Current Measurements; Figure 2-8 Current Shunt Locations - Keithley 2000-Scan Instruction Manual

2-12 Card Connections and Installation

Current measurements

Current shunts can be installed on the circuit board to allow indirect AC and DC current
measurements to be made through channels 1 and 6 only. The following paragraphs discuss
installing current shunts and the basic methods used to determine currents.
CAUTION
Current shunt locations
Figure 2-8
channel 1 and R146 is for channel 6.
Figure 2-8
Current shunt locations
Recommended current shunt values
Hole spacing on the circuit board is intended for 1/4W resistors. The resistance value will
depend on the current you intend to measure; 1kΩ resistors should be optimum for many
applications. A 1kΩ resistor will allow you to switch currents up to 15mA 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 6. 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 R145 is for
R145 (Channel 1 shunt)
CH 1 CH 2 CH 3 CH 4
H L H L H L H L
Do not exceed the maximum card signal levels:
• DC signals: 110V DC, 1A switched, 30 VA maximum.
• AC signals: 125V AC rms or 175V AC peak, 1A switched, 62.5 VA
maximum.
R146 (Channel 6 shunt)
CH 5 OUT A CH 6
CH 7 CH 8 CH 9
H L H L H L H L H L H L
CH 10 OUT B
H L H L