Current Measurements - Keithley 2000-SCAN-20 Instruction Manual

Current measurements

Current shunts can be installed on the circuit board to measure indirect AC and DC currents
through channels 1 and 11 only. The following paragraphs discuss installing current shunts and
the basic methods used to determine currents.
CAUTION
Current shunt locations
Figure 2-7
channel 11, and location R104 is for channel 1.
Figure 2-7
Current shunt locations
R103 (Channel 11 Shunt)
Recommended current shunt values
Hole spacing on the circuit board is intended for 1/10W resistors. The resistance value will
depend on the current you intend to measure; 1kΩ resistors should be optimum for many appli-
cations. A 1kΩ resistor will allow you to switch currents up to 10mA without exceeding the
power rating of the resistor.
For larger currents, decrease the shunt value. Conversely, the shunt value can be increased for
smaller currents.
CAUTION
Board-mounted current shunt resistors can be installed only for channels 1
and 11. A channel that has been modified with a current shunt resistor
should not be used for voltage or resistance measurements.
shows the locations for the user-installable current shunts. Location R103 is for
R104 (Channel 1 Shunt)
Do not exceed the maximum card signal levels:
• DC signals: 60V DC, 0.5A switched, 30VA maximum.
• AC signals: 30V AC, 0.5A switched, 15VA maximum.
Card Connections and Installation 2-11