Fluke 78 - Frequency, Dwell, and Duty Cycle Trigger Level Test; RPM Test

78
Service Manual
3-10
3-17. Frequency, Dwell, and Duty Cycle Trigger Level Test
1. Connect the High Accuracy Function Generator output to the z and COM
input terminals on the Fluke 78.
2. Referring to Table 3-5, set the High Accuracy Function Generator for the output
indicated in the steps.
3. Verify that the Fluke 78 display reading is within the limits shown for each function.
Note
For tests: waveform = Triangle and Frequency = 100 Hz.
Table 3-5. Frequency, Dwell, and Duty Cycle Trigger Level Test
Step Function Amplitude
(Peak-Peak)
DC Offset Display Reading
1 Dwell 8.00 V 4.00 V 4-33 to 4-71
2 Duty Cycle 3.40 V 1.70 V 36% to 64%
3-18. RPM Test
1. Connect the High Accuracy Function Generator output to the RPM+ and 10 A input
terminals on the Fluke 78.
Note
Be sure that fuse F1 is installed and intact for RPM to work.
2. Referring to Table 3-6, set the High Accuracy Function Generator for the output
indicated in the steps. Verify that the Fluke 78 display reading is within the limits
shown for each range.
Note
For tests: Waveform = Square and Frequency = 10 Hz.
Table 3-6. RPM Test
Step Range Amplitude
(peak-peak)
DC Offset Display Reading
1 4 V 2 V 1.7 V 1196 to 1204 RPM (2)
2 40 V 2 V 1.7 V 0000 RPM (2)
3 40 V 2 V 3.8 V 1196 to 1204 RPM (2)
4 4 V 2 V 3.8 V 0000 RPM (2)