Development of a new reference spectrofluorimeter

Abstract

Abstract The spectrophotometry metrology activities at the National Research Council of Canada (NRCC) are directed towards improving instrumentation and calibration procedures for the accurate measurement of material optical properties. The increasing use of fluorescent brighteners and whitening agents in the manufacture of paints, plastics, papers, and textiles has increased the demand for reference standards for the accurate colorimetry of these fluorescent materials. This pressing need has motivated the development of a reference spectrofluorimeter at the NRCC. This automated instrument incorporates both a two-monochromator reference system and a one-monochromator (polychromatic illumination) transfer system, in a compact design. The two systems share the xenon-arc light source and the analyzing monochromator and detection optics. The instrument employs all-reflective optics, large numerical aperture (f/ 4.8) grating monochromators combined with order-sorting filters and a cooled PMT detector. The present operating range is 250 to 900 nm but an extension to 1100 nm is planned. Both systems employ a 45°/0° geometry with annular illumination (±3°) over a sample area of 6 mm x 4 mm. Software development and instrument automation are well-advanced. The conceptual design of this new instrument and the results of some preliminary performance tests on the two-monochromator system will be described.