IEEE C37.90.2-1987 pdf free.IEEE Trial-Use Standard Withstand Capability of Relay Systemsto Radiated Electromagnetic Interference from Transceivers.
IEEE C37.90.25. procedure assumes the use ofbiconical and conical logarithmic antennas. Othermethods of establishing the fields are acceptableproviding the proper fields can be generated.Set up the test sample and the transmittingantenna per the distance restrictions of Fig 1.Forthe biconical transmitting antenna,adjust itso that the electromagnetic field is polarizedvertically.
Establish the field strength by placing thefield strength receiving antenna or antennas inplace of the test samples.Sweep a continuouswave signal to the applicable antenna over a fre-quency range of 25-1000 MHz. Monitor the fieldstrength via a remote field strength indicator outside the test chamber. During this determination,the transmitter power shall be adjusted so thatthe monitored field strength stays between 10and 20 V/m.
Replace the receiving antenna with the testsample and repeat the frequency sweep using thesame source power setting(s) used in step (2).Document the response of the test sample.Auto-matic sweep rate should be at 0.005 octaves/second or less. If manual sweep is utilized, thesweep rate should approximate 0.005 octave/second or less. For frequencies below 50 MHz,amplitude modulate at 90% with a 1000 Hz sinewave. (See 5.5.3 for digital equipment.)
Step ( 3) shall be repeated to expose thetest sample in other planes as follows:
Floor mounted equipment— four sides ofthe equipment shall be exposed to the test source. Other than floor mounted equipment—six sides of the equipment shall be exposed to thetest source.
Digital Equipment Modulation Test. Alldigital equipment using clocked logic circuits shallalso be subjected to electromagnetic radiationthat is amplitude (pulse or square wave) modu-lated at a frequency close to 10 kHz, but not insynchronism with the digital clock frequency. The1000 Hz sine wave modulation listed in step (3) of5.5.2 may be omitted when the 10 kHz modulationtest is performed.Keying Test.Some equipment is susceptible to repeated operation of a transmitter. Thistest shall be performed to evaluate the testspecimen in this mode.To simulate keying of atransceiver, the signal source shall be 100% pulseor square wave modulated.The modulating signalshall have an on and off duration of at least 1 seach.The pulse or square wave shall have a riseand fall time of no greater than 50 us. There shallbe at least three keying cycles per frequencyoctave. Exposure need be to the front of the testspecimen only.IEEE C37.90.2 pdf download.