MR8740、MR8741_user_manual_eng_20191016H.pdf - 第71页
2.7 Performing Calibration (When Mounting MR8990) 59 2 Chapter 2 Measurement Prep arations This procedure compen sates for MR8990 Digital Voltmeter Unit differences. The compensation procedure is performed for all channe…
2.6 Adjusting the Zero Position (Zero-Adjust)
58
This procedure compensates for module differences and sets the reference potential of the instru-
ment to 0 V.
The compensation procedure is performed for all channels and ranges.
Perform zero-adjust in the following cases.
• When an module was changed.
• When power was turned off and on again.
• When settings were initialized (system reset).
• When DC/RMS is switched at the 8971Current Unit (model MR8740 only),
8972 DC/RMS Unit, or U8974 High Voltage Unit
• When measurement mode has been switched on Model U8979 Charge Unit.
• When the ambient temperature has changed significantly.
Zero-position drift
*
may occur.
* Drift: This refers to spurious output caused by a shift in the operating point of an opera-
tional amprifier. Drift can occur due to changes in temperature and due to compo-
nent aging over a period of use.
2.6 Adjusting the Zero Position (Zero-Adjust)
• To obtain precise measurements, provide about 30 minutes warm-up after turning power on to allow
the internal temperature of the modules to stabilize.
• Note that zero-adjust cannot be performed during a measurement.
• During zero-adjust, the mouse operation is disabled. (The procedure may take several seconds.)
Before starting zero-adjust
Procedure
To open the screen: Right-click and select [CHAN] [Unit List] sheet
1
Move the flashing cursor to the [Zero-Adjust]
item.
2
Select [Exec Zero-Adjust].
The zero-adjust procedure is carried out.
• Zero-adjust has no effect on the 8969 and U8969 Strain Unit.
(Perform zero-adjust using Auto Balance.)
See:"7.9.4 Setting Model 8969 and U8969 Strain Unit" (p.165)
• MR8990 Digital Voltmeter Unit performs calibration when zero adjustment is
performed.
See:"2.7 Performing Calibration (When Mounting MR8990)" (p.59)
2.7 Performing Calibration (When Mounting MR8990)
59
2
Chapter 2 Measurement Preparations
This procedure compensates for MR8990 Digital Voltmeter Unit differences.
The compensation procedure is performed for all channels and ranges.
In the following cases, calibration should be executed again.
• When a module was changed.
• When power was turned off and on again.
• When settings were initialized (system reset).
• When the ambient temperature has changed significantly.
2.7 Performing Calibration (When Mounting
MR8990)
• Before performing this procedure, allow the equipment to warm up for about 30 minutes after the
power is turned on to enable the internal temperature of the modules to stabilize.
• Note that calibration cannot be performed during measurement. However, if the calibration setting is
set to ON, calibration is performed at the start of measurement.
• Mouse operations are not accepted during calibration. (The procedure may take several seconds.)
Before starting calibration
Procedure
To open the screen: Right-click and select [CHAN] [Unit List] sheet
1
Move the flashing cursor to the [Zero-Adjust].
2
Select [Execute Zero-Adjust].
Calibration is executed.
2.7 Performing Calibration (When Mounting MR8990)
60