Profile: Huygen Corp. designs and manufactures instruments & sensors. Our brands include Viscor™, Suntracker™, Compumark II™, Photronic™. The Huygen 703D dual range digital lightmeter is a rugged industrial meter housed in an extruded aluminum case and configured for either illuminance or luminance measurements. For photometric accuracy and long term stability, photopic (human eye) color response is obtained by the combination of Viscor® glass filters and selenium Photronic® cells. Basic unfiltered Photronic® cells have a peak response near that of the human eye, 550 nm, and no response in the infrared portion of the spectrum. Our lightmeters are calibrated at multiple points to NIST standards.