Abstract: A display system for sensing a finger of a user applied to the display system includes a display panel; a sensor for sensing the finger; a sensing light source configured to emit a first light having a first wavelength W1; and a reflective polarizer disposed between the display panel and the sensor. For a substantially normally incident light, an optical transmittance of the reflective polarizer versus wavelength for a first polarization state has a band edge such that for a first wavelength range extending from a smaller wavelength L1 to a greater wavelength L2 and including W1, where 30 nm?L2?L1?50 nm and L1 is greater than and within about 20 nm of a wavelength L3 corresponding to an optical transmittance of about 50% along the band edge, the optical transmittance has an average of greater than about 75%.

Abstract: A calibration device and a method of calibrating a mass spectrometer are described where two or more immiscible mass spectrometry calibration compounds in close proximity to each other share a common headspace volume above their liquid surfaces. This arrangement allows each calibrant to evaporate at differing rates while allowing the headspace concentrations to remain relatively unchanged over time (forming a quasi-equilibrium calibrant mixture). The mixture is either delivered to an ion source of a mass spectrometer or to a vacuum pump via a flow restrictor from a calibration vial. The calibrant gas mixture in the headspace volume may be used to calibrate a mass spectrometer.