NOS Vintage General Radio Sound-Level Calibrator 1552-B with Original Box

General Radio Company Sound Level Meter Type 1551-C

NEW General Radio 1558-A Octave Band Noise Analyzer

Decibel Meter Recorder 13 Inches Sound Level Meter, Alarm,Unlimited Data Logging

GENERAL RADIO 1552-B SOUND LEVEL CALIBRATOR

Sound Level Meter Decibel Meter Recorder 13 Inches, Alarm,Unlimited Data Logging

GENERAL RADIO COMPANY 1551-B SOUND LEVEL METER no power supply

QUEST CA-15 PERMISSIBLE SOUND CALIBRATOR