Thermal Conductivities

For the determination of thermal conductivity of solids, liquids and compressed liquids or liquefied gases different method and setup are available:

  • Transient hot wire for liquids (atmospheric pressure, about 253 to 433 K)
  • Transient hot wire in pressure cell (stainless steel, up to 200 bar, 253 K to 473 K)

 

 

Computer Controlled Transient Hot Wire System

The applied transient hot wire technique which is fast and reliable for liquid phase measurements. The thermodynamic basis for the transient hot wire method is the ideal model of an infinitely long, vertical line source of heat emitting a constant heat flux q to the fluid and being surrounded by a temperature field (see following figure).

Transient hot wire method

In our laboratory a commercial sensor system was combined with an individually constructed high pressure cell including high pressure pump, pressure sensor and electrical or liquid thermostat.