AS NZS 61786.1:2021 pdf free.Measurement of DC magnetic, AC magnetic and AC electric fields from 1 Hz to 100 kHz with regard to exposure of human beings Part 1: Requirements for measuring instruments (IEC 61786-1:2013 (ED.1.0) MOD).
5.1 General
When measuring field in the context of assessment of human exposure, the following items are considered below:
— measurement of the resultant field strength;
— measurement of the unperturbed electric field.
NOTE 1 Other items may be required depending on the goal of the measurement.
The various types of instrumentation available for characterizing quasi-static magnetic fields are described in Clause D.1.
The various types of instrumentation available for characterizing static magnetic fields are described in Clause D.3
Several types of magnetic field meters are in common use, e.g. field meters with coil probes, meters with Hall-effect probes, and meters that combine two coils with a ferromagnetic core as in a fluxgate magnetometer.
NOTE 2 Hall effect probes respond to static as well as time-varying magnetic flux densities. Due to limited sensitivity and saturation problems sometimes encountered when attempting to measure small power frequency flux densities in the presence of the substantial static geomagnetic flux of the earth, Hall-effect probes have seldom been used to measure magnetic fields of a.c. power lines.
The various types of instrumentation available for characterizing quasi-static electric fields are described in Clause E.1. The following two types of electric field meters are considered in this standard:
a) the free-body meter;
b) the ground reference meter.
Sufficient information shall be provided with the instrumentation, including instrument specifications and a clearly written instruction manual, to enable users to determine compliance with this standard, to aid them in the proper operation of the field meter, and to assess the usefulness of the device for the user’s application. The instrument specifications that shall be provided and/or satisfied are given below.
5.2 Measurement uncertainty
The measurement uncertainty of the measuring instrument shall be specified by the manufacturer of the instrument. The measurement uncertainty shall be determined following the ISO/IEC Guide 98-3. The uncertainty shall be specified as an extended measurement uncertainty using a coverage factor of 2. The uncertainty is valid after available correction factors are applied. The uncertainty shall contain all components which are relevant when the instrument is used in a nearly uniform field. Such components may be calibration uncertainty, frequency response, deviations of the gain in different measurement range settings, isotropy of the probe, internal noise sources, non-linearity, stability, temperature response and humidity response. The uncertainty of the instrument does not include effects due to the handling of the instrument like positioning the probe in a non-uniform field or the influence of the measuring person on the field to be measured. Such components must be taken into account as additional uncertainties in the measurement report.
NOTE 1 At power frequency, the uncertainty of measuring instrument is usually 10 % or better.
NOTE 2 Examples of guidelines on the treatment of calibration uncertainties are given in Annex B.AS NZS 61786.1 pdf download.