NCAR MEDUSA Flask Sampler

The Multiple Enclosure Device for Unfractionated Sampling of Air (MEDUSA) is an automated sampler that collects cryogenically dried air into 16 1.5 L glass flasks under actively controlled flow and pressure conditions. The MEDUSA system was designed to sample for laboratory measurements of O2/N2, Ar/N2, 13CO2, and C18OO, but may also be suitable for other species. An earlier version of MEDUSA flew on the UND Citation II in the COBRA-2000 and COBRA-2003 campaigns, and on the NCAR C130 during the ACME-2004 campaign. The MEDUSA system has since been repackaged to fly on the NCAR GV during the START-08 and HIPPO campaigns, and on a Brazilian Lear Jet in BARCA-2009. An integrated control and data acquisition system logs housekeeping variables (flows, temperatures, pressures, and uncalibrated CO2 concentration) every second. The nominal flow rate is 3.3 SLPM and the flask volume is 1.5 L, resulting in a 30-second quasi-integrated sample. At 250 kts or 2000 fpm, this corresponds to a horizontal resolution of 3 km and a vertical resolution of 250 m. The MEDUSA sampler consists of a pump module, a flask module, and a dewar.

Contact name: Britton Stephens, NCAR EOL/TIIMES, 303-497-1018, stephens.

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
Limitations:if liquid water anticipated, inlet must be reversed, and max alt. decreased