ETSI ETS 300 441, Инструкция по эксплуатации

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ETS 300 441: February 1996
4 General requirements
4.1 Construction
4.1.1 Equipment elements
The equipment shall comprise the following elements:
- a receiver;
- a loudspeaker;
- a filtering unit and/or a muting device to silence the loudspeaker in the absence of any of the signals
stated in clause 8;
- optionally, a device may be provided for disconnecting the filter, muting device or both during the
periods of radiotelephone silence.
4.1.2 Design
In all respects the mechanical and electrical design, construction and finish of the equipment shall
conform with good engineering practice, and the equipment shall be suitable for use on board ships at
sea.
4.1.3 Inspection and maintenance
All parts of the equipment which are subject to inspection and maintenance adjustments shall be easily
accessible. Components shall be easily identifiable, either by markings within the equipment or with the
aid of the technical description.
The equipment shall be so designed that the main units can be replaced readily, without elaborate
recalibration or readjustment.
4.1.4 Illumination
Means shall be provided for reducing, to extinction, the output of any light source on the equipment.
4.1.5 Interfaces
Connection of, or failure within, any external circuits shall not degrade the performance of the equipment.
4.2 Controls and indicators
4.2.1 General
All controls, instruments, monitoring devices and input/output points shall be clearly labelled.
All controls shall be of sufficient size to enable the usual control functions to be easily performed.
4.2.2 Controls
Only the following controls shall be provided on the exterior of the equipment:
- on/off switch;
- volume control for adjusting the audio frequency power as described in subclause 7.1;
- control for reducing the brightness of light sources, as described in subclause 4.1.4;
- muting device control or controls where clause 8 applies;
- filter control where subclause 8.4 applies;