Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Power Monitor provides useful information

Although I initially was uncertain of this recent purchase, trial and error proved it was most useful when I left it monitoring a device for a number of days. A week provides sufficient time to capture good data. The battery backup allows one to disconnect the monitored device and, plugging the monitor into an extension cord, read out all the recorded measurements. If the battery backup would allow a subsequent readout without having to plug the unit back into an outlet, it would be even more convenient.Anyone looking for a low cost way of checking individual power usage should be satisfied with the P3 P4460.