Jarvis_table1

NOTE: These tests are designed to ensure a minimum acceptable immunity to amplitude-modulated radio-frequency disturbances for devices having acoustic interfaces. The demodulated disturbance levels are higher than those that will be found acceptable in practice. The levels in the tests have been chosen for their practical test convenience, having regard for the maximum allowed background acoustic noise level of 40 dB(spl) and the test levels to be applied for functional testing. The amplitude-demodulated disturbances will arise, almost invariably, from semiconductor junctions behaving as inadvertent square-law detectors. This means that for every 1-dB change in the level of the applied radio-frequency signal, the demodulated level will change by 2 dB. Therefore, if a radiated immunity test subjecting the EUT to a test field carrier level of 3 V/m produces a resultant demodulated acoustic 1-KHz disturbance output of 55 dB(spl) (a distinctly annoying acoustic level for most listeners with normal hearing, but conveniently above the allowed background noise level of 40 dB(spl)), the test ensures that an amplitude-modulated disturbance field of 1 V/m (approximately 10 dB lower in field strength) applied to the same equipment in a real-world situation can produce a demodulated acoustic-disturbance level of approximately 35 dB(spl), which most people in a practical listening environment do not perceive as annoying

Frequency Band (MHz)	Type of Immunity Test	Noise Signal (dBm)	Acoustic Sound Pressure Level (dB (spl))
0.15 to 30	Conducted	–50	55
30 to 40.66	Conducted	–30	75
40.66 to 40.7	Conducted	–50	55
40.7 to 80	Conducted	–30	75
80 to 1000 (except at 900*)	Radiated	–30	75
900*	Radiated	–50	55
*This requirement is not applicable for countries where no digital mobile service operating at 900 MHz exists. NOTE: These tests are designed to ensure a minimum acceptable immunity to amplitude-modulated radio-frequency disturbances for devices having acoustic interfaces. The demodulated disturbance levels are higher than those that will be found acceptable in practice. The levels in the tests have been chosen for their practical test convenience, having regard for the maximum allowed background acoustic noise level of 40 dB(spl) and the test levels to be applied for functional testing. The amplitude-demodulated disturbances will arise, almost invariably, from semiconductor junctions behaving as inadvertent square-law detectors. This means that for every 1-dB change in the level of the applied radio-frequency signal, the demodulated level will change by 2 dB. Therefore, if a radiated immunity test subjecting the EUT to a test field carrier level of 3 V/m produces a resultant demodulated acoustic 1-KHz disturbance output of 55 dB(spl) (a distinctly annoying acoustic level for most listeners with normal hearing, but conveniently above the allowed background noise level of 40 dB(spl)), the test ensures that an amplitude-modulated disturbance field of 1 V/m (approximately 10 dB lower in field strength) applied to the same equipment in a real-world situation can produce a demodulated acoustic-disturbance level of approximately 35 dB(spl), which most people in a practical listening environment do not perceive as annoying
Table I. Maximum acoustic demodulated levels at the telecommunications port and at the acoustic receiving device (measurement method 1). Reproduced from CISPR 24, Table A.1 with permission of the International Electrotechnical Commission.