User manual

7-2 Range, Digits, Speed, and Filters 2400 Series SourceMeter
®
User’s Manual
Range and digits
Range
The selected measurement range affects the accuracy of the measurements as
well as the maximum signal that can be measured. Note that with the output off,
dashed lines are displayed (i.e., --.---- µA) to indicate that measurements are not
being performed.
Maximum readings
The full scale input for each voltage, current, and auto ohms measurement range
is defined by the selected range. For example, ±2.11V is the full scale reading for
the 2V range, ±105.5mA is the full scale reading for the 100mA range, and
±2.11kΩ is the full scale reading for the 2kΩ range. Table 3-1 in Section 3 lists the
full scale readings for all ranges.
For manual ohms measurements, the display reading is the result of the V/I calcu-
lation. Effectively, there are no ohms ranges. Thus, there are never any leading
zeroes in the display reading. For example, a resistor that is measured at
936.236kΩ will be displayed as 936.236kΩ (5H digit resolution). The RANGE keys
are used to select the voltage or current measurement range.
Input levels that exceed the maximum levels cause the “OVERFLOW” message
to be displayed, while 9.91E+37 will be returned via remote.
Ranging limitations
When sourcing voltage (Source V), you cannot use the RANGE keys to change
the voltage measurement (Measure V) range. Also, when sourcing current
(Source I), you cannot use the RANGE keys to change the current measurement
(Measure I) range. For these source-measure configurations, the measurement
range is determined by the selected source range. See Appendix A for ranges.
Manual ranging
For the Source V Measure I, Source I Measure V, and Ohms configurations, the
RANGE arrow keys are used to select a fixed range. Note that the highest avail-
able range is dependent on the corresponding compliance setting.
Within range compliance or if the instrument displays the “OVERFLOW” message
on a particular range, select a higher range until an on-range reading is displayed.
Use the lowest range possible without causing an overflow to ensure best accu-
racy and resolution.