Revised August, 2004
10 TEGAM WAY • GENEVA, OHIO 44041 • 440-466-6100 • FAX 440-466-6110
•
5-3
MAINTENANCE
5.5
Calibration
WARNING
DISCONNECT
THE
AC
POWER
CABLE
BEFORE
REMOVING THE INSTRUMENT FROM ITS CASE. LETHAL
VOLATEGS ARE PRESENT WITH AC POWER CONNECTED.
Remove the four large mounting screws from the front
panel and remove the instrument from the case. The
binding posts and switch knobs may be held to assist in
removal. Note that the unit must be extracted carefully to
avoid catching the internal boards on the retaining brackets.
For calibration, only, it is not necessary to separate the
printed circuit boards. There are three trimpots on the lower
edge of the display board which may be adjusted for
calibration.
WARNING
USE EXTREME CARE IN HANDLING THIS UNIT! EVEN
WITHOUT OPERATING THE TEST PUSHBUTTON, THERE
ARE VERY HIGH VOLTAGES PRESENT! THEY COULD BE
LETHAL!
1.
Connect the power cord and remove the test cables. Set
the test voltage to 50 V and the Ohms range to 1 GΩ.
2.
To adjust R29 (see Figures 7a and 8), connect the
voltmeter Low lead to R27, the side closest to D6.
Connect the High lead to R26, the side between R26 and
R20. Turn the power on. DO NOT TOUCH ANYTHING
EXCEPT THE SCREW ADJUSTMENT OF R29! Adjust R29
for 0 ± 0.1 V on the voltmeter. Turn the power off.
3.
To adjust R32, connect the voltmeter High lead to R22,
the side closest to S1. Turn the power on. DO NOT
TOUCH ANYTHING EXCEPT THE SCREW ADJUSTMENT OF
R32! Adjust R32 for 0 ± 0.1 V on the voltmeter. Turn
the power off and remove the voltmeter leads.