Hioki 3504-40 C HiTester, Instruction Manual

Page: 64 / 292

4.4 Self Calibration
58
In Model 3504-40, 3504-50, 3504-60, drifts in the measurement values can
be reduced by executing self calibration. Self calibration will acquire the value
needed to adjust the relative error between the current detection circuit and
voltage detection circuit and adjust the drifts of the detection circuits numeri-
cally.
Self calibration has the following modes.
• OFF
Adjust using the default self calibration value.
• MANUAL
When there is a request to start self calibration from EXT I/O, the self cali-
bration value will be acquired and the measurement value adjusted.
However, when the measurement conditions (frequency, level, range) are
changed, the self calibration value will return to the factory default value.
When there is a request to start from communication, the self calibration
value will be acquired and measurement value adjusted at the point when
the first measurement is carried out after the start request.
The measurement value will be adjusted using the most current self cali-
bration value.
• AUTO
The self calibration value is acquired and measurement value adjusted
every time a measurement is carried out.
4.4 Self Calibration

: The same as the left
Supply power
Measurement
(no request for
calibration)
Measurement
(request for cali-
bration)
Changes in mea-
surement condi-
tions (frequency,
level, range)
Measurement
(no request for
calibration)
Measurement
(request for cali-
bration)
OFF Default value
    
MANUAL Default value

Revision Default value

Revision
AUTO Default value Revision Revision Revision Revision Revision
Operation command
to the device
Measurement speed,
self calibration
• Always connect to the object to be measured and set the measurement
conditions (frequency, level, range) for the evaluation before acquiring the self
calibration value. When the measurement conditions (frequency, level, range)
are changed, the current self calibration value will be disabled automatically
and returned to the factory default value.
• If the interval between taking the self calibration value and the next measure-
ment becomes long, drift will occur between the time the self calibration value
was obtained and the current circuit conditions, reducing the effectiveness of
self calibration. Please make the interval after taking the self calibration value
as short as possible.
Take a new self calibration value after measuring if the ambient temperature
has changed by more than 2

C.
• This device requires one hour of warm up time after it is turned on.
The circuit error is different from after warm up so always acquire the self
calibration value after warm up.
• When acquiring the self calibration value, the analog measurement time
(INDEX) and measurement end time (EOM) become longer.
See
7.4 "About Measurement Times" (p. 128)
• When an abnormal self calibration value is acquired when the instrument to
be tested is not connected or self calibration is conducted in a noise environ-
ment, ERR will light up. When this happens, connect the instrument to be
tested correctly, or carry out measures to reduce noise then try self calibration
again to deactivate ERR.