Pre-test preparation

The goal of this stage is to ensure that all conditions are consistent and reproducible.

• Working electrode (sample) processingThis isthe most crucialOne of the steps. Before testing, consistent pre-treatment of the sample surface is required, such as grinding, polishing, cleaning, and dehydration. Special attention should be paidFingers cannot directly touch the effective testing area of the substrateBecause grease and sweat stains on the hands may cause localized blistering or rusting of the coating-.

• Sample packagingThe sample must be firmly encapsulated on the electrode holder, ensuring that only the testing surface is exposed to the solution. The back and sides need to be strictly sealed with insulation materials such as epoxy resin.Any small leak can result in inaccurate testing area and cause severe localized corrosion, rendering data invalid.

• Solution preparation and environmental controlAccurately prepare the solution using high-purity water and measure and record its composition and pH value. According to the testing purpose, to study the anodic behavior of metals, high-purity nitrogen or argon gas must be introduced for at least 30 minutesRemove dissolved oxygen from the solutionMeanwhile, use a constant temperature water bath to maintain a constant temperature of the solution.

• Electrode inspectionEnsure that the reference electrode liquid interface is unobstructed and the internal filling is sufficient. The electrode (such as platinum plate) should be clean, and its area should preferably be much larger than the working electrode to ensure uniform current distribution.

Test process control

The correct operation is the foundation for obtaining reliable data.

• Correct connection and placementCorrectly connect each electrode to the corresponding port of the electrochemical workstation (working electrode WE, counter electrode CE, reference electrode RE), and misconnection is a common error. The Lujin capillary opening of the reference electrode shouldVery closeThe surface of the working electrode (usually 1-2 times the diameter distance) is used to reduce measurement errors.

• Waiting for the system to stabilizeAfter connecting the system,Do not start testing immediatelyThe open circuit potential of the working electrode should be monitored first. When its rate of change is less than 1 mV/min and maintained for 10-15 minutes, it indicates that the system has reached a stable state. At this point, formal testing can begin-.

• Parameter Setting and SecurityReasonably set parameters such as scanning rate according to the experimental purpose, as too fast a scanning rate may cause data distortion. If the test solution is toxic or corrosive, it must be operated in a fume hood and ensure that there is no direct contact between all electrodes.

Cleaning and maintenance after testing

Good maintenance habits can extend the lifespan of equipment and ensure the accuracy of the next test.

• Timely cleaningAfter the test is completed,immediatelyDisassemble and rinse the test cell and all electrodes with a suitable solvent (such as deionized water) to prevent corrosive solutions or crystals from damaging the equipment.

• Electrode maintenance：

• reference electrodeStore vertically in a dedicated filling solution as required,Never let the liquid interface dry upWhen not in use for a long time, a protective cap should be worn.

• counter electrodeFor platinum electrodes, they should be cleaned thoroughly and stored in a dry state.

• working electrodeAfter cleaning and drying, store it properly for analysis.

• Detailed recordsBe sure to record all experimental conditions in detail, including solution composition pH、 Temperature, ventilation status, electrode area, reference electrode type, stable open circuit potential value, etc. These pieces of information are crucial for subsequent analysis, interpretation, and experimental reproducibility of the data.

Important tips for other testing methods

If your 'testing pool' refers to an environmental testing chamber such as a salt spray test, the following points are equally crucial:

• Sample edge protectionPrepared test samples,Need to use paint to seal the edges and exposed areas of the substrateOtherwise, rust marks will accumulate and contaminate the test surface, interfering with the rating.

• Scratch makingIf scratches need to be made, they shouldOne time scratch through the coating to expose the substrateTo avoid coating flipping caused by repeated cutting. Scratches should be more than 20mm away from the edge of the template.

• Inspection and ratingWhen regularly inspecting the sample, try to keep the board surface moist and shorten the exposure time to the air. After the experiment is completed, an objective rating should be conducted immediately.

In summary, to obtain accurate and reliable coating evaluation data, you need to prepare thoroughly, operate in a standardized manner, keep detailed records, and maintain them in place at every stage, just like in precision experiments.