To the Editor:
—Dr. Drohocki's anxiety to justify his instrument unfortunately obscures the fundamentals of the problem.There are two basic methods of displaying the integral of a potential.
Assume a fixed time interval and note the amplitude rise (proportional to the integral) in this fixed time interval. At the end of the time interval, the amplitude is returned to zero and the process is repeated. Therefore, a larger amplitude indicates a greater integral.
Assume a fixed amplitude of integration and measure the time to reach this amplitude. When the fixed value is reached, a pulse is generated and the process is repeated. Therefore, a shorter interval between pulses indicates a greater integral.
Both methods essentially charge a condenser after rectification. Both methods discharge the condenser (Method I at fixed times and Method II after the integral has reached a fixed amplitude). Both methods have technical difficulties, but, with