Fluke 287 Fluke 287 and 289 Multimeter Users Manual - Page 32

287/289 Users Manual Making Measurements The following sections describe how to take measurements with the Meter. Measuring AC Voltage The Meter displays ac voltage measurements as rms (root mean square) readings. The rms value is the equivalent dc voltage that would produce the same amount of heat in a resistance as the measured voltage. True-rms readings are accurate for sine waves and other wave forms (with no dc offset) such as square waves, triangle waves, and staircase waves. For ac with dc offset, refer to the "Measuring AC and DC Signals" section later in this manual. Rotate the Meter's rotary switch to V or T and set up the Meter to measure ac volts as shown in Figure 10. The Meter's ac volts function offers a number of modes to provide more details about an ac signal. Pressing the softkey labeled Menu opens a menu of items that can be used to modify the basic ac voltage measurement. Refer to the appropriate section in this manual to learn more about each menu item. To clear all modes and return to the basic volts ac measurement, press the softkey labeled Menu. Move the menu selector to the item labeled VAC. Press the softkey labeled VAC to clear all functions and modes. 22 08:10pm 03 / 13/ 06 123.45VAC Auto Range 0 100 200 300 400 500 VAC Menu Save Setup Switch Box est07.eps Figure 10. AC Voltage Measurements