HP 8568B manual Location of High Voltage Adjustments

Note

2. High-Voltage Adjustment (SN 3001A and Below)

The accuracy of the high-voltage probe is specified for a probe connected to a dc voltmeter with 10 M62 input resistance. HP 3456A and HP 3455A digital voltmeters have a 10 MQ input resistance on the 100 V and 1000 V ranges. All measurements in this procedure should be performed with the DVM manually set to the 100 V range (fOO.OOO on the HP 3456A display).

r,

P

AlA H I G H

V O L T A G E

R E G U L A T O R

I

,AlA8DSl

- AlA7TP3

. AlA6R32

Warning

Figure 3-6. Location of High Voltage Adjustments

4.Set the LINE switch to ON. Set the front-panel INTENSITY control fully counterclockwise (CRT beam at cut-off) to prevent possible damage to the CRT.

5.Note the DVM indication at AlA7TP3.

DVM Indication:

6.Connect the high-voltage probe to the DVM. Connect the probe to AlA7TP3.

7.Note the DVM indication.

DVM Indication:

8.Divide the DVM indication in step 7 by the DVM indication in

step 5. This gives the calibration factor needed to compensate for high-voltage probe error.

Calibration Factor:

9.Disconnect the high-voltage probe from AlA7TP3. Set the LINE switch to STANDBY. Remove the ac line cord from both instrument sections.

The MAINS power-on indicator AlASDSl (red LED) should be completely off before proceeding with this procedure. See Figure 3-6. The indicator will remain lit for several seconds after the ac line cord has been removed, and will go out slowly (the light becomes dimmer until it is completely out).

Adjustments 3-3 1