1 / 5

NCAR Airborne Oxygen Instrument (AO2)

NCAR Airborne Oxygen Instrument (AO2). measures O 2 concentration (reported as O 2 /N 2 ratio) using a vacuum-ultraviolet absorption technique

derry
Download Presentation

NCAR Airborne Oxygen Instrument (AO2)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. NCAR Airborne Oxygen Instrument (AO2) • measures O2 concentration (reported as O2/N2 ratio) using a vacuum-ultraviolet absorption technique • based on earlier shipboard and laboratory instruments, but designed specifically for airborne use to minimize motion and thermal sensitivity and with a pressure and flow controlled inlet system • flew on the Wyoming King-Air during ACME-2007 • switches between sample gas and air from a high-pressure reference cylinder every 2 seconds and has a precision of +/- 5 per meg on a 5-second measurement • consists of a pump module, a cylinder module, an instrument module, and a dewar

  2. NCAR Airborne Oxygen Instrument (AO2) Contact name : Britton Stephens, NCAR EOL/TIIMES, 303-497-1018, stephens@ucar.eduDimensions : 19" rack wide X 30" tall X 22" deep plus a 6" diameter X 14" tall dewar Instrument weight : 200 lbs. Power: 110 AC Hazmat : 4 kg of solid CO2 (dry ice) Inlet(s) : dedicated aft facing 1/4" inlet, unheated stainless steel or Synflex secondary inlet to rule out fractionation Number of operators : 1 (eventually planned for 0 as instrument matures) Altitude requirements : max. alt 60,000 feet Ground requirements : 30 minute preflight [Stephens, B.B., R.F. Keeling, and W.J. Paplawsky, Shipboard measurements of atmospheric oxygen using a vacuum-ultraviolet absorption technique, Tellus Series B, 55, 857-878, 2003.]

  3. NCAR MEDUSA Flask Sampler • collects cryogenically dried air into 16 1.5 L glass flasks under actively controlled flow and pressure conditions • designed to sample for laboratory measurements of O2/N2, Ar/N2, 13CO2, and C18OO • earlier version flew on the UND Citation II (COBRA-2000 and 2003) and on the NCAR C130 (IDEAS, ACME-2004) • integrated control and data acquisition system logs housekeeping variables every second • consists of a pump module, a flask module, and a dewar

  4. NCAR MEDUSA Flask Sampler Contact name : Britton Stephens, NCAR EOL/TIIMES, 303-497-1018, stephens@ucar.edu Dimensions : 19" rack wide X 27 " high X 18 " deep, plus a 6" diameter X 14" high dewar Weight : 100 lbs. Power : 28 VDC Hazmat : 4 kg of solid CO2 (dry ice) Inlet : dedicated forward facing 3/8" inlet, unheated stainless steel or Synflex Number of operators : 1 (can be shared) Altitude requirements : max. alt 52,000 feet Ground requirements : 30 minute preflight COBRA-NA 2003 [Graven et al., Causes of Observed Summertime Variability in Tropospheric O2/N2 above North America, manuscript in preparation, 2008]

  5. NCAR MEDUSA Flask Sampler • nominal flow rate is 3.3 SLPM and the flask volume is 1.5 L, resulting in a 30-second quasi-integrated sample. • GV cabin throughflow ~ 24,000 SLPM (unofficial value fromGulfstream) • Flask rupture would lead to an addition of < 3 SLPM of air into cabin (~ + 0.01 % change) • Flask rupture combined with upstream flow-controller failure to full-closed and downstream flow-controller failure to full-open would lead to a removal of < 4 SLPM of air from cabin (~ - 0.015%)

More Related