Rotary-to-linear conversion for sensor assembly and method of detecting angular position of a target through multiple structures

A sensor assembly comprising:

• a first structure defining a first interior volume having a first environment with a first temperature and a first pressure;
• a second structure disposed radially outwardly of the first structure and defining a second interior volume having a second environment with a second temperature and a second pressure each lower than the first temperature and the first pressure;
• a sensor body extending through the first structure and the second structure, the sensor body having a first end and a second end, the first end disposed proximate the first environment and the second end located radially outwardly of the second structure;
• a first sealing assembly configured to operatively couple the sensor body to the second structure and to accommodate movement of the sensor body due to relative movement between the first structure and the second structure;
• an interior cavity defined by an interior wall of the sensor body;
• a linear position sensor operatively coupled to the sensor body;
• a rotary linkage assembly located within the interior cavity, the rotary linkage assembly operatively coupled to a target at a first linkage end;
• and
• a rotary-to-linear interface disposed between a second linkage end of the rotary linkage assembly and the sensor, the rotary-to-linear interface configured to convert rotational motion of the rotary linkage assembly to linear motion directly sensed by the linear position sensor.