BERTHOLD TECHNOLOGIES LB 567, Руководство пользователя

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Chapter 8. Start-up of MicroPolar 2 ++
MicroPolar 2 (++) LB 567
59
Chapter 8.
Start-up of MicroPolar 2 ++
System adjustment and calibration are carried out in just the
same way for MicroPolar 2 ++, as they are for the standard
system MicroPolar 2. However, please keep in mind that the
++ unit requires a minimum attenuation of 50 dB over the
entire concentration range and during system adjustment.
When falling below, the measurement is not precise anymore.
The total attenuation is calculated as follows:
dB
total
= dB
adjust
+ dB
live
+ 0.4 x signal cable length
Eq. 8-1
where:
dB
total
: Total attenuation
dB
adjustment
: Attenuation during system calibration
dB
live
: Current attenuation in the measure-
ment mode
Signal cable length: e.g. 4 m HF-cable quad results in 8 m
signal cable length (to and from)
The evaluation unit monitors the entire attenuation automati-
cally and reports a falling below by an error message (error
no. 55).
Remedy when falling short of the attenuation:
If the required overall attenuation is not reached, you have
the option to install a 10 dB fixed attenuator into the transmit-
ting branch (see Fig. 8-1). The standard model MicroPolar 2
should be used if the attenuation is clearly below the required
value.
Figure 8-1:
Assembly of the
10 dB attenuator
Micro-Polar
M-Tx
M
-T
x
M-Rx
M
-R
x
R-Tx
R
-T
x
R-Rx
R
-R
x
N-attenuator 10dB
(ID-No. 20613)
HF-cable quad