KEITHLEY 2182A (01) PDF Document

Before performing verification tests on your KEITHLEY 2182A, ensure the following requirements are met:

Environmental Conditions:

• Conduct tests in an ambient temperature of 18-28°C (65-82°F).

• Maintain a relative humidity of less than 70% unless otherwise noted.

Warm-up Period:

• Allow the KEITHLEY 2182A to warm up for at least 2-1/2 hours.

• If the instrument has been in extreme temperatures, allow an extra hour for every 10°C (18°F) outside the specified range for stabilization.

• Allow all test equipment to warm up for the time specified by its manufacturer.

Line Power:

• The KEITHLEY 2182A requires a nominal line voltage of 100, 120, 220, or 240V at a frequency of 50 to 60Hz or 400Hz. Ensure the correct line voltage is set.

The following equipment is recommended for verifying the performance of the KEITHLEY 2182A. Alternate equipment can be used if its specifications are at least four times better.

*DC calibrator specifications shown include total 90-day 23°C ±5°C uncertainty at specified output. Model 262 error includes a short-term transfer error of ±5ppm at 23°C ±1°C. Digital multimeter specification is 90-day, 23°C ±5°C full-range value.

Restoring Factory Defaults:

1. Press SETUP RESTR. The instrument will display the prompt: RESTORE: FACT

2. Using either RANGE key, select FACT, then restore the factory default conditions by pressing ENTER.

Auto-calibration (ACAL):

1. Disconnect the test cable from the input jack.

2. Turn on the instrument power, and allow the unit to warm up for at least 2-1/2 hours.

3. Press the ACAL key. The instrument will prompt you as follows: ACAL: LOW-LVL

4. Using either RANGE key, select FULL, then press ENTER. The unit will then remind you to disconnect the input cable: REMOVE INPUT

5. Make sure the input cable is disconnected, then press ENTER. The unit will then perform auto-calibration, a process that will take several minutes to complete.

When performing verification procedures, consider the following:

• Be sure to restore factory front panel defaults and perform a full auto-calibration (ACAL).

• Make sure that the KEITHLEY 2182A and test equipment are properly warmed up and connected correctly.

• Be sure the test equipment is set up for the proper function and range.

• Allow the test signal to settle before making a measurement.

• Use only copper-to-copper connections to minimize thermal EMFs.

• Ensure all connections are clean and free of oxidation.

• Keep test connections and all equipment away from drafts to avoid thermal drift.

• Do not connect test equipment to the KEITHLEY 2182A through a scanner, multiplexer, or other switching equipment.

• Do not use autoranging because autorange hysteresis may cause the instrument to be on an incorrect range.

1. With the power off, connect the DC calibrator to CHANNEL 1 of the KEITHLEY 2182A input jack using a Model 2107 Low Thermal Input Cable. The wire colors are Red for Channel 1 HI and Black for Channel 1 LO.

2. Turn on the power, and allow a 2-1/2 hour warm-up period.

3. Restore factory defaults, and do a full auto-calibration.

4. Select the Model 2182 DCV1 measurement function, and select the 100mV range.

5. Set the calibrator output to 0.00000mV, and allow the reading to settle.

6. Enable REL, and leave it enabled for the remainder of the tests.

7. Verify reading accuracy for each of the voltages listed in the table below. For each test point: Select the correct measurement range, set the DC calibrator to the indicated value, and verify the reading is within the limits.

8. Repeat step 7 for negative source voltages with the same magnitudes.

9. Repeat steps 4 through 8 for the 100mV-10V ranges of the CHANNEL 2 input. For Channel 2, use Green for HI and White for LO, and select the DCV2 measurement function.

*Channel 1 only.

1. With the power off, connect the DC calibrator and a low-thermal divider to the CHANNEL 1 terminals of the KEITHLEY 2182A input jack.

2. Turn on the power, and allow a 2-1/2 hour warm-up period.

3. Select the DCV1 measurement function and choose the 10mV range.

4. Select the 100:1 divider ratio.

5. Set the calibrator output to 0.00000V, and allow the reading to settle.

6. Enable REL.

7. Set the DC calibrator output voltage to 1.000000V.

8. Verify the voltage reading accuracy for the 10mV range. The calibrator setting of 10.00000mV (using the 100:1 divider and 1.000000V calibrator output) should result in a reading between 9.99460 to 10.00054mV.

9. Repeat steps 7 and 8 for a negative 10mV source by setting the calibrator voltage to –1.00000V.

1. With the power off, connect a temperature calibrator to the KEITHLEY 2182A CHANNEL 1 input jack. Connect the free ends of the thermocouple wire to the Model 2107 cable lugs, observing proper polarity (+ to HI; – to LO). Place the connections in a 0°C ice bath.

2. Turn on the power, and allow a 2-1/2 hour warm-up period.

3. Press SHIFT then TCOUPL. Use the RANGE and arrow keys to select the following: UNITS: C, JUNC: SIM (set to 0°C), TYPE: J, SENS: TCOUPLE.

4. Select the TEMP 1 function.

5. Verify temperature measurement accuracy for each setting in the table below by setting the KEITHLEY 2182A and the calibrator to the appropriate thermocouple type and temperature, then check that the reading is within the specified limits.

1. With the power off, connect the KEITHLEY 2182A CHANNEL 1 input to a DC voltage calibrator, and connect the rear panel ANALOG output jack to a digital multimeter.

2. Select the DCV1 measurement function and choose the 10V range.

3. Press SHIFT then AOUT. Use the RANGE and arrow keys to set the following: STATE: ON, M: +1.0000000, B: +00.000000.

4. Set the calibrator voltage to 0.00000V, then enable the REL mode on both the KEITHLEY 2182A and the digital multimeter.

5. Verify analog output accuracy for each voltage listed in the table below. For each test point, set the DC calibrator to the indicated voltage and verify the digital multimeter reading is within the specified limits.

Accessing the Calibration Menu:

To access the calibration menu, press SHIFT then CAL. Use the RANGE and left/right arrow keys to scroll through selections. Use the ENTER key to choose menu items and the EXIT key to cancel.

Entering the Front Panel Code:

1. Access the calibration menu by pressing SHIFT CAL.

2. Use the up or down RANGE key to scroll to CAL: RUN, then press ENTER.

3. The unit will prompt for a code: CODE? 000000. The factory default code is 002182.

4. Use the left and right arrow keys to move between digits. Use the up RANGE key to increment numbers and the down RANGE key for letters. Press ENTER to confirm the code.

5. When prompted NEW CODE? N, choose N if you do not want to change the code. Choose Y to enter a new code.

If you lose the calibration code, you can unlock calibration by shorting together the CAL pads, which are located on the display board. This will also reset the password to the factory default (KI002182). Disassembly is required to access the CAL pads.

Preparing for Calibration:

1. Turn on the KEITHLEY 2182A and let it warm up for at least 2-1/2 hours.

2. Start the calibration process by pressing SHIFT then CAL. Scroll to RUN and press ENTER. Enter the calibration code (default is 002182) and choose not to change the code.

Front Panel Short and Open Calibration:

1. At the FRONT SHORT prompt, connect a Model 2188 low-thermal shorting plug to the front panel input jack. Wait at least three minutes for thermal equilibrium.

2. Press ENTER to start short-circuit calibration. The display will show CALIBRATING.

3. When the unit displays REMOVE INPUT, remove the shorting plug and press ENTER. The CALIBRATING message will be displayed again.

DC Volts Calibration:

1. After the short/open procedure, the unit will prompt for the first DC voltage: 10.000000 V.

2. Connect a DC calibrator to the CHANNEL 1 input. Wait two minutes for thermal equilibrium.

3. Set the calibrator to output DC volts with external sense off.

4. For each step in the table below, set the calibrator to the indicated value, wait for it to settle, and press ENTER.

*Use indicated values when possible.

Setting Dates and Saving Calibration:

1. At the end of the procedure, CALIBRATION COMPLETE will be displayed. Press ENTER.

2. At the CAL DATE prompt, set the calibration date and press ENTER.

3. At the CAL NDUE prompt, set the next calibration due date and press ENTER.

4. At the SAVE CAL? YES prompt, press ENTER to save the new constants. Choosing NO will retain the previous calibration.

Preparing for Calibration:

1. Connect the KEITHLEY 2182A to a computer via IEEE-488 or RS-232.

2. Turn on the instrument and allow it to warm up for 2-1/2 hours.

3. Select the DCV1 function and ensure the GPIB address is correct.

4. Unlock calibration by sending: `:CAL:PROT:CODE ‘KI002182’` (use correct code if changed).

5. Initiate calibration by sending: `:CAL:PROT:INIT`

Short and Open Calibration:

1. Connect a Model 2188 low-thermal shorting plug to the input jack and wait two minutes.

2. Send the command: `:CAL:PROT:DC:STEP1`

3. After the step completes, remove the shorting plug and send: `:CAL:PROT:DC:STEP2`

DC Volts Calibration:

1. Connect a calibrator to the CHANNEL 1 input and allow two minutes for thermal equilibrium.

2. Perform the calibration steps summarized in the table below. For each step, set the calibrator voltage, allow it to settle, and send the indicated command.

*Change parameter if using a different calibration voltage.

Programming Dates and Saving:

1. Program dates using commands like: `:CAL:PROT:DATE 2024, 1, 15` and `:CAL:PROT:NDUE 2025, 1, 15`

2. Save the calibration constants: `:CAL:PROT:SAVE`

3. Lock out calibration: `:CAL:PROT:LOCK`

Factory calibration is normally performed only at the factory but is necessary if the unit has been repaired (e.g., internal components changed) or if a +516, “Linearity Precal Lost” error occurs.

Preparing for Factory Calibration:

1. Connect the KEITHLEY 2182A to a computer.

2. Press and hold the STEP key while turning on the instrument. Allow 2-1/2 hours for warm-up.

3. Select the DCV1 function and verify the GPIB address.

4. Unlock the function by sending: `:DIAG:KEIT:CAL:UNLOCK` and `:CAL:PROT:CODE ‘K1002182’`

5. Initiate calibration: `:CAL:PROT:INIT`

Precalibration:

1. Connect a calibrator to CHANNEL 1 and wait two minutes.

2. Perform the precalibration steps by setting the calibrator and sending the commands from the table below.

Short/Open and DC Volts Calibration: Follow the same procedure as for normal remote calibration.

Analog Output Calibration:

1. Connect the analog output to CHANNEL 1 of the front panel input jack.

2. Send the command: `:CAL:PROT:DC:STEP5`

Programming Dates, Saving, and Locking: Follow the same procedure as for normal remote calibration.

1. Disconnect the line cord from the rear panel and remove all other test leads and cables.

2. Locate the power module adjacent to the AC power receptacle on the rear panel.

3. Carefully pry the locking tab that secures the fuse carrier to the power module.

4. Pull out the fuse carrier and replace the fuse with the correct type specified in the table below.

5. Re-install the fuse carrier.

1. Disconnect the line cord and all test leads and cables from the instrument.

2. Carefully pry the locking tab on the power module and pull out the fuse carrier.

3. Pull the fuse holder from the carrier.

4. If changing to a voltage that requires a different fuse (e.g., from 120V to 240V), replace the fuse with the correct type.

5. Rotate the fuse holder so that the desired line voltage (100V, 120V, 220V, or 240V) is displayed in the small window in the carrier.

6. Install the holder back into the carrier, then install the carrier into the power module, ensuring the locking tab secures it properly.

The KEITHLEY 2182A has two front panel tests: KEY test and DISP test.

KEY test (to check front panel key functionality):

1. Press SHIFT and then TEST to access the self-test options.

2. Use the up or down RANGE key to display “TEST: KEY”.

3. Press ENTER to start the test. When a key is pressed, its label name is displayed. When released, “NO KEY PRESS” is displayed.

4. Pressing EXIT twice will abort the test and return to normal operation.

DISP test (to check the display):

1. Press SHIFT and then TEST.

2. Use the up or down RANGE key to display “TEST: DISP”.

3. Press ENTER to start the test. Press ENTER repeatedly to cycle through four test parts: all annunciators displayed, segments of each digit sequentially displayed, all digits sequentially displayed, and end annunciators sequentially displayed.

4. Press EXIT to abort the test and return to normal operation.

A “No Comm Link” error indicates that the front panel processor has stopped communicating with the main processor, which may be due to a main processor ROM needing to be re-seated.

1. Turn off the power, and disconnect the line cord and all other test leads and cables.

2. Remove the case cover.

3. Locate the two firmware ROMs, U102 and U103, on the motherboard. They are the only ICs in sockets.

4. Carefully and gently push down on each ROM IC to make sure it is properly seated in its socket. Do not push excessively to avoid cracking the motherboard.

5. Connect the line cord and turn on the power. If the problem persists, further troubleshooting is required.

Before beginning, disconnect the line cord and all test cables from the instrument.

1. Remove Handle: Gently pull the handle away from the sides of the case and swing it. To remove it, swing it below the bottom surface until the arrows on the handle and mounting ears line up, then pull the ends of the handle away from the case.

2. Remove Mounting Ears: Remove the screw securing each mounting ear, then pull it down and out.

3. Remove Rear Bezel: Loosen the two captive screws that secure the rear bezel to the chassis and pull the bezel away.

4. Remove Grounding Screws: Remove the two grounding screws located on the bottom of the case at the back.

5. Remove Cover: Grasp the front bezel and carefully slide the chassis forward and out of the metal case cover.

Disconnect the instrument from power lines and remove test leads before proceeding.

1. Remove the case cover as described in the disassembly procedure.

2. Locate EPROMs U102 (EVEN) and U103 (ODD) on the motherboard. These are the only devices in chip carriers (sockets).

3. Using an appropriate chip extractor, remove U102 from its chip carrier.

4. Position the new U102 EPROM on the appropriate chip carrier. Make sure the notched corner of the chip is aligned with the notch in the chip carrier. Ensure you are installing it in the correct EVEN location.

5. With the EPROM properly positioned, push down on the chip until it completely seats into the chip carrier.

6. Repeat steps 3 through 5 for EPROM U103 (ODD).

7. After installation, make sure the instrument powers up normally before replacing the cover.

First, make sure the instrument is disconnected from the power line and other equipment.

1. Remove the cover from the instrument.

2. Locate the resistors (which are actually solder beads) used to select the trigger link lines, located next to the Trigger Link connector on the motherboard. The factory default settings are solder beads at R145 (VMC to line 1) and R142 (EXT TRIG to line 2).

3. To change a trigger link line:

• Use a soldering iron and solder sucker to remove the appropriate solder bead.

• Apply a new solder bead to the appropriate resistor location based on the table below.

• Replace the cover on the instrument.

* Factory default

During reassembly of the KEITHLEY 2182A, connect the power module wires as follows: