Chapter 4 Performing Calibration
34
CellAdvisor JD720C User's Manual
Understanding calibration
Calibration of your instrument to the Open, Short, and Load standards is important to get
reliable and accurate measurement results. After setting frequencies and right before making
a measurement, you need to perform an O-S-L calibration using a mechanical or electronic
calibration kit.
Calibration tools
You need to have the following calibration tools to be able to perform a calibration. This
instrument detects the connected calibration kit and displays a different on-screen instruction
for it.
Mechanical Y-Cal kit or electronic EZ-Cal kit
Extension cable(s) if necessary
Calibration status indicators
This instrument displays calibration status that is an important indicator for you to verify if
your measurement results are reliable and accurate. The calibration status includes CAL ON,
CAL ON (E), CAL ON (I), CAL ON (Q), CAL OFF (T), and CAL OFF. When it changes to CAL
OFF (T) or CAL OFF, you will see the status displayed on the screen for a few seconds and
hear beeping sound as well.
Indicator
Description
CAL ON
Indicates that a mechanical O-S-L calibration is performed using a Y-Cal kit and the
instrument is ready to make a measurement.
CAL ON (E)
Indicates that an electronic O-S-L calibration or e-calibration is performed using JDSU
’s
EZ-Cal kit and the instrument is ready to make a measurement.
CAL ON (I)
Indicates that the frequency setting is changed within the frequency range registered for
the O-S-L calibration and so the calibration is still valid. When the calibration status
changes from CAL ON to CAL ON (I), re-calibration is not necessarily required.
CAL ON (Q)
Indicates that quick calibration (Quick Cal) is performed. It is useful only if cable length
measurement is needed.
CAL OFF (T)
Indicates that the temperature registered during the calibration is changed by ±10
°
C or
greater for center frequency higher than 3 GHz, ±15
°
C or greater for center frequency
between 2 GHz and 3 GHz, and ±20
°
C or greater for center frequency lower than
2 GHz. It is recommended that you perform a new O-S-L calibration to obtain accurate
measurement results. When the temperature comes back within the registered range,
the status may be changed to CAL ON.
CAL OFF
Indicates that the frequency setting is changed off the frequency range registered for the
calibration. The calibration is no longer valid.
