NF ZM2371, Instruction Manual

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3.5 Basic Operations
3-44 ZM2371/ZM2372
3.5.6.6 Correction of Measurement Error
The
ZM2371 / ZM2372
can correct the following errors that will occur by a measurement
fixture or connection cable.

Zero correction
OPEN correction Error due to the stray admittance that remains when measurement
terminals are opened
SHORT correction Error due to the residual impedance that remains when
measurement terminals are shorted
The zero correction can be made either in full frequency range or at one point of current
frequency only.

LOAD correction
Deviation from true value
Correction is made so that an error becomes zero when the standard
having exact values is used under specific measurement conditions
including the frequency and signal level. The LOAD correction cannot
be made individually but executed together with the zero correction.

Cable length correction
Additional error due to the connection cable
This correction is made for the measurement range of high impedance.
For the measurement range of low impedance, originally additional
error is small and therefore this correction presents less effect.
Setting of current correction is shown on the second line of measurement screen.
A 1 0 0

F A S T 2 5 6 I n t OpShLd1m
CORRECTION
Op OPEN: Indicates the OPEN correction is enabled. (Blank when disabled)
Sh SHORT: Indicates the SHORT correction is enabled. (Blank when disabled)
Ld LOAD: Indicates the LOAD correction is enabled. (Blank when disabled)
1m 0m / 1m / 2m / 4m: Indicates a setting of cable length correction.

Measurement signal level when measuring correction values
The OPEN, SHORT or LOAD correction value is measured on the measurement signal level
at that time. It is recommended to measure each correction value when the measurement
signal level was changed since a correction value varies depending on the measurement
signal level.
Varying measured value obtained every measurement of correction value means that the
correction value will vary. When the measurement signal level is small, it is recommended to
measure a correction value on larger measurement signal level. For the correction at specific
frequency only, disable the correction once, and set large averaging count to restrict
variations and measure correction values, and then set spot OPEN correction value and spot
SHORT correction value, so that more exact correction can be made.

DC bias when measuring correction values
Regardless of the DC bias setting, during the measurement of OPEN correction value and
SHORT correction value, the DC bias is turned off automatically only during that
measurement. With the DC bias turned on, the OPEN correction value and SHORT
correction value cannot be measured.