18-11-2015, 04:58 PM
Your estimate of the age of your potentiometer may be teensy weensy bit (technical term) out ...
This reference: http://collectionsonline.nmsi.ac.uk/deta...?t=objects&type=browse&f=CATEGORY1&s=SCM+-+Electricity+and+Magnetism&record=919 suggests 1960 - 79!
Another webpage states "This Tinsley instrument uses an external galvanometer to indicate the null, achieved when a voltage having been standardised, is divided by the correct ratio to equal the unknown using the resistance switches on which a value can be selected to four significant figures of precision. The painstaking care with which equipment of this type was handmade is remarkable by today's standards."
It obviously wouldn't have been cheap, either!
This reference: http://collectionsonline.nmsi.ac.uk/deta...?t=objects&type=browse&f=CATEGORY1&s=SCM+-+Electricity+and+Magnetism&record=919 suggests 1960 - 79!
Another webpage states "This Tinsley instrument uses an external galvanometer to indicate the null, achieved when a voltage having been standardised, is divided by the correct ratio to equal the unknown using the resistance switches on which a value can be selected to four significant figures of precision. The painstaking care with which equipment of this type was handmade is remarkable by today's standards."
It obviously wouldn't have been cheap, either!
