Humidity Sensing Apparatus

A humidity sensing apparatus comprising:

• a housing comprising an outer section and a probe section extending from the outer section, the housing outer section adapted for attachment to a surface with the probe section extending through an opening in the surface into an inside volume defined by the surface;
• a circuit board assembly comprising a user interface section installed in the housing outer section and a sensor section attached to the user interface section and extending into the housing probe section;
• a connector for releasably establishing electrical connection to the circuit board assembly to enable operation of the circuit board assembly when installed within the housing and to enable removal of the circuit board assembly without displacement of the housing outer section or the housing probe section from the surface;
• a plurality of interchangeable and pre-calibrated humidity sensor modules, each humidity sensor module being alternatively, selectively, releasably and rigidly attachable to comprise at least part of the circuit board assembly sensor section, with the selectively attached humidity sensor module extending into the housing probe section for sensing humidity within the inside volume, thereby enabling replacement of one of the humidity sensor modules with another of the humidity sensor modules without recalibration of the humidity sensing apparatus.

An apparatus for sensing humidity through a surface, the apparatus comprising:

• a housing adapted for attachment to a surface and comprising a probe section adapted to extend through an opening into an inside volume defined by the surface;
• a circuit board assembly disposed within the housing and comprising circuitry for generating a signal responsive to a sensed level of humidity within the wall or duct;
• the circuit board assembly comprising a sensor section comprising a humidity sensor generating a sensor level signal responsive to the level of humidity and associated first signal conditioning circuitry generating a high level signal responsive to the sensor level signal;
• the circuit board assembly further comprising a user interface section rigidly attached to the sensor section and comprising second signal conditioning circuitry generating an output signal responsive to the high level signal;
• a guide positioning the circuit board assembly within the housing such that the sensor section extends into the probe section of the housing while the user interface section remains outside the probe section and allowing removal of the circuit board assembly from the housing without displacement of the probe section from the surface when a cover is removed from the housing.