Checking the Integrity of a Gamry Cell Cable

Introduction

Of all the components of a Gamry system, the Cell Cable is the one that is constantly being flexed and exposed to corrosive environments. This test may take a couple of minutes, but if it identifies a problem, it will be time well-spent.  If the Cell Cable is determined to be faulty, this can prevent a Potentiostat from a needless trip to Gamry for repair. This presents the rare opportunity to save both time and money...especially for our international users. 

We urge you to consider purchasing a spare Cell Cable.  If you only have one Cell Cable, expect it to fail sooner or later.  Having an inexpensive replacement will avoid any downtime.

Symptoms of Suspect Leads

There are other reasons that you may see these specific symptoms, but here is what you will encounter if the cell cable is damaged:

  1. During the Calibration routine, your Potentiostat passes the early internal adjustment tests, but fails the later "Applied Pstat" or "Applied Gstat" tests. This could be a general cell cable problem.  Make sure the cell cable is firmly connected to the Potentiostat and the leads are correctly attached to the appropriate version of the Universal Dummy Cell.
  2. The Working Sense (blue) and Reference (white) leads are the two inputs to the Potentiostat's electrometer.  The electrometer is the potential-measurement device. If the measurement of Potential (Vm) drifts from the value you requested, the problem may lie with one of these two leads. In particular, if the voltage measurement gets to +/-11 Volts, there is a good chance one of these leads is damaged.  Intentional resistors are installed in both of these leads. Both the Working Sense and Reference leads should measure ~ 260 Ohms.
  3. The Working (green) lead is the electrode that measures the current in the cell. You can suspect this lead is damaged, if your system always measures 0 Amps of current. Measuring 0 Amps doesn't stress the Potentiostat, so you will not see any overloaded data. All displayed points will be blue. The Working Electrode lead should measure 0 Ohms.
  4. The Counter (red) lead is the output of the Control Amplifier. The Control Amplifier is the device that delivers the necessary current to control the cell. If there is a break in the Counter Electrode lead, the Control Amplifier will not be able to control the cell. Your data will be displayed in the Framework with red markers and be accompanied by a "CA OVLD" message. The Counter Electrode Lead should measure 0 Ohms.
  5. Also, the Counter Sense and Ground leads should measure 0 Ohms.

Of course, if you have multiple Cell Cables (for a MultEchem or Multiplexer), substituting a known good Cell Cable is the quickest test.  The following are tests for a broken lead, the more common occurrence.  To test for a lead inadvertently shorted to its neighbor, you can test resistance between each pin surrounding the correct pin and the correct cell lead.  Each surrounding pin should measure infinite resistance.

You will need a digital multimeter capable of measuring resistance (any electronics shop should certainly have one).

The pin number is printed on the black section inside the connector beside the base of the pin. You may need to angle it or use a flashlight to see it. 

Diagnostic Check of a Gamry Series G/PCI4/PC4/ECM8 Cell Cable

NOTE: Working Sense and Reference leads should measure ~260 Ohms. The Working and Counter leads should measure 0 Ohms.

  1. Disconnect the Cell Cable from the back of the PCI4 Potentiostat.
  2. Set the Multimeter to read Resistance in Ohms.
  3. Connect one terminal of the Multimeter to the Working Sense (blue) lead....Connect the other end to Pin # 1. You should measure ~260 Ohms.
  4. Connect one terminal of the Multimeter to the Reference (white) lead....Connect the other end to Pin # 6. You should measure ~260 Ohms.
  5. Connect one terminal of the Multimeter to the Working (green) lead....Connect the other end to Pin # 3. You should measure 0 Ohms.
  6. Connect one terminal of the Multimeter to the Counter (red) lead....Connect the other end to Pin # 9. You should measure 0 Ohms.

A broken cell cable is indicated by a very high (infinite) resistance. This indicates that the cell cable is damaged and needs to be replaced. We do not repair cell cables.

There is a complete description in Table D-1 on Page 6-11 of the manualhttp://www.gamry.com/Support/Manuals/V5/PCI4.pdf, which coordinates the Pin/Lead combinations.


Figure 1. Pins in the Cell Cable for the Series G, PCI4, PC4 Potentiostats, and ECM8 Multiplexer.    

Diagnostic Check of a Gamry Reference 600/Interface 1000 Cell Cable

NOTE: Working Sense and Reference leads should measure ~260 Ohms. The Working and Counter leads should measure 0 Ohms.

  1. Disconnect the Cell Cable from the front of the Reference 600 Potentiostat.
  2. Set the Multimeter to read Resistance in Ohms.
  3. Connect one terminal of the Multimeter to the Working Sense (blue) lead....Connect the other end to Pin # 1. You should measure ~260 Ohms.
  4. Connect one terminal of the Multimeter to the Reference (white) lead....Connect the other end to Pin # 16. You should measure ~260 Ohms.
  5. Connect one terminal of the Multimeter to the Working (green) lead....Connect the other end to Pin # 13. You should measure 0 Ohms.
  6. Connect one terminal of the Multimeter to the Counter (red) lead....Connect the other end to Pin # 23. You should measure 0 Ohms.

The indication of a broken cell cable is that one of these four tests will measure a very high (infinite) resistance. This indicates that the cell cable is damaged and needs to be replaced. We do not repair cell cables.

There is a complete description in Table B-1 on Page 10-1 of the Reference 600 Manual http://www.gamry.com/Support/Manuals/V5/Reference%20600.pdf which coordinates the Pin/Lead combinations.

At the conclusion of this test, you will probably need to contact Gamry -- either to purchase a replacement cell cable or to make arrangements to repair the Potentiostat.


Figure 2. Pins in the Cell Cable for the Reference 600 Potentiostat. 

Diagnostic Check of a Gamry Reference 3000 Cell Cable

NOTE: Working and Counter leads should measure 0 Ohms.

Verifying the Counter/Working Cell Cable

  1. Disconnect the Counter/Working cable from the front of the Reference 3000 Potentiostat.
  2. Set the Multimeter to read Resistance in Ohms.
  3. Connect one terminal of the Multimeter to the Working (green) lead…Connect the other terminal to Pin # 9.  You should measure 0 Ohms.
  4. Connect one terminal of the Multimeter to the Counter (red) lead…Connect the other terminal to Pin # 5.  You should measure 0 Ohms. 

    Continue on to step 5 only if you measure very high or infinite resistance in the preceding steps.

  5. Using a Philips head screwdriver, locate and remove the two screws located on the hood of the D-connector that plugs into the front-panel of the Reference 3000 Potentiostat.  This will give access to the fuses. The fuses are very small (2.5 x 6 mm).
  6. Connect your Multimeter terminals to each side of one fuse to test the Resistance.  Functioning fuses will measure 0 Ohms.  Remove any faulty fuses by using a pair of tweezers, and replace them with spares that were shipped with your Reference 3000 cables.
  7. Reassemble the D-connector and repeat steps 3 and 4 to verify proper continuity throughout the Counter/Working cable. 

The indication of a broken Counter/Working cable is that either the Working or Counter leads will measure a very high (infinite) resistance after the fuses have been checked.  This indicates that the cable is damaged and needs to be replaced.  We do not repair cell cables.

NOTE: Working Sense, Counter Sense, and Reference leads should measure ~260 Ohms.

Verifying the Sense Cable

  1. Disconnect the Sense cable from the front of the Reference 3000 Potentiostat.
  2. Connect one terminal of the Multimeter to the Working Sense (blue) lead…Connect the other terminal to Pin # 8.  You should measure ~260 Ohms.
  3. Connect one terminal of the Multimeter to the Counter Sense (orange) lead…Connect the other terminal to Pin # 11.  You should measure ~260 Ohms.
  4. Connect one terminal of the Multimeter to the Reference (white) lead…Connect the other terminal to Pin # 13.  You should measure ~260 Ohms.

The indication of a broken Sense cable is that any of these three tests will measure a very high (infinite) resistance.  This indicates that the cell cable is damaged and needs to be replaced.  We do not repair cell cables.


Figure 3. Pins in the Sense Cell Cable for the Reference 3000 Potentiostat.