Fluke 279FC User Manual - Page 29

Volts/Hertz Ratio The Multimeter can show the ratio of volts to frequency of the ac signal. See Figure 6. When the Multimeter is set to the Volts/Hz function, the voltage range is set to manual. If the voltage increases to a value larger than the range, the Multimeter shows OL in the display. If the voltage drops to less than 5 % of the range, the value shown in the display can be invalid. Low-Pass Filter AC measurements use an ac low-pass filter (). The filter blocks unwanted voltages above 1 kHz. See Figure 5. The lower frequency voltages pass with reduced accuracy to the measurement below 1 kHz. The low-pass filter can improve measurement performance on composite sine waves that are typically generated by inverters and variable frequency motor drives. 1 kHz 100 Hz Figure 5. Low-Pass Filter True-rms Thermal Multimeter Basic Measurements x1 HzAC x2 V/HzAC iFlex Figure 6. Volt/Hertz Ratio 19