Capture high-speed, high-voltage transients with the Revolution and Vision, using the optional transient capture system. Transient capture uses 1 MHz sampling for voltage, giving a 1 microsecond sample window, and includes a +/- 5000 Volt full scale on all voltage inputs. Designed for capturing disturbances originating from lightning strikes, switch closures, and high frequency resonances, transient capture catches events missed by traditional waveform capture, or cycle-based recording.
Most power quality recorders sample the voltage and current waveforms at up to 256 samples per power line cycle. This is considered high speed sampling for traditional RMS and power measurements, and even harmonics – it’s enough speed to measure up to the 128th harmonic, in theory. That sampling rate equates to roughly 65 microseconds per sample (1/(256 x 60) = 65.1 us), or 1.4 degrees (360/256 = 1.4). The PMI Eagle and Vip recorders use this sampling rate, and with 600V RMS full-scale inputs, they have enough range to measure over +/- 1000 Volts on an instantaneous sample basis.