Keithley 2100 User Manual

4-28 Return to Section Topics 2100-900-01 Rev. D / September 2011
Section 4: Front Panel Operations Model 2100 6 1/2-Digit Resolution Digital Multimeter User’s Manual
The dB feature takes a DC or AC voltage measurement and displays it in decibel units that
correspond with a relative reference value. The calculation of dB is listed below:
dB = 20 x log(Vin / Vref)
or
dB = (Input signal in dBm) - (relative value in dBm)
NOTE The Vin is the input signal and the Vref is the relative reference.
The dB measurement is applied to DC and AC voltage only. The relative value is adjustable (from
0dBm to 200dBm) and is stored in volatile memory.
Setting the relative reference value
You can either manually select a number for the relative reference, or let the multimeter take the
first reading (0dB):
To set the relative reference value from the front panel:
1. Press the CONFIG + SHIFT + NULL keys.
2. Use the PREV and NEXT keys to move through the digits and the up and down arrow keys
to increase or decrease the numbers to the desired value.
3. Press ENTER to set the value (refer to Figure 4-23).
Figure 4-23
Setting the relative reference value
To make a dB measurement from the front panel:
1. Select the measurement function by pressing one of the DCV or ACV keys.
2. Enable the dB operation by pressing SHIFT + NULL keys.
3. After enabling the dB operation, you can set or alter the dB relative value as mentioned
above.
4. Observe the displayed reading (refer to Figure 4-24 for the location of the keys used).
NOTE Press SHIFT + NULL again to disable this feature. The "MATH" annunciator on the
display indicates the state of a mathematical feature.
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
NULL
ENTER
SHIFT
CONFIG

Keithley 2100 Specifications

General

Brand	Keithley
Model	2100
Category	Multimeter
Language	English