldtube Plug 300 C Glastube NOy - Measurement Gold Converter - Principle
NOy - Measurement Things to remember! • The Gold converter requires pure CO gas for operation. The Charcoal filter set PN 210.0596 should be used for the CO gas. • CO is very toxic! Good ventilation and CO alarm is recommended • A pure air generator is a must for correct calibration
NOxAmines and Ammonia - Measurement Things to remember! • Ambient, low level NOxAmines and Ammonia measurements have a very long time constant, up to several hours due to physical conditions of NH3 • A pure air generator is a must for correct calibration
Option P – Pre-Chamber Target: Reduction of external influencing factors created by chemical compounds in sample gas. Photons might be emitted by other chemical reactions as well.
Option P – Pre-Chamber • Signal from detected chemical reactions in the CLD: • Background from other chemical reactions with ozone(HxCy – Components: Hydro Carbons) • Goal: Eliminate this background “chemical zero”
Option P – Pre-Chamber How does it work? In principle very easy, but….. NO reacts with Ozone very fast. Hydro Carbons reacting slow with Ozone. This leads us to a specific reaction chamber design.
Option P – Pre-Chamber Reaction Chamber + Option P
Option P – Pre-Chamber NO chamber pre-chamber O3 PMT
Option P – Pre-Chamber Settings? - Standard Settings • Integration time: 2.0 s (per cycle) • Frequency: 4 (cycles main, 1 cycle pre-chamber) • Flush time: 2.0 s (between p and main chamber) • Filter: 5 s (average sliding filter)
Option P – Pre-Chamber Pre How does it work? Main NO signal Real NO Flush Main Main Main Main Pre each cycleone data point one measurement cycle time 2s 2s 2s 2s 2s 2s (standard setting)
Option P – Pre-Chamber Things to remember! • Option P changes the mode how the data is measured • Only one data point per integration cycle • Option P is for slow changing signals only
Pure Air Generator PAG003 • A „must“ for precise ambient monitoring • The reference for correct zero calibration • Specifications:15 lpm @ 2 bars< 10 ppt for NO, NOx, NH3, SOx and Ozone< 3ppb for CO and Hydro Carbons< -15°C Dew point
Pure Air Generator PAG003 Principle of operation with standard external compressor for higher output
Pure Air Generator PAG003 Maintenance • Interval: 10.000 hours or 2 years • Parts: Filters, absorber cartridge Designed for continuous operation! Keep in “Stand-by” mode when not in use.
Pure Air Generator PAG003 Things to remember! • No ambient monitoring without a pure air generator
CLD 89 – Low level ppt Supreme Line • Clean Air Monitoring • Atmospheric Research • NO, NOx and NOy(NOy: NOx + Nitric Acid + organic nitrates + inorganic nitrates)(not Ammonia!)
CLD 89 – Concept • Compact • Integrated system • Closing the gap from 780 TR to CLD 88 • A new CRANOX system for the future
CLD 89 - Options • Ozone generation with O2 for high alt. applications with inlet pressure regulation • Pre-chamber for high precision base line • Y – converter for NOx measurements • PLC 860 for low level NO2 • CON 765 for NOy measurements
CLD 89 – Specifications • Max. Range: 500 ppb • Detection limit: < 25 ppt • Noise at zero: < 10 ppt • Lag time: < 1 s • Rise time (t90): < 30 s • Sample flow: 0.7 l/min • Oxygen flow: 0.12 l/min (option)
New CRANOX - System Includes: Calibrator Ozone Analyser PC & Control Software Two CLD 89 NO-Channels Photolysis Converter (external) PAG Pure Air Generator
CRANOX – SThe Future Compact system incl. all options
Impressions from Jungfraujoch The Sphinx Installations in Winter The lab Meteorological cupola
Scientific Background • Nitrogen oxide measurements at rural sites in Switzerland: Bias of conventional measurement techniques, Steinbacher, M. et al; J. Geophys. Res., 112, D11307, doi:10.1029/2006 • Peroxyacetyl nitrate (PAN) concentrations in the Antarctic troposphere measured during the photochemical experiment at Neumayer (PEAN'99), H.-W. Jacobi et al; Atmospheric Environment 34 (2000) 5235-5247 • Observational evidence for the impact of the lake breeze circulation on ozone concentrations in Southern Ontario, D.R. Hastie et al; Atmospheric Environment 33 (1999) • Eddy covariance measurements of nitric oxide flux within an Amazonian rain forest, Rummel, U. et al; J. Geophys. Res., 107(D20), 8050, doi:10.1029/2001JD000520, 2002 • In-situ comparison of the NOy instruments flown in MOZAIC and SPURT, H.-W. Pätz et al; Atmos. Chem. Phys., 6, 2401–2410, 2006 • Hohenpeissenberg Photochemical Experiment (HOPE 2000): Measurements and photostationary state alculations of OH and peroxy radicals, G. M. Handisides et al; Atmos. Chem. Phys., 3, 1565–1588, 2003