Tech Note 320 Detail

Millikan Apparatus has an apparently inactive source.

Affected Products:

AP-8210 Millikan Oil Drop Apparatus

Problem/Symptom:
The Millikan Oil Drop Apparatus has an apparently inactive source. How may I repair this?

PASCO Solution:

Certain Millikan Oil Drop Apparatuses (MODAs) had source assemblies that were milled backwards so that OFF = ON and ON = OFF. Alternatively, the thorium activity may be below specification; we specify thorium 232 with an activity of 0.00185 microCurie. In either case, please contact us and we will send you a replacement thorium source assembly (part # 003-06169). Replacing the assembly is simple:

  1. Remove the two recessed 3/32" allen bolts from the bottom of the MODA.
  2. Remove the back plate of the light source.
  3. Loosen the lug bolt holding the white wire.
  4. Being careful not to break the electrical contact, pull the brass plate assembly partially from the base of the AP-8210.
  5. Slide out the old thorium source assembly and replace.

Creation Date: 04/17/2002
Last Modified: 04/17/2002
Mod Summary: