A Model 450, sound-measuring meter made by H.H. Scott Inc. Maynard, Mass. USA. The 16 cm long, metal-encased meter, can make direct measurements via an internal microphone or via an external signal. It was donated along with an ElectoVoice Model 805, crystal-contact microphone with a ~5 m long cable. With this input, it was used to detect vibrations in equipment. This model of external microphone had originally been developed by ElectroVoice as a pickup for musical instruments. The sound meter required a battery having an unusual voltage of 22.5 volts. The unit also had a 115V AC input for calibration purposes. Manuals for operation both of the meter and the microphone were also supplied. The entire assembly was housed in a wooden box. The sound meter has an AECL-NRX sticker and inventory number but it is unknown where within CRNL the instrument was used.
