werden kommen - RegierungsNEWS hier/ SEHR POSITIV:
Hydrogen Sensors for Hydrogen Fuel Cell Applications
Page 6
Future Development of H2 Sensors for Fuel Cells
Several factors will drive the designs for H2 sensors for fuel cells. As the portable fuel cell market increases, cost will drive the design to
less expensive, robust and reliable sensors. DCHT is one of the players in this field, with the licensing of a DOE ORNL Thick Film
Sensor. This sensor will be priced at the $10-15 range per sensing point.
This technology is deceptively simple: it uses a Wheatsone bridge architecture, with two sensor legs cladded to measure hydrogen
concentrations to the LEL without requiring expensive temperature compensation circuitry. Similar to the other Pd sensor technologies
(in utilizing the reversible resistivity changes in Pd as a way to measure H2), it differs from the RHS in terms of range, accuracy and
fabrication technique. Technical challenges in the commercialization of the sensor result from shielding the sensing element from
contamination and poisoning of the palladium surface; therefore, a deceptively simple technology still requires extensive resources to
commercialize the product. A commercially available product is expected to be released in Spring 2001.
There is also some new development work in the area of optically sensing hydrogen using optical fiber technology. DOE NREL, in a
teaming effort with DCHT and other companies, have explored the use of hydrogen-reactive, optically sensitive materials, which can be
interrogated by a fiber optic device. Several advantages occur using this approach: optical technologies are insensitive to noise; there
can be multiple measurements using one optical box; and finally, optical technology allows for a different measurement technique in
which the mapping of the H2 field can be done over long distances. Multiple sensing points with one processor is the key advantage of
this technology. This advantage could prove to be cost-competitive over more conventional sensor technologies to monitor hydrogen
levels in large bays with multiple hydrogen sources.
Conclusion
Hydrogen-sensing technologies exist currently for the emerging fuel cell market. Cost per sensing point is currently high, although as
the volumes of fuel cells increase, the sensing costs will reduce proportionally. Palladium-based sensor technologies offer a sensing
solution over the range of technical requirements that are needed for fuel cells, and by multiplexing the sensor units to a single control
panel, additional economies can be realized.
As fuel cell technologies mature with standardization of storage media and the development and incorporation of codes and standards,
sensing solutions (specific to fuel cells) will emerge, which will further reduce the cost per sensing point.
The hydrogen economy exists and will grow quickly, as society evolves away from a petroleum-based energy infrastructure. These are
exciting times for sensor and fuel cell companies that are developing this new energy technology.
www.powerpulse.net/powerpulse/archive/aa_111300a6.stm
MfG
SI ;)
NewsFlash Hebt diese Aktie bald ab? Größtes Wolfram-Portfolio der USA vor der Neubewertung!? 
