Powertronics PQR D50 Voltage Disturbance Recorder, Black The PQR D50 Power Quality Recorder measures, records and reports power disturbances aiding in the analysis of power quality for AC power Records the time and magnitude of disturbances such as Sags, Surges, High Frequency noise, Impulses, Dropouts, Power failures and Frequency changes Datalogger will store 32,000 of the average readings in Flash RAM Provided with the PQR D50 is the PQR Host communications Software, this software facilitates the downloading and displaying of the collected data USB/RS232 cable for connecting to either type of port