US Patent 7377176 - Nanoparticle modified pressure transmitter

http://www.freepatentsonline.com/7377176.html

This patent teaches a fluid pressure transmitter that uses nanoparticles to reduce overall thermal expansion effects of fluids to improve the operating characteristics of the transmitter. Claim 1 reads:

1. A pressure transmitter for measuring a pressure of a process fluid, the pressure transmitter comprising:

a pressure sensor for sensing the pressure of the process fluid;

a hydraulic relay system for providing a communication channel between the process fluid and the pressure sensor; and a pressure sensor fill fluid in the hydraulic relay system, the pressure sensor fill fluid comprising:

a first hydraulic fluid for transmitting a change in the pressure of the process fluid to the sensor; and

a first volume of nano-particles suspended within the first hydraulic fluid for altering properties of the pressure sensor fill fluid.