BERTHOLD TECHNOLOGIES LB 567, User Manual

Page: 31 / 186

Chapter 3. System Description
MicroPolar 2 (++) LB 567 31
3.7.5 High-frequency Cable
High-frequency cables (HF cable) are used to transmit microwave
signals.
HF cables change their conductivity (for microwaves) with tem-
perature and would therefore produce measurement errors with
varying ambient temperature. This error is compensated for by
enabling the automatic cable compensation. The influences of the
ambient temperature on the signal cable are compensated for by
means of the reference cable. To this end, the sum of the refer-
ence cables has to match the length of the sum of the signal
cables.
Two different HF cable types of different lengths are available:
Version 1: The so-called HF-cable quad: It consists of four single
HF-cables of equal length, whose ends are terminated by one HF-
connector (N-type). Available cable lengths: 2, 4, 6 and 10 m
(see Figure 3-15).
The HF-cable quad is used exclusively for the flow cell . The ref-
erence line on the probe side is short-circuited using an N-con-
nector (see Figure 3-16).
Figure 3-15:
HF cable quad
Lengths 2, 4, 6 and 10 m
Corrugated tube
4 x N-connector
ø
18.5 mm
0.35 m
0.35 m
4 x N-
4 x N-connector
Figure 3-16:
HF cable quad
probe side:
The ends of the
reference line
R-Rx and R-Tx are
short-circuited
using an
N-connector.
N-connector
(ID-no. 20608)
Sensor side
R-R
x
R-Tx
M
-R
x
M
-Tx