Tektronix CSA7404B - Table 4- 13: Dark Level

Performance Tests
4- 126
CSA7404B, TDS7704B, TDS7404B, TDS7254B & TDS7154B Service Manual
d. Check that the Status is Pass.
e. From the tool bar, touch Vert and select the Chan 1 tab.
f. Select a Wavelength.
3. Follow this procedure to calibrate the Dark Level:
a. Press Dark Level Calibration and wait for the compensation to
complete.
b. Wait until the compensation is completed.
c. Check that the Status is Pass.
4. Initialize the instrument: Press the DEFAULT SETUP button.
5. Modify the initialized front-panel control settings:
H From the tool bar, touch Meas and select the Ampl tab.
H Touch Mean.
H From the tool bar, touch Horiz and select the Acquisition tab.
H Touch Average and set the number of averages to 64.
H Touch the Close button.
H Set the Vertical SCAL E to 10 W.
Table 4- 13: Dark level
Scale setting Accuracy limits
10 W ≤2. 6 W
20 W ≤3. 6 W
50 W ≤6. 6 W
6. Confirm Dark Level is within limits: Do the following substeps — test the
scale settings in Table 4--13.
a. Select an unchecked scale setting from Table 4--13.
b. CHECK that the CH 1 Mean readout is within the limits listed for the
current scale setting in the table. Record the mean on the test record.
7. Repeat step 6 until all scale settings have been checked.