NCAR staff granted patents for system to measure metabolic gases 
from cattle and flow control sensor system
 
by Joan Frisch
UCAR Media Relations


A patent for a novel system of measuring metabolic gases, such as 
methane, from cattle has been issued by the U. S. Patent Office to 
Patrick Zimmerman, of NCAR's Atmospheric Chemistry Division 
(ACD).   Cattle are thought to be a significant source of the greenhouse 
gas methane.  

ZimmermanÕs invention consists of a cowbell-sized, stainless steel 
canister,  attached to a cow halter.  A sample line runs from the canister 
to the animalÕs mouth.  The cow is fed a capsule that releases a volatile 
tracer gas at a known rate.  Since the tracer gas is emitted through the 
cowÕs mouth in the same way that metabolic gases are released, 
scientists can use the tracer to calculate the rate of emission.  The 
device enables scientists to monitor the emissions of cattle and other 
ruminants into the atmosphere without confining the animals in a 
stall or other artificial environment.  The present form of the 
apparatus was developed by Halvore Westberg, an NCAR affiliate 
scientist, and his colleague, Kristen Johnson, both research scientists at 
Washington State University.  A description and diagram appear in the 
February issue of Environmental Science and Technology.  

Another patent, for an energy-saving, versatile, flow control sensor 
system for use with instruments that need reliable and constant flow of 
a liquid or gas, was issued to Zimmerman and Gary Hampton (also 
with ACD).  Potential applications are for air pollution-monitoring 
equipment, ink-jet computer printers and kidney dialysis machines.  

Small and lightweight, the constant-flow, low-cost, air-sampling pump 
system saves power by regulating the amount of energy driving the 
pump, in contrast to previous designs, which siphoned energy away to 
regulate the flow of the fluid.  The system is a critical component of 
instruments that can be attached to tethered, helium-filled balloons for 
measuring trace gases above forest canopies and other vegetation, as 
well as for the other applications mentioned above.  The devices are 
currently part of several instruments used in biogenic trace gas flux 
studies at NCAR.  Information from these studies will be used by 
NCAR scientists to make more precise estimates of greenhouse and 
other trace gas emissions for fine-tuning climate-change models. 

The UCAR Foundation is pursuing licensing opportunities for both 
inventions.  For further information, contact Wayne Moore (phone:  
303-497-8563; Internet:  wmoore@ncar.ucar.edu).