TY - RPRT TI - Spectrophotometric and colorimetric analysis of seventeen glass filters duplicating the relocated and respaced union color scale for lubricating oil and petrolatum for ASTM Committee D-2 Research Division IX submitted by Hellige, Inc. AU - Schleter, John C PY - 1955 PB - National Bureau of Standards CY - Gaithersburg, MD SN - NBS report ; 4295 DO - 10.6028/NBS.RPT.4295 ER -