Heat conducting measurement cell for gas analysis - uses two hot wires placed in same gas atmosphere and separately assigned to measurement and compensation system

摘要

The heat conductance measurements are made at low absolute pressures, lower than 0.1 bar. Two hot wires (1, 2) are exposed to the same test gas atmosphere. The hot wire (1) belongs to the measurement system, and the wire (2) to a compensation system. Geometry of the wires (1, 2) themselves and/or their distances to the inner wall of the measurement cell (7) are different. The ratio of heating powers of the two wires is so adjusted, that the specific heat emission from the wire surfaces is equal.