Keithley 2790, Reference Manual

Page: 149 / 568

4-2 Model 2790 SourceMeter
®
Switch System Reference Manual
Range
The range setting is “remembered” by each measurement function. When you select a
function, the instrument will return to the last range setting for that function.
Measurement ranges and maximum readings
The selected range affects both accuracy of the measurement as well as the maximum
level that can be measured. The measurement ranges and maximum readings for all func-
tions, except FREQ, PERIOD, and TEMP, are listed in
Table 4-1 .
Input values that exceed the maximum readings cause the message “OVERFLOW” to be
displayed.
FREQ and PERIOD
— Frequency measurements from 3Hz to 500kHz and period
measurements from 2µs to 333µs can be made on the ACV ranges.
TEMP
— There is no range selection for temperature measurements. Temperature
measurements are performed on a single, fixed range. Depending on which type of sensor
is being used, the maximum temperature readings range from –200°C to 630°C.
Appendix A , “ Specifications ,” lists the reading range for each sensor type.
Table 4-1
Measurement ranges and maximum readings
Function Ranges
Maximum
reading
DCV 100mV, 1V, 10V, 100V, 1000V ±1010V
ACV 100mV, 1V, 10V, 100V, 750V 757.5V
DCI 20mA, 100mA, 1A, 3A ±3.1A
ACI 1A, 3A 3.1A
Ω
2 100
Ω
, 1k
Ω
, 10k
Ω
, 100k
Ω
, 1M
Ω
, 10M
Ω
, 100M
Ω
120M
Ω
Ω
4
*
100
Ω
, 1k
Ω
, 10k
Ω
, 100k
Ω
, 1M
Ω
, 10M
Ω
, 100M
Ω
120M
Ω
*Offset compensated ohms (OCOMP) can be performed on the 100¾, 1k¾, and 10k¾ ranges.