Keithley 2100 User Manual

2100-900-01 Rev. D / September 2011 Return to Section Topics 4-21
Model 2100 6 1/2-Digit Resolution Digital Multimeter User’s Manual Section 4: Front Panel Operations
or used to perform mathematical operations on the readings. Note that these math operations are
available to all measurement functions except continuity and diode testing.
NOTE The "MATH" annunciator on the display indicates the state of a mathematical feature and
will be lit when any math feature (excluding Ratio) is enabled. Press the same keys again
to disable the math feature.
NOTE When you press the RATIO key, the "RATIO" annunciator is lit on the display.
Ratio
Definition
The Ratio function calculates the ratio of an input DC voltage to a reference DC voltage, using the
following equation:
How to make a Ratio measurement
There are two ways to make a Ratio measurement: Using the front panel, or using a remote
interface.
To make a Ratio measurement from the front panel:
1. Use the INPUTS button to select the front or rear terminals.
2. Connect the DC input signal to the INPUT HI and LO terminals. Connect the reference
signal to the SENSE HI and LO terminals. Connect the SENSE LO to the INPUT LO
terminal.
3. Press CONFIG + RATIO, then use the PREV and NEXT keys to select the 
RESOLUTION option (refer to "Resolution settings (digits)") and press ENTER.
4. Select the desired value by pressing the left, right, up, and down arrow keys, then press
ENTER.
5. To start the Ratio function, press the RATIO key and observe the reading on the display
(Figure 4-16 shows the location of the keys used).
NOTE To close this function, press one of the measurement function keys.
Figure 4-16
Making a Ratio measurement from the front panel
DC input voltage
DC reference voltage
Ratio =
FILTER
NEXT
PREV
DIGITS
RATIO
%
MIN/MAX
NULL
ESC
ENTER
AUTO
SINGLE
TRIGGER
STORE
RECALL
LOCAL
SHIFT
CONFIG
MENU
AUT O
DCV
ACV
22
FREQ
CONT
TEMP
4 WIRE
RATIO
V
INPUT
PEAK
200V
PEAK
HI
LO
PEAK
500V
3A
RMS
INPUTS
3A 250V
FRONT/REAR
AMPS
R
1000V
REF
CAT 1000V
CAT 600V
LOCK
SETUP
ACV
22
FUNCTION
DCI ACI
4
PERIOD
LIMITS MX+B
dB
EXTRIG
HOLD
MATH
TRIGGER MEMORY
dBm
RANGE
DISPLAY
NEXT
PREV
POWER
OFF
ON
SENSE
F
NEXT
PREV
RATIO
ENTER
CONFIG
INPUTS

Keithley 2100 Specifications

General

DC Voltage Range	100 mV to 1000 V
AC Voltage Range	100 mV to 750 V
Resistance Range	100 Ω to 100 MΩ
Continuity	Yes
Diode Test	Yes
Frequency Range	3 Hz to 300 kHz
DC Voltage Accuracy	0.0035%
DC Current Range	100 µA to 10 A
DC Current Accuracy	0.05%
AC Current Range	100 µA to 10 A
Frequency Accuracy	0.01%
Capacitance Range	1 nF to 10 mF
Temperature Range	-200 °C
Connectivity	RS-232
Type	6.5-digit digital multimeter