Agilent Technologies 4156b, Руководство пользователя

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3-66 Agilent 4155B/4156B User’s Guide Vol.2, Edition 5
Measurement Functions
Zero Offset Cancel
Zero Offset Cancel
The 4155B/4156B has zero offset cancel function. This function allows you to
minimize measurement error (offset) caused by resistance and leakage current of
cables, prober, and so on.
You can use the zero offset cancel function for:
• low current measurement (measurement range
£
10 nA) by SMUs.
• differential mode V measurement by VMUs.
To Measure Offset Data
To measure the offset data, do following:
1. Select the measurement range in the MEASUREMENT RANGE table on the
MEASURE: MEASURE SETUP screen. See Table 3-10 for the ranging mode
available.
2. Open the measurement terminals at the cable end of the device side.
3. Press green key and Stop front-panel key in this order. The ZERO CANCEL
field is automatically set to ON, and offset data is measured. This data is used
for the offset cancel.
Allowable offset value is shown in Table 3-11. If offset data is too large, offset
measurement for this measurement path is not performed. For this path, an * is
marked in the ZERO CANCEL table. Then the previous data is used for the
offset cancel. The initial offset data is 0.
NOTE During offset measurement, integration time is automatically set to specified time or
medium, whichever is longer. After offset data measurement, integration time
returns to same setting as before the offset measurement was performed.
NOTE After you perform the offset measurement, if you change the ranging mode to 10 nA
limited auto or 10 nA fixed and you try to perform the offset measurement again, the
offset data is not measured for this unit. But the previous offset data is effective. So
the offset cancel can be performed for this unit using the old offset data.