TY - GEN AU - Hammond, H K AU - Mason, H L C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1971-01-01 05:01:00 DO - https://doi.org/10.6028/NBS.SP.300v7 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1971 TI - Precision measurement and calibration ::selected NBS papers on radiometry and photometry ER -