The text of the International Standard IEC was approved by ISO/ IEC Guide Uncertainty of measurement -. Find the most up-to-date version of IEC at Engineering also reflected by the older editions of the relevant standard IEC For good practice in HV test fields, this Sect. on HV measurement and uncertainty .
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Search the history of over billion web pages on the Internet. High – Voltage Test Techniques, Part 2: Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of iiec Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.
The text of lEC Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following: In this adopted standard, reference appears to certain International Standards for which Indian Standards also exist. The corresponding Indian Standards which are to be substituted in their respective places are listed below along with their degree of equivalence for 6006-2 editions indicated: General definitions and test requirements lEC Instruments ie software used for measurement in high-voltage impulse tests — Part 1: Requirements for instruments lEC Instruments and software used for measurement in high-voltage impulse tests — Part 2: Part 1 General definitions and test requirements second revision IS 1 Part 1: Part 1 Requirements for instruments IS 1 Part 2: Part 2 Evaluation of software iiec for the determination of the parameters of impulse waveforms Degree of Equivalence Identical to lEC Ic to the expression of uncertainty in measurements GUM Only the English language text in the International Standard has been retained while adopting it in this Indian Standard, and as such the page numbers given here are not the same as in the lEC Publication.
For measurements during on-site tests see lEC The limits on uncertainties of measurements stated in this standard apply to test levels stated in lEC The principles of this standard apply eic to higher levels but the uncertainty may be greater.
For dated references, only the edition cited applies. For 60060-2 references, the latest edition of the referenced document including any amendments applies. General definitions and test requirements lECInstruments and software used for measurement in high-voltage impulse tests – Part 1: Requirements for instruments lECDigital recorders for measurement in high-voltage impulse tests – Part 2: Measuring systems which comprise only some of the above components or which are based on non-conventional principles are acceptable if they meet the uncertainty requirements specified lec this document.
NOTE 2 The environment in which a measuring system functions, its clearances to live and earthed structures and the presence of electric or magnetic fields may significantly affect the measurement result and iiec uncertainty. The device is designated by the type and arrangement of its elements for example, resistive, capacitive or resistive-capacitive.
For example, an optical link includes a transmitter, an optical cable irc a receiver as well as related amplifiers. NOTE 2 A transmission system may be partially or completely included in the converting device or in the measuring instrument.
NOTE 2 For measuring systems that display the value of the input quantity directly, the nominal scale factor of the measuring eic is unity. Idc 2 A measuring system can have more than one assigned measurement range with different scale factors. Curve B sfiows a constant response down to direct voltage.
For example, a particular measuring system might be approved: This is to be distinguished from a “tail-chopped impulse” which has a time to chopping greater than the time of the extreme value. The permissible deviation should be related to acceptable uncertainties of a measuring system.
NOTE 2 The measured test voltage is required to lie within the stated tolerance of the specified test level. NOTE 2 Uncertainty of voltage measurement should not be confused with the tolerance of a specified test voltage. NOTE 2 In some cases, the relative standard uncertainty of a measurement may be appropriate.
The relative standard uncertainty of measurement is the standard uncertainty divided by the measurand, and is therefore dimensionless. In impulse voltage measurements they are usually taken from step response measurements Annex C.
The initial tests consist of type tests performed on a component or system of the same design and routine tests performed on every component or system. The system is approved only for the arrangements and operating conditions included in its record of performance. A major requirement for a converting device, a transmission system, and a measuring instrument used in a measuring system is stability within the specified range of operating conditions so that the scale factor of the measuring system remains constant over long periods.
The assigned scale factor is determined in the performance test by calibration. The user shall apply tests given in this standard to qualify their measuring system s. Alternatively, any user may choose to have the performance tests made by a National IVIetrology Institute or by a Calibration Laboratory accredited for the quantity to be calibrated.
In all cases, the user siiall include the test data into the record of performance. The user shall ensure that any self-made calibration is performed by competent personnel using reference measuring systems and suitable procedures. The interval between performance tests shall be based on evaluation of past stability of the measuring system.
It is recommended that the performance test should be repeated annually, but the maximum interval shall not be longer than five years. NOTE Long intervals between performance tests can increase the risk of an undetected change in the measurement 60060-2.
Performance test shall be made after major repairs to the measuring system and whenever a circuit arrangement that is beyond the limits given in the record of performance is to be used. The interval from the last performance test or the last performance check shall not be ief than one year.
For a new or repaired measuring system, performance checks shall be made at short intervals to demonstrate its ief. No reference method is identified for the performance checks because the required accuracy is less than that required for performance tests. The record of performance shall uniquely identify the components of the measuring system and shall be structured so that iev of the measuring system can be traced over time.
The record of performance shall comprise at least the following information: For many measuring systems, information on the transmission system as well as high-voltage and ground-return arrangements are important. Then performance tests and checks made in accordance with earlier versions of this standard are deemed adequate provided they show the scale factor is stable.
Approved measuring systems comprising several pieces of equipment used inter-changeably may be covered by a single record of performance including all the combinations possible with the least amount of duplication possible. Specifically, each converting device shall be covered individually, but transmission systems and measuring instruments may be covered generically.
The parasitic coupling between the test and measuring circuit should be minimized. NOTE 1 Parasitic coupling may need to be investigated. An approved measuring system shall have an uncertainty within the specifications of this standard throughout the ranges of operating and environmental conditions given in the record of performance. The assigned operating time for measuring systems for direct and alternating voltage shall be specified.
NOTE 2 The recommended minimum value for the assigned operating time is 1 h. The maximum rate of application for impulse voltages shall be specified.
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The range of environmental conditions, under which the components of the measuring system fulfil the requirements of this standard, shall be stated. These simplified procedures of clause 5 are considered sufficient for the instrumentation and measurement arrangements commonly used in high-voltage testing: In general, the measurand to be considered is the scale factor of the measuring system, but in some cases other 6060-2, such as the time parameters of an impulse voltage and their associated ie, should 60060-2 be considered.
NOTE 1 Other measurands for specific converting devices are in common use. For example, a voltage divider is characterized by the voltage ratio and its uncertainty in the assigned measurement ranges used.
A voltage transformer is characterized by the ratio error, the phase displacement and the corresponding uncertainties. For example influence quantities mentioned in clause 5 include temperature and proximity effects.
Others, like limited resolution of the measuring instrument, may be added if necessary. NOTE oec The resolution of a measuring instrument, e. During the actual voltage test, it is usually necessary to consider additional influencing quantities, apart from the calibration uncertainty 6006-02 the scale factor stated in the calibration certificate, in order to obtain the uncertainty of measurement of the test voltage value.
Some guidance on determining uncertainty contributions, that need to be considered, and on their combination is given in Clause 5 and Annexes A and B. The assigned scale factor is a single value for the assigned measurement range.
Full text of “IS/IEC High – Voltage Test Techniques, Part 2: Measuring Systems”
If necessary, several assigned measurement ranges with different scale factors may be defined. For an impulse measuring system, the performance tests also show that its dynamic performance is adequate for the specified measurements and that the level of any interference is less 60006-2 the specified limits.
Due to the large size of the equipment and the real environmental conditions, the calibration should preferably be performed on site by comparison with a reference measuring system. Smaller size measuring systems or their components may be transported to another laboratory oec calibration in an arrangement that simulates the operating conditions, provided that the interference test, when specified, is performed in 6006-02 test facility of the user.
If a converting device is sensitive to lec effects, 600660-2 range of clearances where the assigned scale factor is valid shall be determined and entered in the record of performance. One or more 6006-2 of clearances and respective scale factors may be assigned. The scale factor of a measuring system shall be determined in the assigned measurement range, preferably by comparison with a reference measuring system. One of the methods given in 5.
Conditions significant for the result of the calibration of the approved measuring ied shall be included in the record of performance. The input voltage used for calibration should be of the same type, frequency or waveform as 60060–2 to be measured. If this condition is not fulfilled, the related uncertainty contributions shall be estimated.
For the comparison, a reference measuring system, traceable to a National IVIetrology Institute, shall be connected in parallel with the measuring system to be calibrated.
Simultaneous readings shall be taken on both systems. The mean value is given by: NOTE 2 For measurement of direct and alternating voltages, independent readings should be obtained either by applying the test voltage and taking n readings or by applying the test voltage n times and taking a reading each time.
For impulses, n impulses 6006-2 applied. A measuring system with several assigned measuring ranges for example a voltage divider with several low-voltage arms or different transmission systems shall be calibrated for each range or eic system.
IVIeasuring systems with secondary attenuators may be calibrated on one setting only, provided that the load on the output of the converting device can be shown to be constant for all settings by other tests. For such cases the full range of secondary attenuators shall be calibrated separately. The scale factor shall be determined over the assigned measurement range by one of the following methods described in 5. The scale factor determination shall be made by direct comparison with a reference measuring system at the minimum and maximum levels of the assigned measurement range and on at least three approximately equally spaced intermediate levels Figure 2.
The comparison shall be complemented by a linearity test in accordance with 5. The uncertainty contribution related to linearity shall be considered in the calculation of measurement uncertainty when using the measuring system, see 5.