3. Operating Instructions
2. Select the
Horiz. Units
menu item to switch between the different unit options.
All measurements and all traces are immediately updated to reflect the unit change. Time in
nanoseconds (ns) is displayed separately.
3.11.28.2. Fine Vp Control
By default, the CT100B displays three decimal places for Vp; however, the CT100B can display
six decimal places for Vp when very precise distance measurements are needed.
1. Select the
MENU
→
Settings
→
Meas. Settings
menu.
2. Select
Vp 3 Sig Figs
from the menu to toggle the option to
Vp 6 Sig Figs
. The CT100B
will display six decimal places for the Vp readout on the screen when
Vp 6 Sig Figs
is
shown on the menu.
3. When the CT100B is in
Vp 6 Sig Figs
mode, a new function,
Fine Adj. Vp
, is added to
the
M-FUNC
button. When the
M-FUNC
button is set to
Fine Adj. Vp
, turning the
M-FUNCTION
knob will change the Vp value by the 6th significant digit. The Vp value
can be changed by thousandths by setting the
M-FUNC
button to the
Coarse Adj. Vp
function.
3.11.28.3. Relative Reflection Coefficient (RRC) Method
The CT100B measures the relative reflection coefficient between cursors. When the two cursors
of the CT100B are positioned on either side of a change in impedance, this measurement is the
reflection coefficient for that change. The relative reflection coefficient is displayed on-screen
with a prefix of ∆m
ρ
. To view the relative reflection coefficient values, go to
MENU
→
Settings
→
Display
and make sure
Rho
is toggled on. By default, the value is displayed in
Classic
mode,
displaying the true reflection coefficient relative to the signal at the input of the reflection. The
CT100B can also measure in
1502C
mode, which displays a reflection coefficient relative to the
signal at the input of the cable.
1. Select the
MENU
→
Settings
→
Meas. Settings
menu.
2. Select
RRC Classic Mode
from the menu. This will toggle the CT100B between the
Classic RRC
calculation and the
1502C
calculation as displayed on the screen.
3.11.29. User Configurations
The CT100B allows the user to save individually named instrument configurations. A saved
configuration stores the values of all instrument settings that can influence trace measurements.
A configuration can be called up by its name, restoring all settings to the values saved in that
configuration.
User Configurations can reduce operator error when configuring the TDR to make important
measurements. For this reason it is recommended that User Configurations be used when
setting up the CT100B for important measurements, such as quality-control checks on a cable
manufacturing line.
If a configuration named
DEFAULT
is saved, that configuration will be initially employed
whenever the CT100B is powered on.
CT100B TDR Cable Analyzers Operator’s Manual
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