Technical data
Agilent B2900A Configuration and Connection Guide, Edition 1 3- 17
Connection
Connection with Prober
• For the non-Kelvin connection, the voltmeter measures the voltage drop of resistance
r
F1
,R
DUT
, and r
F2
.
• For the Kelvin connection, the voltmeter measures the voltage drop of resistance R
DUT
only. The impedance of the voltmeter is very high, so the voltage drop of resistances
r
S1
and r
S2
can be ignored.
The Kelvin connection is effective even when forcing voltage. The voltage drop due to the
residual resistance of the Force line wiring is fed back to the voltage source via a
comparator in the Sense line. The input impedance of comparator is high, and current flow
into the Sense line is very low. So output error is not significant if the Sense line wiring has
a residual resistance of 10 or less. Therefore, the specified voltage appears at the sense
point (point where Sense line contacts Force line).
WARNING Do not touch the guard terminal with bare hands because you may be shocked by
high voltage. The potential of the guard terminal is equal to the output voltage.
CAUTION Never connect the Guard terminal to any other output, including circuit common, chassis
ground, or any other guard terminal. Doing so will damage the B2900A.
NOTE Kelvin connection and non-Kelvin connection
To make the Kelvin connection, use both Force and Sense terminals. Connecting the Force and Sense
lines together at the terminal of the DUT (device under test) minimizes the measurement error caused
by the residual resistance of the connection cables. The Kelvin connection is effective for the low
resistance measurement and the high current measurement.
If you want to simplify the cable connections, use the 2-wire connections by connecting the Force
terminals only. Then open the Sense terminals. This is the non-Kelvin connection. The Force
terminals can be used to force and measure dc voltage or current.