The Wattmeter is an extremely easy-to-use multimeter, able to performs the Ampere, Volt, and Watt measurements (in this version for DC or slowly changing signals, with a few modifications for any signal type). It is designed for application with absorption up to 75 A, in a voltage range of 0-19 V. By the user point of view, it is mainly composed by:

• Power on switch (the power supply is guaranteed by a standard 9V battery)
• 4 digit display
• Three position switch for measurements selection
• Four 4-millimeter socket connector

At the power on the wattmeter have to be leaved unconnected due to the zero-calibration (about 5 second long) of the current transducer. At the end of this automatic operation, that is announced by a countdown on the display, the operator can choose the measurement mode (Ampere, Volt, or Watt) by the trhee position switch.