"United States. Army" . . . . . . . . . . . . "Calibration procedure for dual channel recorder RO-460V1/U Hewlett-Packard model 7702B and oscillographic recorder Hewlett-Packard model 7418A0 ... preamplifier plug-in units Hewlett-Packard models 8801A, 8802A, 8805A, and 8808A"@en . . .