A few videos where I have a quick look at the rest of some Brüel & Kjær test gear that I saved from the dumpster over a decade ago.
Type 2760 Power Amplifier
Primarily intended to drive a "shaker" for vibration measurement, but is general purpose and can also drive a speaker.
Type 1902 Distortion Measurement Control Unit
Receives a reference frequency signal from another piece of test gear, and produces two tones of nearby frequencies that can be used to measure several types of distortion.
Type 4416 Response Test Unit
For testing the frequency response of turntable pickups, but can also be used for tape recorders.
Type 4440 Gating System
Allows for the testing of loudspeakers without the need for an anechoic chamber.
Type 6202 Phase Delay Unit
Also for loudspeaker testing. Used with a phase meter, it compensates for the time taken for a signal to travel from the speaker to the testing microphone.