Fluke 45 user manual Selecting A Function Modifier, K, I, H, J

45

Users Manual

Table 3-7. Maximum Sinewave Inputs for Frequency Measurements

Range

300mV

3V

30V

300V

750V

Maximim Input Voltage

1 V rms

6 V rms

60 V rms

750 V rms

750 V rms

The input signal sensitivity is listed under the frequency specifications in Appendix A. These values are based on sine waveforms. The signal level must be increased for lower crest factor inputs (the crest factor is the ratio of the peak voltage to the ac rms voltage of the waveform). If the input signal is below the required level, the frequency will be displayed as zero. If the measurements are unstable, the input signal may be near the threshold level.

Selecting A Function Modifier

(K, I, H, J)

Selecting a function modifier (see Figure 3-7) causes the meter to perform an action on an input (e.g., convert to decibels or compare to another value) before a reading is displayed. Function modifiers can be used in combination. (See “Using Function Modifiers in Combination," later in Chapter 3.)

To use a function modifier, press a function button to select a primary function, then press a function modifier button (or buttons). Modified readings are shown only on the primary display.

After a function modifier has been selected, pressing any (white) function button turns off all modifiers, causes the secondary display to go blank, and returns unmodified readings to the primary display.

3-10