5. Three-Term & 12-Term Correction
5.1 Fundamentals
In the scope of this manual the three-term correction is abbreviated with
TTC
(or DTTC for differential modes) and the twelve-term correction with
12TC
. TTC and 12TC are powerful tools to reduce systematic errors of the
measurement system. Activating TTC/12TC leads to a
significantly increas-
ing accuracy
of the measurement results and is therefore
highly recom-
mended to be used
whenever applicable. To reduce time and effort for
performing the required TTC/12TC calibration measurements some useful
tools are integrated in the software to simplify and speed up your work.
5.2 Requirements
The fundamental mechanisms of the TTC/12TC are adopted from frequency
domain methods and enhanced with newest TDR data-processing algorithms.
For using TTC/12TC the following requirements must be fulfilled:
1.
A calibration kit (open, short, load = OSL) must be available for per-
forming the required TTC measurements. These are available from
Sequid and/or other third party vendors.
2.
In addition to the OSL-standards, a thru standard must be available
(OSLT) for applying 12TC calibration.
3.
A configuration file containing the coefficients of your specific cali-
bration kit (e.g.
my_calkit.ckd
) must be either copied to the pro-
grams
Config
subfolder (administrator privileges required) or installed
at runtime via the
Main Window
menu entry
File
→
Install
(installa-
tion for current user only).
4.
Please
Sequid GmbH for further information about how to
create the
ckd
file for your specific calibration kit. If a calibration kit
is shipped with the device, the
ckd
file is included.
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