Thermal and coductivity sensing systems, devices and methods

A sensing probe comprising:

• a probe housing having a probe tip adapted for thermal and electrical coupling with an inner surface of a thermal well, the probe tip being more thermally conductive than the probe housing;
• a thermal sensor in said housing having a sensing end and a connector end, said sensing end thermally coupled to said probe tip;
• and
• at least three leads, wherein said leads transfer electrical signals from the sensing probe and are adapted to convey temperature and conductivity information.

A sensor apparatus comprising:

• a probe housing having a probe tip, the probe tip being more thermally conductive than the probe housing;
• a thermal sensor in said housing having a sensing end and a connector end, said sensing end thermally coupled to said probe tip;
• and
• at least three leads, wherein at least two of said leads are adapted to transfer electrical signals from the thermal sensor and at least one of said leads is electrically coupled with the probe tip so that said leads are able to convey temperature and conductivity information.

A method for determining temperature and electrical conductivity of a subject media in contact with a first surface of a thermal well, the thermal well having an opposing second surface shaped to form a mating relationship with a sensing probe, the sensing probe having a tip and a body, the tip being more thermally conductive than the body, said method comprising the steps of:

• thermally coupling the thermal well and the sensing probe such that temperature and conductivity of the subject media can be determined;
• transferring thermal and conductivity signals through at least 3 leads from said sensing probe;
• and
• determining temperature and conductivity using said signals.

A method for detecting air in a fluid line, said method comprising:

• electrically coupling at least two thermal wells located in a fluid line to sensing probes such that conductivity can be determined;
• transferring conductivity signals though one or more leads from each of said sensing probes to a conductivity sensor;
• determining conductivity of contents of the fluid line between each sensing probe;
• detecting a change of conductivity of contents of the fluid line between each sensing probe;
• and
• determining if said change exceeds a predetermined threshold.