The standardization of electrical measuring instruments

W. B. Kouwenhoven: On the fifth page of Mr. Brooks' paper, where he lists the proposed types as portable and switchboard instruments of various grades. I think that it would be advisable to add a third grade under the portable class. This third grade might be known as laboratory instruments. It should include instruments that can be used in rough, ordinary work; something better than an indicator but not a precision instrument. I feel that a sub-classification giving the type of controlling force employed in the instrument would be of value and interest to the user. The controlling forces found in common use in deflection meters are: