QuadTech 1865, Инструкция по эксплуатации, Страница: 30 / 87

Page 30 of 87 Operation
Power is applied to the 1865 by pressing the [POWER] button on the front panel. The
instrument runs a self test and any error messages are displayed accordingly (refer to
paragraph 2.8).
2.3 Zeroing
Before making measurements, the 1865 instrument should be zeroed to correct for test
lead or fixture errors. During the zeroing process corrections are calculated and stored in
instrument memory and applied to ongoing measurements. Generally the unit should be
zeroed at least once per day and each time test leads or fixtures are changed. The zeroing
routine is accessed through the Utilities Menu by selecting [ZERO], instructions are
given on the LCD display. Refer to paragraph 2.6.4.3.
2.4 Connection to Device Under Test
Figure 2-1 illustrates the front panel input terminals and a basic block diagram of their
function.
Q uadTech
+
1865
Megohmmeter
IR Tester
!
-
GUARD
+ -
GUARD GND
(Earth)
Range
Select
Zin
5k
Ω
-
+
Figure 2-1: Input Panel and Block Diagram
An optional shielded lead set is available for use with the 1865 unit, QuadTech part
number 1865-51. How the connection to the DUT is made depends on the device being
measured: if it is a grounded, ungrounded or guarded device. The 1865 instrument is
supplied with two resistor adapters which are recommended for use only when measuring
high value, low leakage capacitors. These are to be added in series with the (-) terminal
lead to eliminate fluctuating test results when measuring this type of device. Refer to
paragraph 3.3.
CAUTION
DO NOT GROUND the (-) negative unknown terminal, invalid measurements will result.