This is simple instrument to check similar
sensation of varying lengths. It is essentially a caliper the jaws of which
have two pointed extensions. When the caliper is closed and the extended jaws
are touched firmly on forearm of a person who has been asked to close eyes, it
gives feeling of a single point touch. Even when the jaws are slightly opened
the feeling remains the same. Only at a significant distance does the subject
realize the touch as two point. That reading is noted.
