Listed below in tabular and prose format are some common problems associated with running the CHN Analyzer. As difficulties are encountered, one may also refer to the Perkin Elmer manual. Error messages and their associated numbers are listed there in the 'Messages' section.

Some examples:
If the N value of your samples is increasing with each run, the Reduction Tube is spent and needs to be replaced.

The machine will also print out a reminder when it is time to change either tube or empty the vial receptacle. You can also check the run counters by pressing Parameters 4 to see how many more analyzed samples will fit in the vial receptacle before you have to empty and clean it.
*See Replacing the CHN Tubes.

After changing the tubes, run Leak Tests.
If they fail, there could be a faulty o-ring that needs replacing and the machine will print out a message if that is the case.
O-rings are located above and below the tubes inside the machine - replacements are in the CHN supply drawer.
*See Replacing the CHN Tubes.

Message 10 means the Hydrogen K-Factor is out of tolerance and can most likely be ignored since we do not use the Hydrogen value - press Start and the run sequence will continue.

If, for any reason, you must stop the run sequence, press Single Run and the machine will finish analyzing the present sample and then go into STANDBY.
*Make sure you remove the sample from the drop hole using the micro forceps and place it back in your capsule tray.
If you remove samples, make sure you keep them in the same order so you don't get confused - keep all samples in a desiccated environment while not in use.

Sometimes the analyzer will not drop a sample or it will analyze two samples at once. If this happens, push SINGLE RUN to stop the machine and remove the sample from the drop hole.

K-factor Problems:

If you need to calibrate the machine by running multiple K-factors using the Single Run mode, you can unscrew the autosampler and remove it from the machine in order to manually move the wheel back the number of spaces you require. You can analyze a couple of Single Runs of K-factors to recalibrate the machine until the values are within the limits.

K-factor limits are listed in the table in the CHN Standards section. If, after analyzing a K-factor in your Auto Run, the values are more than +/- 10% of the limit listed, you'll need to stop the run and analyze K-factors until the levels are within the limit.

Once the K-factor values are within the limit, move the wheel back to the next run number in your sequence, use the micro forceps to add the next sample to the drop hole, and press START to resume the Auto Run.