title: Some problems in the absolute measurement of germicidal ultraviolet radiation: the use of 'pen ray' lamps as a calibration standard.
mesh_terms: D003090:Coliphages / Q000528:radiation effects*; D004864:Equipment and Supplies; D004926:Escherichia coli / Q000528:radiation effects*; D005069:Evaluation Studies as Topic; D008722:Methods; D011830:Radiation Effects; D014466:Ultraviolet Rays