Abstract: A digital display apparatus monitors changes in a measurement value, e.g., voltage or fuel load, and in response, controls the rate at which the display is updated, to prevent flicker. When changes in the measurement value are small in amplitude or resemble noise pulses, the response time of the display is slowed. However, when the changes in the measurement values are large in amplitude or appear to be noise-free, response time is quickened so that a correct value is rapidly displayed.

Abstract: A measuring device comprises not only a fluctuation-suppressing means between the input and output circuits for absorbing sudden variations in input signal but also a selection control means which can, if so desired, invalidate the fluctuation-suppressing function by the open-close operation on a switch outside the circuits so that the input signal can be transmitted directly to the output side. This reduces the time required for inspection and diagnostic testing and, if the processing functions used in common are incorporated internally, the same circuits can be used both for measurements requiring the fluctuation-suppressing function and for those not requiring it.