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SummaryIn this study, the implementation of the ISO/IEC 17025 standard in a Transformer Oil Testing Laboratory (TOTL) for performing the Electrical Breakdown Voltage was evaluated. The application of such a QA system involves a great deal of human resources, top management commitment, organizational effort, expertise and expense. Three years of experience of working under the ISO/IEC 17025 compliant quality system is described. The enhanced reliability of the test results, the technical competence of TOTL staff, the increased trust and satisfaction of established customers and the improved reputation of the TOTL are important gains that are attained from the application of the ISO/IEC 17025 standard. Conversely, the drawbacks that resulted from implementing and maintaining the ISO/IEC 17025 QA system were enormous costs, time-consuming efforts, and increased documentation of test procedures. In addition, no new customers or contracts were generated as had been expected. Therefore, the author does not recommend that laboratories pursue ISO/IEC 17025 accreditation unless the requirement is necessitated by customer needs and only when the test for accreditation is entirely appropriate. Moreover, significant benefits covering the costs of establishing, implementation, accreditation and maintaining of this standard should be identified.

Purpose -The purpose of this paper is to carry out laboratory studies of the inhibition effect of tyrosine (Tyr) on the corrosion of low chromium alloy steel (ASTM A213 grade T22) in 7 wt percent sulfamic acid solutions. Design/methodology/approach -The corrosion inhibitive effect of Tyr was investigated using electrochemical impedance spectroscopy (EIS) and the new technique electrochemical frequency modulation (EFM). Findings -It was found that the inhibition efficiency increased with increasing inhibitor concentration, while a decrease was detected with the rise of temperature and stirring speed. The corrosion inhibition is due to physical adsorption of Tyr on the steel surface. Adsorption of the inhibitor molecule, onto the steel surface follows the Temkin's adsorption isotherm. Originality/value -The obtained results from both methods (EIS and EFM) at different experimental conditions were in high agreement and almost similar. This is an indication that the EFM technique can be used efficiently for monitoring the corrosion inhibition under the studied conditions.