Sennheiser SZI 1029-10 manual Infra-Redtechnology, see AVAILABLE MODELS, Wideband, Narrow-Band

INFRA-RED TECHNOLOGY	The SZI 1029 is a high power infra-red radiator. In a cordless infra-red
	sound transmission system it transforms the electrical signal delivered
	by an infra-red modulator or by an audio source into invisible infra-red
	light and radiates this IR light into a room. In contrast to radio
	transmission infra-red transmission is limited to the room, thus other
	systems can be operated in neighbouring rooms without interference.
	￿ The high-power radiator SZI 1029 is switched on by the IR carrier
	signal that is produced by the modulator. Commercially available
	50 Ω coaxial cables with BNC connectors are used for feeding
	sig nals from the modulator to the SZI 1029 radiator.
	The infra-red radiator diodes in the high power radiator respond to the
	received signals and radiate modulated infra-red light. Depending on
	the model the radiator delivers a radiating power of 5 or 10 W
	(see AVAILABLE MODELS).
WIDEBAND	Infra-red wideband transmission systems are chiefly used for transmitting
	audio signals in hi-fi quality.
	The two available wideband channels (2.3 MHz and 2.8 MHz) are
	internationally standardized and are either used for two mono channels
	or for stereo transmission.
NARROW-BAND	Infra-red narrow-band transmission systems allow the transmission of
	up to 32 mono channels with a slightly reduced audio frequency response.
	They are ideal for multi-channel interpretation systems and multilingual
	information systems.
AREAS OF APPLICATION	￿ Conference and simultaneous interpretation systems
	￿ High quality cordless sound transmission in recording studios
	or for hi-fi systems

PROPAGATION OF	The propagation of the infra-red signal radiated by the SZI 1029 can be
INFRA-RED LIGHt	compared to the propagation of normal daylight or artifical (lamp) light.
	Thus it is subject to similar conditions when it falls onto different
	materials:
		IR light	IR light	IR light
		IR-Licht	IR-Licht	IR-Licht

ReflectionReflexion ReflectionReflexion ReflexionReflection

IMPACT OF CURTAINS,	•	Dark and heavy materials, curtains, carpets, panellings, and wall
CARPETS, AND PAINTS		coverings tend to absorb the light, a good reception can only be
		achieved in direct line of sight of the infra-red radiator.
	• Roughcast and strongly structured wallpapers (such as woodchip,
		embossed or fabric papers) reflect the light unevenly but allow a
		more uniform propagation of the infra-red signal.
	•	Smooth and bright walls, smooth tiled floors and windows are
		highly reflective and are thus favourable for the propagation of in
		fra-red light.

• Different wall paints may reflect infra-red light differently although they have the same colour. This is due to the type and thecomposit- ion of the paint pigmentation.

The power which is necessary to irradiate a room varies accordingly.

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