User manual

3-10 Basic Source-Measure Operation 2400 Series SourceMeter
®
User’s Manual
Operation considerations
The following paragraphs discuss warm-up period, auto zero, V-source protection,
and source delay.
Warm-up
The SourceMeter must be turned on and allowed to warm up for at least one hour
to achieve rated accuracies See Appendix A for specifications.
Auto zero
Every A/D conversion (reading) is calculated from a series of zero, reference, and
signal measurements. With auto zero enabled, all three of these measurements
are performed for each reading to achieve rated accuracy. With auto zero dis-
abled, zero and reference are not measured. This increases measurement speed,
but zero drift will eventually corrupt accuracy. With auto zero disabled, periodically
change measurement speed.
Temperature changes across components within the instrument can cause the
reference and zero values for the A/D converter to drift due to thermo-electric
effects. Auto zero acts to negate the effects of drift in order to maintain measure-
ment accuracy over time. Without auto zero enabled, measurements can drift and
become erroneous.
Front panel auto zero
Set the auto zero from the front panel as follows:
1. Press the MENU key.
2. Select A/D CTRL from the main menu, then press ENTER.
3. Select AUTO ZERO, then press ENTER.
4. Select ENABLE or DISABLE as appropriate, then press ENTER.
5. Press EXIT as necessary to return to normal display.
Remote command auto zero
Use the :SYSTem:AZERo command to enable or disable auto zero via remote.
See Section 18, “SYSTem subsystem.” For example, send the following com-
mand to disable auto zero:
:SYST:AZER ON
Conversely, send this command to disable auto-zero:
:SYST:AZER OFF