GB/T 16896.1 is the first part of the Chinese standard for digital recorders used in high-voltage impulse tests, and it establishes the general requirements that such instruments must satisfy. A digital recorder has largely replaced the oscilloscope and the peak voltmeter in impulse testing, but its performance must be characterised if the recorded waveform is to be accepted as evidence: the sampling rate and the analogue bandwidth determine how faithfully a fast front is reproduced, the resolution and the memory depth determine the record length, and the trigger and time base must be stable enough for the waveform parameters to be measured within the tolerances required by the test technique standards. The document defines these characteristics, the methods by which each is determined, the record of the measurement that must be kept and the treatment of the uncertainty contribution of the recorder. It is applied together with the second part, which covers the use of recorders in impulse voltage tests specifically.