Abstract: A thermal energy measurement system is disclosed for use as a calorimeter capable of providing sample thermal energy measurements in selectable modes including isothermal and/or adiabatic modes. In some embodiments, the thermal energy system further comprises a closed-loop servo controller. In some embodiments, the thermal energy measurement system is capable of providing thermal energy measurements in semi-adiabatic and/or custom programmed modes. In some embodiments, the servo controller may be implemented as a feedback circuit whose process variable is either heat flow, sample temperature, a combination thereof, or a preprogrammed time dependence of the heat flow and/or sample temperature. The output of the servo controller may be used to drive a temperature control device such as but not limited to a thermoelectric module (TEM). Methods of thermal energy measurement are also disclosed.

Abstract: An array of sensitive pixel elements is configured to generate signals representative of sensed light that is associated with writing being done by a user, and an optical system concentrates light from a light source across a section of the array of sensitive pixel elements, the signals being useful to compute a subpixel measurement of a position of the light source.