BS ISO 19097-2:2018 pdf download – Accelerated life test method of mixed metal oxide anodes for cathodic protection Part 2: Application in soils and natural waters
4.3.6 A thermometer shall be inserted in the cell. If more than one cell is used, each cell shall have a thermometer installed. The exact type of thermometer used shall be in accordance with the general safety practices of the laboratory and shall not have any materials exposed to the electrolyte that could corrode and contaminate the solution. Alternately, a thermocouple may be used. The temperature range of the thermometer shall be 20 °C to 100 °C. Stainless steel or other metallic thermocouples shall not be exposed to the electrolyte to avoid corrosion and contamination.
4.3.7 The power supply shall be a constant current control, typical for laboratory use. The required amperage shall be determined from the sample size and the current density for the particular accelerated test point. For example, 5 A is appropriate for a 500 mm 2 sample being run at 10 kA/m 2 . One power supply can also energize several electrolytic cells connected in series at the same time. The required voltage depends on the number of test stations in series that may be used. Typically, 8 V per cell times the number of cells in series is sufficient.
4.3.8 Use data acquisition device or voltmeter to monitor the voltage of each cell continuously until the failure of the anode. The voltage measuring device shall have a high input impedance of 10 MΩ or greater, and be capable of measuring cell voltage accurate to ±1 %.
4.3.9 Temperature control equipment may be necessary to maintain the electrolyte within the required range depending on laboratory conditions. Essentially, a fluid may be used to input or extract heat from the electrolyte indirectly. Examples of such equipment are jacketed beakers and water bath for beakers. NOTE A schematic diagram of test apparatus is shown in Annex A.
4.4 Test specimens
4.4.1 The number and type of test specimens shall be selected according to the specifications for the anode material or product being tested. To ensure the accuracy of the data, usually three, but at least two, duplicate specimens of each anode shall be tested in the separate cells under identical operating conditions.
4.4.2 The test specimens shall be carefully cleaned prior to testing so as to remove those traces (dirt, oil or other foreign matter) that could influence the result. Care shall be taken that specimens are not contaminated after cleaning by careless handling.
4.5 Test procedure
4.5.1 The test shall be conducted in a well‑ventilated laboratory fume hood. The gas released from the cell is a potentially explosive mixture of hydrogen and oxygen and shall be well ventilated.
4.5.2 The test cell shall be filled with electrolyte, making sure that the anode sample is completely immersed in the solution, and agitated with a magnetic stirrer or similar means of ensuring good mixing.
4.5.3 Water lost during the test shall be replaced by distilled or deionized water to maintain the electrolyte level ±5 %. At no time shall the level be less than that required to maintain the test equipment setup.
4.5.4 The power supply shall be energized, the current increased to the test setting, and the cell allowed to stabilize for 3 h. Current flow shall be confirmed by the production of gas bubbles at both the anode and the cathode. If the current changes more than 1 % from the set point, then the test shall be stopped and the cause investigated. The test may be continued after appropriate corrective action.
If the cell voltage exceeds the target voltage, then the test shall be paused to allow the removal of the cell from the test station. After removal of the failed cell from the circuit, the test may be started again so that the remaining samples can be tested to completion.BS ISO 19097-2 pdf download.