BS 8243-2021 pdf free download.Design, installation and configuration of intruder and hold-up alarm systems designed to generate confirmed alarm conditions — Code of practice
4.2 Alarm confirmation technology
COMMENTARY ON 4.2
Alarm confirmation technology aims to provide high confidence that an alarm signal has been caused by a genuine or attempted intrusion alarm or HUA.
Alarm signals can be confirmed in a number of ways but, typically, they fall into two categories:
a) confirmed by the CIE, e.g. by processing sequential alarms; or
b) confirmed by an ARC or ARC operator, e.g. by listening, talking and/or viewing.
Where confirmation is determined by an operator, there might be an element of subjectivity surrounding what is heard or seen. In these circumstances, the operator is advised not to call the emergency services unless there is positive evidence of crime in progress.
4.2.1 Intruder alarm systems (IAS)
The IAS should incorporate one or a combination of the following forms of confirmation technology:
a) sequential confirmation technology (see 5.2);
b) audio confirmation technology (see 5.3); or
c) visual confirmation technology (see 5.4).
4.2.2 Hold-up alarm systems (HAS)
Where confirmation of a HUA is required, one or a combination of the following alarm confirmation technologies should be incorporated:
a) sequential confirmation (see 5.2);
b) audio confirmation (see 5.3);
c) visual confirmation (see 5.4); or
d) telephone confirmation (call back) (see 5.5).
An explanation of the selected combinations should be provided to the user/client.
The installer should obtain written confirmation of the client/user’s acceptance of the chosen option,and detail how the confirmation works.
NOTE Confirmation of a HUA is not mandatory unless restoration of police response is required following false activations (see NPCC and ACPOS/PS security systems policies [1] [2]).
4.3 Transmission fault signals handled by the ARC
COMMENTARY ON 4.3
The ARC treats the following two circumstances, involving transmission fault signals, as confirmed alarms as there is likely to be high confidence that it is a genuine alarm:
a) if an ARC receives a transmission fault signal followed by an alarm/tamper signal, or an alarm/tamper signal followed by a transmission fault from the same supervised premises during a single
set period of up to a maximum of 96 h;
b) for systems with more than one transmission path, a failure of all paths that occur within the same single set period of up to a maximum of 96 h.
The combination of a transmission fault signal and a HUA condition is interpreted as a confirmed HUA.
Connection to multiple transmission paths is optional and by agreement with the client.
See example procedures in Annex B and Annex C.
Where single path signalling is proposed or used, a warning should be included in the system design proposal and as-fitted document in accordance with Annex D, D.1.
The alarm company should inform the client in writing, at the time of arranging the alarm monitoring agreement between the alarm company and the client, of the actions to be taken by the ARC upon receipt of a transmission fault signal or transmission fault signals.
4.4 Informing the ARC of changes in police response
As soon as the alarm company becomes aware of any I&HAS having been taken off or put back on police response, the alarm company should inform the ARC.
5 Design, installation and configuration of I&HAS incorporating alarm
confirmation technology
5.1 General
5.1.1 Design process
The design and configuration of I&HAS incorporating alarm confirmation technology should take into account the needs and expectations of the client and the required response to alarms. The design process should incorporate the entire supervised premises.
NOTE 1 It is a matter of system design, in meeting the needs and expectations of the client, as to whether alarm confirmation technology is applied to every room or area within the supervised premises, or only to certain rooms or areas.
Detectors installed outside the supervised premises should not contribute to the generation of audibly, visually or sequentially confirmed alarms.
The need for the use of extended format reporting should be determined.
NOTE 2 Extended format reporting can be helpful in providing additional information about intrusion, including:
a) the locations of detectors that have activated;
b) multiple activations of detectors; and/or
c) identi fication of perimeter detectors that have activated.
The system design proposal and as-fitted document should clearly state the scope, extent and coverage of the confirmation facility, including those areas within the supervised premises that are within the expected range and proximity of ALD, AMD or the field of view of imaging devices (see Annex D).
The system design proposal and the as-fitted document should identify the specified parts of the supervised premises that have confirmation facility.
5.1.2 Control indicating equipment (CIE) and notification equipment
The CIE and notification equipment should be located and supervised such as to minimize the risk of vandalism or sabotage.
NOTE It is preferable for the CIE and signalling and network equipment to be located in an area designed to generate a confirmed activation.
5.1.3 Design recommendations for HAS using confirmed technology
The HAS should be installed such as to minimize the risk of accidental operation and false activation.
a) HDs on CIE or ACE should not be enabled unless there is a low risk of accidental operation.
b) Single action “single push devices” should not be used.BS 8243 pdf download.