IEEE ANSI C63.6-1996 pdf download American National Standard Guide for the Computation of Errors in Open-Area Test Site Measurements
1.Scope
This guide shows the basis for the acceptability criterion of +4 dB for the site attenuation measurementsrequired in ANSI C63.4-1992.
2. References
This guide shall be used in conjunction with the following publications. When the following standards aresuperseded by an approved revision, the revision shall apply.
ANSI C63.2-1996,American National Standard for Electromagnetic Noise and Field Strength Instrumenta-tion.10 Hz to 40 GHz-Specifications.
ANSI C63.4-1992,American National Standard for Methods of Measurement of Radio-Noise Emissionsfrom Low-Voltage Electrical and Electronics Equipment in the Range of 9 kHz to 40 GHz.
ANSI C63.14-1992,American National Standard Dictionary for Technologies of Electromagnetic Compati-bility (EMC), Electromagnetic Pulse (EMP), and Electrostatic Discharge (ESD).
IEEE Std 100-1996, The IEEE Standard Dictionary of Electrical and Electronics Terms.
3. Definitions
The definitions found in the four references in Clause 2 are by reference incorporated herein, and the definitions found in ANSI C63.14-1992 take precedence in the event of conflicts.
4. Error analysis The error analysis in Table 1 applies to the normalized site attenuation measurement method given in 5.4.6 of ANSI C63.4-1992. The total estimated errors are the basis for the ±4 dB site acceptability criterion in 5.4.6.1 of ANSI C63.4-1992 (i.e., approximately 3 dB measurement uncertainty and an allowable 1 dB for site imperfections, added linearly in decibels).
The error budget in Table 1 does not include uncertainties in the amplitude stability of the signal generator or tracking generator, and any ampliÞers that may be used, nor does it include the potential errors in the track- ing generator leveling or measurement technique. The output level of most signal and tracking generators will drift with time and temperature, and the gain of many ampliÞers will drift as temperature changes. It is imperative that these sources of error be held to an insigniÞcant amount or corrected in making the measure- ments; otherwise, the measurements may indicate that the site fails to meet the acceptability criterion.
From the operating instructions for a typical automatic spectrum analyzer, for example, if everything is done to remove or compensate every potential error as much as possible, the remaining amplitude errors are as follows:
a) ±0.2 dB calibrator uncertainty
b) ±1.0 dB frequency response ßatness
c) ±1.0 dB input attenuator switching
d) ±0.4 dB radio frequency (RF) and intermediate frequency (IF) gain uncertainty
This gives a total potential error of ±2.6 dB. This does not include ±0.05 dB/ ° C temperature drift. In prac- tice, when performing substitution type measurements, the errors associated with the frequency response ßatness and input attenuator switching are usually 1 dB less, so that the total error band for the spectrum analyzer as a two-terminal voltmeter is ±1.6 dB or less, which is used in Table 1.
IEEE ANSI C63.6-1996 pdf download
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