Mechanical Comparators

In mechanical comparators, the required magnification is obtained by using mechanical linkages, levers, gearing and other mechanical devices.

Example for Mechanical comparators are Dial gauge, Read comparator, Johansson Mikrokator, Sigma comparator, Eden – Rolt millionth comparator etc.

Advantages of Mechanical Comparators

  1. Mechanical comparators are usually cheaper when compared to other amplifying devices.
  2. Mechanical comparators do not require any external sources such as electricity or air and as such the variations in outside supplies do not affect the accuracy.
  3. Usually the mechanical comparators have linear scale.
  4. They are usually robust and easy to handle.

Disadvantages of Mechanical Comparators

  1. Mechanical comparators have more moving linkages, due to which the friction is more and hence the accuracy is low.
  2. Any slackness in moving parts reduces the accuracy considerably.
  3. The mechanisms used in mechanical comparators have more inertia and this may cause them to be sensitive to vibrations.
  4. Any wear, play, backlash or dimensional faults in the mechanical devices used will also be magnified.
  5. The range of these instruments is limited, because the pointer moves over a fixed scale.
  6. It is very difficult to incorporate an arrangement for adjusting the magnification.