Check Vertical Position Accuracy - Tektronix TDS1000B Series Service Manual

Check Vertical Position
Accuracy
TDS1000B and TDS2000B Series Oscilloscope Service Manual
12. Set the oscilloscope SEC/DIV to 2.5 ns/div.
13. Push SET TO 50%. Adjust TRIGGER LEVEL as necessary and then
check that triggering is stable.
14. Change the oscilloscope setup using the following step:
Push menu button
TRIGGER
15. Push SET TO 50%. Adjust TRIGGER LEVEL as necessary and then
check that triggering is stable.
16. Disconnect the test setup.
The results of this test and the DC Gain Accuracy test together define the DC
Measurement Accuracy of the oscilloscope. The DC Measurement Accuracy
specification encompasses two different ranges of operation over two different
attenuator settings:
H DC Gain Accuracy: Identifies errors, mostly from the A/D converter, when
the vertical position (known as offset in these oscilloscopes) is set to 0
divisions (or a grounded input will show screen center)
H Vertical Position Accuracy: Identifies errors, mostly from the position
control, made when the vertical position is set to a non- -zero value
The two attenuator settings operate identically, so verification of the attenuation
range from - -1.8 V to 1.8 V also verifies the attenuation range of - -45 V to 45 V.
To set up the test, follow these steps:
1. Set up the oscilloscope as shown in the next table.
Push menu button
DEFAULT SETUP
CH 1, CH 2, CH 3, CH 4
CH 1, CH 2, CH 3, CH 4
TRIGGER
ACQUIRE
Select menu option
Slope
Select menu option
—
Probe
Volts/Div
Source
Mode
Sample
Performance Verification
Select setting
Falling
Select setting
—
1X
50 mV/div
Ext*
Auto
—
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