Thermal conductivity sensing device, Methods for operation and uses of the Same

A method for measuring the thermal conductivity of one or more gaseous components in a flowing gaseous environment, the method including:

• exposing a surface of a first sensor to the flowing gaseous environment, for thermal contact between the first sensor and the gaseous environment;
• generating a first output relating to heat transfer between said surface of the first sensor and the gaseous environment;
• exposing a surface of a second sensor to the same flowing gaseous environment, for thermal contact between the second sensor and the gaseous environment;
• generating a second output relating to heat transfer between said surface of the second sensor and the gaseous environment;
• comparing the outputs of the first and second sensors;
• wherein the first sensor has an associated flow altering means to affect gas flow at least at part of said surface of the first sensor, to be different to gas flow at the surface of the second sensor.

A method of carrying out gas chromatography, the method including the steps:

• separating one or more gas components from a gas carrier mobile phase using a separation column;
• directing a gas flow from the outlet of the separation column to a thermal conductivity sensing device, the device having a first sensor and a second sensor for exposure to a gaseous environment, each sensor providing a surface for thermal contact with the gaseous environment, each sensor providing an output relating to heat transfer between said surface and the gaseous environment, the first sensor having an associated flow altering means to affect gas flow at least at part of said surface of the first sensor, to be different to gas flow at the surface of the second sensor;
• and
• comparing the outputs of the first and second sensors of the thermal conductivity sensing device.