Z E S ZIMMER Electronic Systems GmbH Chapter 12
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12.3.1.1 Requirements for reference instruments
As generally known the references, calibration sources and/or reference power meters, have to
be in an accuracy class, which is at least 3 time better than the instrument. An optimal value is
from 5 to 10 times better.
For the allowed error of the LMG to be calibrated please refer also to chapter 12.1.1,
‘Accuracy of measured and computed values’
12.3.2 Adjustment
The adjustment has to be done at (23
±
1)°C.
ZES ZIMMER offers in principle a way to adjust the instruments outside our factory, if some
technical preconditions are fulfilled. For further information, please contact [email protected]
12.3.3 Zero adjustment of the instrument
The zero settings of the LMG450 can be adjusted without sending the instrument back to the
factory. For this purpose remove ALL measuring cables from the instrument and switch to the
normal measuring mode. Now short circuit the voltage input (U* and U). Short circuit means,
not to connect the inputs with any wire but to connect them as short as possible to get a
minimised loop area!
If you want to adjust external sensors connect them, switch to external sensors in the range
menu and don’t enclose any measuring lead with the sensor.
Warm the instrument up for a minimum of 2h.
Now press Z-Adj in the Misc. menu (see 4.4.1, ‘Misc.’).
Answer the warning with Enter if you have setup the instrument correctly. After about 1
minute the instrument is adjusted and a message appears.
If you are in doubt about any detail of this adjustment please contact the manufacturer.
This adjustment is active, while the instrument is switched on. If you switch off and on the
instrument, the factory values are loaded.
12.3.4 Fans
The air filter of the fan near the power supply socket has to be cleaned (depending on the
environment two times per year). To do this remove the shield of the fan. When doing this you
should check the correct working of this fan.
Содержание LMG450
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