Tekmar Talk Blog

Preventive maintenance for analytical instrumentation should be scheduled and performed proactively. It is something that should not be put on the back burner. Establishing and adhering to a preventive maintenance schedule is beneficial in many ways:

• Reduces the risk of instrument failure
• Decreases unexpected downtime
• Increases laboratory productivity
• Extends instrumentation lifetime
• Saves money

Having worked in several laboratory settings, I can verify that one of the worst situations that will occur is instrument failure. One of the main things that would determine a good day from a bad day would be the presence or absence of the sound of laboratory equipment failure beepers upon arriving to the lab each morning.

✔️No beeper sound = good

❗  Beeper sound = bad

❌ Multiple beeper sounds = very bad!

Obviously, waiting or forgetting to perform scheduled preventive maintenance puts your lab at risk for instrument failure and thereby lost productivity and possibly a damaged reputation. Sometimes preventing failures can be as simple as checking for adequate gas, water, and reagent supplies to complete an analysis schedule.

Laboratory instrumentation should not be problematic to maintain. Teledyne Tekmar offers three analyzers for total organic carbon (TOC) analysis that are simple to maintain by design.

• Fusion – UV/Persulfate TOC Analyzer
• Torch – High-Temperature Combustion TOC Analyzer
• Lotix – High-Temperature Combustion TOC Analyzer

While these instruments are easy to maintain, the high-temperature combustion analyzers require more maintenance due to the catalytic conversion of carbon to CO₂ that occurs inside the quartz combustion tube. The following checklists outline the maintenance required for successful operation of these TOC analyzers.

Daily Maintenance Checks

• Gas Supply – Verify the gas source is supplying the proper input pressure required of your instrument. If using a gas cylinder, verify there is enough gas to complete the scheduled analysis.
• Reagent Water Supply – For the Fusion and Torch, replace the reagent water with fresh reagent water daily and ensure there is enough to complete the scheduled analysis. For the Lotix, the reagent water is in a pressurized vessel and only needs to be replenished when the level gets low.
• Acid Supply – Verify there is enough acid available for the scheduled sample analysis and that the acid supply is less than one month old.
• Sodium Persulfate (Na₂S₂O₈) Supply (Fusion) – Verify there is enough sodium persulfate available for the scheduled analysis and that the sodium persulfate supply is less than one month old.
• Gaseous Sample Flow Pathway – For Fusion and Torch, ensure instrument passes leak check diagnostic test. For the Lotix, ensure there is minimum flow loss from the furnace to the vent line out of the detector.
• Monitor results for cleaning procedure and sample blanks. When these results start to drift higher than normal, it is an indication of possible contamination or the need to replace the catalyst and combustion tube.

Weekly Maintenance Checks 

• Seven-port valve (Fusion and Torch) – Make sure the two screws that attach the seven-port valve to the syringe pumper are tight.
• Halogen Scrubber – Check the copper side of the scrubber. When the copper is almost completely discolored, replace the copper, tin, and glass wool with new copper, tin, and glass wool. Failure to maintain the scrubber can lead to costly internal damage to the detector.

Monthly Maintenance Checks  

• Instrument Glassware – Inspect instrument glassware for cleanliness. Clean as required. Cleaning of glassware is typically sample type dependent. Monitoring system blanks and reproducibility will help determine if any cleaning needs to occur. This also applies to sampling and injection lines.
• Inspect Combustion Tube/Catalyst/Injection Needle/Quartz Wool (Torch and Lotix) – Maintenance for these items is greatly affected by sample type and number of samples analyzed. A good way to monitor combustion tube maintenance is by tracking absorbance readings for calibration standards and instrument reproducibility. As the need to replace parts becomes apparent, sensitivity will be reduced and reproducibility will become inadequate.
• Perform Benchmark diagnostics test. This will test all parts of the instrument to ensure it is in good working condition.

While these checklists are not exhaustive, a detailed section in each instrument’s manual is dedicated to maintenance and troubleshooting.

Another great way to maintain analytical excellence with your Teledyne Tekmar TOC analyzer is to contact our Customer Support Center and ask about scheduled maintenance service provided by our certified Service Engineers (TekmarSupport@Teledyne.com).

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