Keithley SourceMeter 2460 for low resistance device measurement steps

Keithley SourceMeter 2460 has the flexibility to source/sink large currents and measure voltage and current, making it a perfect solution for measuring low-resistance devices (requiring up to 7A excitation current). Previously, Antai Test has shared how to use Keithley Digital SourceMeter 2460 to measure low-resistance devices using large currents. Today, Antai Test will continue to share the steps for measuring low-resistance devices using Keithley SourceMeter 2460:

To make low resistance measurements using the SCPI code or TSP code, use the Model 2460 front panel or remote interface. The steps are as follows:

•Reset the instrument;

•Select to source current and measure resistance;

•Select the source current value;

• Select 4-wire (remote sense) mode. This will eliminate the effects of lead resistance on measurement accuracy.

• Enable bias compensation. This will reduce the bias due to thermoelectric voltages.

• Turn on the source output and start measuring.

• Generate readings through the front panel or remote interface.

• Turn off the source output.

Set up measurements via the front panel

To set up the application via the front panel:

Connect the Model 2460 to the device under test.

1. Reset the instrument:

a. Press the MENU button.

b. Under System, select Manage.

c. Select System Reset.

d. Select OK.

2. Press the FUNCTION button.

3. Under Source and Measure, select Resistance.

4. Press the HOME button.

5. In the SOURCE CURRENT area, select the button next to Source and select the source value.

6. Press the MENU button. Under Measurement, select Settings.

7. Under Sense Mode, select 4-Wire Sense.

8. Next is Offset Compensation, select On.

9. Press the HOME button.

10. Press the OUTPUT ON/OFF switch to enable the output and start measuring.

11. Press the OUTPUT ON/OFF switch to disable the output and stop measuring.

The measurement results are displayed in the MEASURE VOLTAGE area of ​​the instrument screen.

View measurement results, TREND screen and GRAPH full screen through the front panel

The resistance measurement and the current being applied can be viewed on the instrument front panel.

Figure 7: 2460 instrument main screen front panel

The resistance measurement results seen on the TREND swipe screen change over time. To access this screen, swipe the bottom of the main screen and a graph similar to Figure 8 will appear.

Figure 8 TREND screen refresh for 2460 instrument

If you want to view the graph in full screen, you can refresh the screen TREND to open the Graph screen. View the statistics of the buffer through the front panel

The STATISTICS screen on the Model 2460 front panel displays a variety of measurement statistics, including:

• Buffer name

•Minimum, maximum and average readings

•standard deviation

Figure 9 STATISTICS screen of the 2460 instrument

Use SCPI commands to set up low-resistance applications

The following SCPI command sequence can be used to make 100 low resistance measurements by sourcing current and measuring resistance. In this example, the source current amplitude and limit voltage are set automatically. Using remote commands, the front panel display is changed to show the TREND screen, allowing viewing of numeric data at the top of the screen and graphical data at the bottom of the screen.

When running this code in a specific programming environment, some changes may be required. For this example application, send the following command:

Use TSP instruction to set up low impedance application

The following TSP code is designed to run Keithley's Test Script Builder (TSB). TSB is a software tool that can be downloaded free of charge from the Keithley Instruments website. Once installed, TSB can be used to write code and develop scripts for instruments supported by TSP. For information on how to use this tool, see the TSB online help file and the "Introduction to Using the TSP" section of the Model 2460 Reference Manual.

If you use another programming environment, you may need to modify this TSP code example. The default configuration for the Model 2460 is to use the SCPI command set. Always select the TSP command set before sending TSP commands to the instrument. To enable TSP commands:

1. Press the MENU button.

2. Under System, select Settings.

3. For Instruction Set, select TSP.

4. When prompted to reboot, select Yes.

This TSP instruction sequence makes 100 low resistance measurements by sourcing current and measuring resistance. In this example, the source current amplitude and voltage limit are set automatically. The front panel display is changed using remote commands to show the TREND screen. This allows viewing of numerical data at the top of the screen and graphical data at the bottom of the screen. After the code executes, the data is displayed on the dashboard of the Test Script Builder.

For this example application, send the following command: -- Reset the instrument to default settings reset()

—— Configure the simple loop trigger model template,

Take 100 readings

trigger.model.load("SimpleLoop", 100)

—— Change the front panel display to TREND screen refresh display.changescreen(display.SCREEN_PLOT_SWIPE)

—— Set up the measurement resistance, using 4-wire sensing and offset compensation

—— and bias compensation smu.measure.func = smu.FUNC_RESISTANCE

smu.measure.sense=smu.SENSE_4WIRE

smu.measure.offsetcompensation = smu.ON—— Turn on output smu.source.output = smu.ON

-- Start the trigger model and wait until it completes.

trigger.model.initiate()

waitcomplete()

—— Turn off output

smu.source.output = smu.OFF

—— Read resistance and time values ​​from defbuffer1

print("Resistance:tTime:")

for i = 1, 100 do

print(string.format("%ft%f", defbuffer1[i], defbuffer1.relativetimestamps[i]))

The Keithley SourceMeter 2460 is ideal for characterizing high current, low resistance devices and components because of its 4-quadrant design, high power output, and ability to accurately measure both current and voltage. Using a single instrument for these tests simplifies test setup, reduces programming time, and saves rack space.