TY - GEN AU - J R Lepkowski C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1973-01-01 05:01:00 DO - https://doi.org/10.6028/NBS.IR.73-253 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1973 TI - Description and performance characteristics of engineering models of visual alerting devices: ER -