B. Operator Performance Checks
B.4.12 Cursor Readout Range Check
1. In the Measurement menu, toggle on Extra Long Mode.
2. Turn the HORIZONTAL SCALE knob counterclockwise until horizontal scale is maximized.
3. Using the M-FUNC button and M-FUNCTION knob, set Vp to 1.000.
4. With the HORIZONTAL SCALE knob, position a cursor at the most far right position
possible.
5. The absolute distance measurement for the cursor is the upper limit for cursor readout range.
This number should be larger than 12,000 m or 40,000 ft.
6. Position a cursor at the most far left position.
7. The absolute distance measurement for the cursor is the lower limit for cursor readout range.
This number should be less than -1 ft. (-0.3 m).
B.4.13 Cursor Readout Resolution Check
1. Use the HORIZONTAL SCALE knob to set the horizontal scale to 0.00330 ft./div or
0.001 m/div.
2. Position a cursor on the screen and note the absolute distance measurement for the cursor.
3. Move the cursor the smallest possible step using the HORIZONTAL POSITION knob. The
difference between the new distance measurement and the previous is the minimum cursor
readout resolution.
B.4.14 Distance Measurement Accuracy Check
Accuracy is determined by taking a cable of known length and velocity and comparing the known
values against measured values. Accuracy is reported as a percentage. When determining accuracy,
ensure that horizontal calibration has been performed accurately.
Accuracy should be checked for Short, Medium, and Long settings.
B.4.15 Ohm Readout Range Check
1. Connect the 36 in. reference cable to the CT100B.
2. Position a cursor on the trace well beyond the end of the cable. The vertical impedance
measurement should read ≥ 1.5k ohms.
3. Position a cursor on the trace well before the leading edge of the pulse. The vertical
impedance measurement should read ≤ 0.1 ohm.
B.4.16 Resolution Check
Position a cursor at a point of the trace where the vertical impedance measurement is greater than
0.1 ohm and less than 1500 ohms. The CT100B should display 3 digits for this measurement.
CT100B TDR Cable Analyzers Operator’s Manual 119
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