Tektronix TCP300A, User Manual

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Control Summary
6. The current probes connect to the TCPA300 and TCPA400 at the PROBE
INPUT connector.
7. The COUPLING button selects AC or DC probe coupling, as indicated by
the LEDs.
8. The RANGE button toggles between the two scale factors that are available
for the attached probe (TCPA300 only). LEDs indicate the selected range.
TCPA300 and TCPA400 Controls
These front panel controls and indicators are common to both the TCPA300 and
TCPA400 current probe ampli
fi ers, unless otherwise indicated.
PROBE DEGAUSS
AUTOBALANCE Button
and Indicator
When pressed, this button performs two functions that maximize measurement
accuracy. First, the ampli
fi er generates a degauss signal to remove any residual
magnetism from the attached current probe. Second, the ampli fi er initiates an
operation to remove any undesired DC offsets from the circuitry. During the
degauss process, the ampli
fi er is busy and cannot be used to measure current.
The indicator light next to the PROBE DEGAUSS AUTOBALANCE button
blinks red whenever the ampli
fi er detects that the current probe needs degaussing.
The ampli fi er cannot detect all circumstances that require probe degaussing,
so you may need to degauss the probe at times when the PROBE DEGAUSS
AUTOBALANCE light is not blinking red. The red blinking light serves as a
reminder to degauss the current probe when one of the following conditions
occurs:
The ampli fi er has just been turned on with a current probe connected.
The current probe has been changed.
An overload was detected.
To perform the probe degauss/autobalance function, remove the probe from
all conductors (or ensure that the conductor under test has no power), make
sure the probe is locked closed, and then press the
PROBE DEGAUSS
AUTOBALANCE button. The probe degauss/autobalance routine will not pass
if the current probe is disconnected from the ampli fi er input, or if it is unlocked
(the PROBE OPEN LED is on).
The indicator blinks orange during the time the ampli fi er is busy performing
the probe degauss functions. When the degauss and autobalance procedure is
complete, the indicator light turns green.
18 TCPA300/400 Ampli fi ers and TCP300A/400 Series Current Probes User Manual