The ACRIM I Sensor Module

This is the sensor module design for the ACRIM I instrument. The triangles in the body of the modules are the conical sensors. The primary cavity views the sun when the shutter in front of it (not shown) is open. The secondary cavity serves as a thermal reference to the primary cavity. The primary aperture provides a precisely measured opening that defines the surface area that the incoming light hits. The measurement the sensor produces is in watts per square meter (power/area).