US Patent 8169223 - Ionization vacuum gauge with CNT anode

http://www.freepatentsonline.com/8169223.html

Ionization gauges are the most sensitive gauges for very low pressure. This patent from Foxconn teaches how carbon nanotube can be used as anodes in ionization gauges to reduce sensitivity to light and temperature in extreme vacuum environments. Claim 1 reads:

1. An ionization vacuum gauge, comprising:

a cathode;

an anode surrounding the cathode,

the anode is a carbon nanotube wire structure consisting of a plurality of carbon nanotubes; and

a hollow ion collector surrounding the anode.