Interchangeable Dial for Demonstration Meter, Model B Subject_Geology providing a fixed sighting reference

providing a fixed sighting reference for telescope and spectrometer alignment on the optical bench

Used to demonstrate beat frequencies and sympathetic resonance

Molded black plastic replacement knob sized for the goggle sanitizer cabinet timer switch

a Faraday cage

configured to demonstrate Faraday's law and the principle behind transformer action

Interchangeable Dial for Demonstration Meter, Model B Subject_Geology providing a fixed sighting referenceUsed to reconfigure the demonstration meter as a different ammeter or voltmeter, this interchangeable dial carries an integrated shunt or voltage multiplier sealed in its laminated panel.