Approved test instruments

The test instruments and test leads used by the electrician for testing an electrical installation must meet all the requirements of the relevant regulations. The HSE has published guidance note GS 38 for test equipment used by electricians. The IET Regulations (BS 7671) also specify the test voltage or current required to carry out particular tests satisfactorily. All test equipment must be chosen to comply with the relevant parts of BS EN 61557. All testing must, therefore, be carried out using an approved test instrument if the test results are to be valid. The test instrument must also carry a calibration certificate, otherwise the recorded results may be void. Calibration certificates usually last for a year. Test instruments must, therefore, be tested and recalibrated each year by an approved supplier. This will maintain the accuracy of the instrument to an acceptable level, usually within 2% of the true value. 

Modern digital test instruments are reasonably robust, but to maintain them in good working order they must be treated with care. An approved test instrument costs as much as a good-quality camera it should, therefore, receive the same care and consideration. 

If you purchase good-quality approved test instruments and leads from specialist manufacturers they will meet all the regulations and standards and therefore give valid test results. However, to carry out all the tests required by the lET Regulations will require a number of test instruments and this will represent a major capital investment in the region of 1,000. 

State three reasons why electricians must only use approved test instruments. 

The test instruments and test /eads used by the electrician for testing an electrical installation must meet all the requirements of the relevant regulations. All testing must, therefore, be carried out using an approved test instrument if the test results are to be valid. The test instrument must also carry a calibration certificate othenvise the recorded results may be void. 

ASME PTC 50 ASME Performance Test Code 50 - Fuel Cell Power Systems provides test procedures, methods and definitions for the performance characterization of fuel cell power systems. The code specifies the methods and procedures for conducting and reporting fuel cell system ratings. Specific methods of testing, instrumentation, techniques, calculations and reporting are presented. This standard is currently being drafted and is expected to be approved and published in 2002. 

Therefore, the first area of investigation is to determine the compliance of an instrument performance with the technical specification of the manufacturer and the standard requirements within pattern approval tests. For this purpose, a metrological procedure is is-... 

Calibration certificates usually last for a year. Test instruments must, therefore, be tested and recalibrated each year by an approved supplier. 

The procedure approved by Gosstandart may have status of state standard, for example, GOST Non-destructive Testing. Ultrasonic Testing of rails , where types of devices, probes, procedure of the instrument adjustment are specified. Such kind of procedure may be used on site. 

Instrument qualification is required to establish the functional capability and reliability of a system for its intended use in a suitable environment. Instrument qualification can be divided into three stages installation, operation, and performance qualifications. A qualification protocol that provides details about the system, the scope and constraints of the qualification, qualification tests, test procedures, and acceptance criteria should be available for review and approval before qualification begins. Sufficient time should be provided for review and approval. The protocol should also contain an exception log to record any out-of-specification results, investigation, and problem resolution. 

After the qualification testing, a summary report should be written to summarize validation activities with a conclusion as to whether the instrument is suitable to be put into routine use. The report should highlight the objective and scope of the validation project, all the qualification test results, test exceptions, and a recommendation for system acceptance. All the test procedures, test results, and the summary report must be reviewed and approved by quality assurance and/or management before product use. 

For the control/monitoring instrumentation, regulating devices, and any associated electrical equipment, predelivery testing and calibration is normally the responsibility of the instrument/equipment manufacturer and should be carried out to approved written procedures using calibration test equipment that is traceable back to agreed-upon national standards. The test equipment must have precision, accuracy, and repeatability that are higher than that of the instrument being calibrated. 

Calibration of the instrumentation will be performed over the complete instrument loop. During each loop calibration, all data must be documented on appropriate instrument and loop calibration sheets and submitted to the pharmaceutical manufacturer for review, approval, and record. Calibration test equipment must be traceable back to agreed-upon national standards and documented on each calibration result sheet. 

The calibration test sheets form the evidence necessary to demonstrate the accuracy of data gathered during product manufacture and as such are key inspection documents. Critical instruments must be provided with a calibration test sheet/certificate that details both the test results and their limits of uncertainty. Calibration test sheets must be checked and approved by an authorized person. 

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