Watts up? measures the voltage and current thousands of times a second so it has an incredibly fast response time which enables you to "see the surge" of power when appliances are first turned on. The peak value display captures this surge so it is displayed even if it happens too fast to see live. The minimum voltage display shows the line quality and voltage dips. Minimum current and minimum watts can be used to monitor variances in appliances that run continuously. Watts up? measures true RMS power (including power factor). True RMS power is what utilities charge for, which can be different than a simple voltage and current measurement (this is called "apparent power"). The duty cycle display shows the percent of time a load is above a preset threshold level. For instance, this threshold can be set to 100 watts and with a refrigerator the duty cycle display will show the percent of time that the compressor is running. A high reading may indicate a bad motor or low freon.

Values displayed:

• Cost, in dollars and cents
• True RMS power
• Cumulative power (kwh)
• Time
• Voltage
• Current
• Average monthly cost
• Average monthly kwh
• Maximum voltage
• Maximum current
• Maximum wattage
• Power cycle (PRO)
• Power factor
• Minimum voltage
• Minimum current
• Minimum wattage
• Duty cycle

Features:

• Watts Up plugs into any standard 120 VAC outlet
• 15 amp circuit breaker for safety
• True RMS power measured and displayed
• +/- 3%, +/- 2 counts of the displayed value for loads
  above 10 watts
• +/- 5%, +/- 3 counts of the displayed value for loads
  below 10 watts
• Two-tier rate structure
• Displays cumulative cost in dollars/cents
• Displays watts, watt-hours and time
• Changes to local electricity rate
• Input is via 6' electric cord, output is via outlet on top of meter
• Indoor use only
• UL listed 3111-1

• Household lighting
• Refrigerators
• Air conditioners
• All 120 VAC household appliances