The standard GB 10127-88 ”Test Method for Stainless Steel Cathodic Rectifiers of Corrosion Gaps” is a widely used standard for testing corrosion gaps in stainless steel trichloride baths. Corrosion gaps occur as a result of biofilm buildup on the surface of stainless steel trichloride baths. This biofilm comprises organic matter, minerals, and other debris, which can corrode the surface of the bath. As such, testing of the corrosion gap is required to ensure that the bath is in good condition, and that its performance is sufficient to meet the safety standards set forth in the standard.
The test method provided in the standard is quite straightforward. A clean, stainless steel trichloride bath is first filled until the water is reaching a height of a few millimeters below the edge of the bath. Then, a pair of test probes is dipped into the water: one probe is connected to a current source and the other is connected to a readout device. The current source is then used to introduce a prescribed current into the system, which in turn conveys a small electric current through the gap between the two probes. The readout device is then capable of measuring the amount of current that was lost across the gap during the test.
The standard then goes on to set forth specific criteria for the tests. For instance, the current source should not provide a current that exceeds 0.01 volts and the readout device should measure up to a maximum of 10 microamperes. After the tests have been conducted, the results should generally indicate that the gap in the stainless steel trichloride bath is not greater than 0.05mm. Any gap beyond this amount requires that further investigation be conducted, and that remedial measures be taken if necessary. This could include the use of cleaning agents, surface treatments, or both, in order to ensure that the bath remains in a safe, usable condition.
The aforementioned standard is, of course, just one example of the many standards that are applied internationally to ensure the safety of all types of baths. However, the specific test method described herein is a rather simple procedure that would typically be repeated in a laboratory setting in order to assess the performance and suitability of a stainless steel trichloride bath, and thus should be actively employed by all health and safety representatives in order to keep baths in pristine condition.
