Measuring electricity use
Watt-meters are devices that measure power, power factor, current, voltage, duty-cycle, and maxima and minima of those parameters. Some devices have memory chips that allow them to record samples of the data every second, which students can upload to a computer for analysis.
EnergyTeachers.org sells WattsUpPro data-logging meters at wholesale cost to teachers and schools. There are many open-inquiry possibilities, answering questions such as "When does my microwave oven use more energy, when it's warming food, or the rest of the day when it's just running its clock?"
With watt-meters, students learn about:
*Power as a rate of energy exchange.
*Electricity bills, and what household appliances contribute to that bill.
*What duty-cycle means, and what it can tell us about refrigerators. A refrigerator or some other devices that are usually on are working too hard, an appliance only working 5% of the time may be oversized for the job.
Related Topics in our Links section
Related Static Documents(old system)
- Data in the Classroom Workshop Guide