The requirements of this chapter shall apply where required by the enforcing authority; governing laws, codes, or standards; or other parts of this Code.
The performance, location, and mounting of notification appliances used to initiate or direct evacuation or relocation of the occupants, or for providing information to occupants or staff, shall comply with this chapter.
The performance, location, and mounting of annunciators, displays, and printers used to display or record information for use by occupants, staff, responding emergency personnel, or supervising station personnel shall comply with this chapter.
The requirements of this chapter shall apply to the areas, spaces, or system functions where required by the enforcing authority; governing laws, codes, or standards; or other parts of this Code requiring compliance with this chapter.
The requirements of Chapters 10, 14, 23, and 24 shall apply to the interconnection of notification appliances, the control configurations, the power supplies, and the use of the information provided by notification appliances.
Notification appliances shall be permitted to be used within buildings or outdoors and to target the general building, area, or space, or only specific parts of a building, area, or space designated in specific zones and sub-zones.
Notification appliances shall provide stimuli for initiating emergency action and provide information to users, emergency response personnel, and occupants.
All notification appliances installed in conformity with Chapter 18 shall be listed for the purpose for which they are used.
Notification appliances shall include on their nameplates reference to electrical requirements and rated audible or visible performance, or both, as defined by the listing authority.
Visible appliances shall include on their nameplates reference to their parameters or reference to installation documents (supplied with the appliance) that include the parameters in accordance with 18.5.3.1 or Section 18.6.
Appliances intended for use in special environments, such as outdoors versus indoors, high or low temperatures, high humidity, dusty conditions, and hazardous locations, or where subject to tampering, shall be listed for the intended application.
Notification appliances used for signaling other than fire shall not have the word FIRE, or any fire symbol, in any form (i.e., stamped, imprinted, etc.) on the appliance visible to the public. Notification appliances with multiple visible elements shall be permitted to have fire markings only on those visible elements used for fire signaling.
Appliances subject to mechanical damage shall be suitably protected.
If guards, covers, or lenses are employed, they shall be listed for use with the appliance.
The effect of guards, covers, or lenses on the appliance's field performance shall be in accordance with the listing requirements.
Appliances shall be mounted in accordance with the manufacturer's published instructions.
Terminals, leads, or addressable communication, that provide for monitoring the integrity of the notification appliance connections shall be provided.
An average ambient sound level greater than 105 dBA shall require the use of a visible notification appliance(s) in accordance with Section 18.5 where the application is public mode or Section 18.6 where the application is private mode.
The total sound pressure level produced by combining the ambient sound pressure level with all audible notification appliances operating shall not exceed 110 dBA at the minimum hearing distance.
Sound from normal or permanent sources, having a duration greater than 60 seconds, shall be included when measuring maximum ambient sound level. Sound from temporary or abnormal sources shall not be required to be included when measuring maximum ambient sound level.
Audible alert and evacuation signal tones shall meet the requirements of 18.4.3 (Public Mode Audible Requirements), 18.4.4 (Private Mode Audible Requirements), 18.4.5 (Sleeping Area Requirements), or 18.4.6 (Narrow Band Tone Signaling for Exceeding Masked Thresholds), as applicable. This requirement shall include audible tones that preceded or follow voice messages.
The designer of the audible notification system shall identify the rooms and spaces that will have audible notification and those where audible notification will not be provided.
Unless otherwise required by other sections of this Code, the coverage area for audible occupant notification shall be as required by other governing laws, codes, or standards. Where the other governing laws, codes, or standards require audible occupant notification for all or part of an area or space, coverage shall only be required in occupiable areas as defined in 3.3.177.
The sound pressure levels that must be produced by the audible appliances in the coverage areas to meet the requirements of this Code shall be documented by the system designer during the planning and design of the notification system. The greater of the expected average ambient sound pressure level or expected maximum sound pressure level having a duration of at least 60 seconds shall also be documented for the coverage area by the system designer to ensure compliance with 18.4.3, 18.4.4, 18.4.5, or 18.4.6 for the coverage area.
The design sound pressure levels to be produced by the notification appliances for the various coverage areas shall be documented for use during acceptance testing of the system.
Where required by the authority having jurisdiction, documentation of the design sound pressure levels for the various coverage areas shall be submitted for review and approval.
Voice messages shall not be required to meet the audibility requirements of 18.4.3 (Public Mode Audible Requirements), 18.4.4 (Private Mode Audible Requirements), 18.4.5 (Sleeping Area Requirements), or 18.4.6 (Narrow Band Tone Signaling for Exceeding Masked Thresholds), but shall meet the intelligibility requirements of 18.4.10 where voice intelligibility is required.
Audible notification appliances used for exit marking shall not be required to meet the audibility requirements of 18.4.3 (Public Mode Audible Requirements), 18.4.4 (Private Mode Audible Requirements), 18.4.5 (Sleeping Area Requirements), or 18.4.6 (Narrow Band Tone Signaling for Exceeding Masked Thresholds), except as required by 18.4.7 (Exit Marking Audible Appliance Requirements).
To meet the requirements of Section 10.10, the alarm audible signal pattern used to notify building occupants of the need to evacuate (leave the building) or relocate (from one area to another) shall be the standard alarm evacuation signal consisting of a three-pulse temporal pattern. The pattern shall be in accordance with Figure 18.4.2.1 and shall consist of the following in this order: 
- "On" phase lasting 0.5 second ±10 percent
- "Off" phase lasting 0.5 second ±10 percent for three successive "on" periods
- "Off" phase lasting 1.5 seconds ±10 percent
Exception: Where approved by the authority having jurisdiction, continued use of the existing consistent evacuation signaling scheme shall be permitted.
FIGURE 18.4.2.1 Temporal Pattern Parameters.
A single-stroke bell or chime sounded at "on" intervals lasting 1 second ±10 percent, with a 2-second ±10 percent "off" interval after each third "on" stroke, shall be permitted.
The signal shall be repeated for a period appropriate for the purposes of evacuation of the building, but for not less than 180 seconds.
The minimum repetition time shall be permitted to be manually interrupted.
The minimum repetition time shall be permitted to be automatically interrupted for the transmission of mass notification messages in accordance with Chapter 24.
The standard evacuation signal shall be synchronized within a notification zone.
To ensure that audible public mode signals are clearly heard, unless otherwise permitted by 18.4.3.2 through 18.4.3.5, they shall have a sound level at least 15 dB above the average ambient sound level or 5 dB above the maximum sound level having a duration of at least 60 seconds, whichever is greater, measured 5 ft (1.5 m) above the floor in the area required to be served by the system using the A-weighted scale (dBA).
Where approved by the authority having jurisdiction or other governing codes or standards, the requirements for audible signaling shall be permitted to be reduced or eliminated when visible signaling is provided in accordance with Section 18.5.
Audible alarm notification appliances installed in elevator cars shall be permitted to use the audibility criteria for private mode appliances detailed in 18.4.4.1.
If approved by the authority having jurisdiction, audible alarm notification appliances installed in restrooms shall be permitted to use the audibility criteria for private mode appliances detailed in 18.4.4.1.
A signaling system arranged to stop or reduce ambient noise shall comply with 18.4.3.5.1 through 18.4.3.5.3.
A signaling system arranged to stop or reduce ambient noise shall produce a sound level at least 15 dB above the reduced average ambient sound level or 5 dB above the maximum sound level having a duration of at least 60 seconds after reduction of the ambient noise level, whichever is greater, measured 5 ft (1.5 m) above the floor in the area required to be served by the system using the A-weighted scale (dBA).
Visible notification appliances shall be installed in the affected areas in accordance with Sections 18.5 or 18.6.
To ensure that audible private mode signals are clearly heard, they shall have a sound level at least 10 dB above the average ambient sound level or 5 dB above the maximum sound level having a duration of at least 60 seconds, whichever is greater, measured 5 ft (1.5 m) above the floor in the area required to be served by the system using the A-weighted scale (dBA).
Where approved by the authority having jurisdiction or other governing codes or standards, the requirements for audible signaling shall be permitted to be reduced or eliminated when visible signaling is provided in accordance with Section 18.5.
A system arranged to stop or reduce ambient noise shall comply with 18.4.4.3.1 through 18.4.4.3.3.
A system arranged to stop or reduce ambient noise shall be permitted to produce a sound level at least 10 dB above the reduced average ambient sound level or 5 dB above the maximum sound level having a duration of at least 60 seconds after reduction of the ambient noise level, whichever is greater, measured 5 ft (1.5 m) above the floor, using the A-weighted scale (dBA).
Visible notification appliances shall be installed in the affected areas in accordance with Sections 18.5 or 18.6.
Where audible appliances are installed to provide signals for sleeping areas, they shall have a sound level of at least 15 dB above the average ambient sound level or 5 dB above the maximum sound level having a duration of at least 60 seconds or a sound level of at least 75 dBA, whichever is greater, measured at the pillow level in the area required to be served by the system using the A-weighted scale (dBA).
If any barrier, such as a door, curtain, or retractable partition, is located between the notification appliance and the pillow, the sound pressure level shall be measured with the barrier placed between the appliance and the pillow.
Audible appliances provided for the sleeping areas to awaken occupants shall produce a low frequency alarm signal that complies with the following:
- The alarm signal shall be a square wave or provide equivalent awakening ability.
- The waveform shall have a fundamental frequency of 520 Hz ± 10 percent.
- *The notification equipment shall be listed for producing the low frequency waveform.
The effective masked threshold shall be calculated in accordance with ISO 7731, Danger signals for work places — Auditory danger signals.
Noise data for calculating the effective masked threshold shall be the peak value of noise lasting 60 seconds or more for each octave or one-third octave band.
Analysis and design documentation shall be submitted to the authority having jurisdiction and shall contain the following information:
- Frequency data for the ambient noise, including the date, time, and location where measurements were taken for existing environments, or projected data for environments not yet constructed
- Frequency data of the audible notification appliance
- Calculations of the effective masked threshold for each set of noise data
- A statement of the sound pressure level that would be required by 18.4.3 or 18.4.4 if masked threshold signaling had not been done
For masked threshold signaling, the audible signal tone shall meet the requirements of either 18.4.6.5.1 or 18.4.6.5.2 but not for the reproduction of prerecorded, synthesized, or live messages.
The sound pressure level of the audible tone signal shall exceed the masked threshold in one or more octave bands by at least 10 dB in the octave band under consideration.
The sound pressure level of the audible tone signal shall exceed the masked threshold in one or more one-third octave bands by at least 13 dB in the one-third octave band under consideration.
Exit marking audible notification appliances shall meet or exceed the frequency and sound level settings and guidelines specified in the manufacturer's documented instructions.
In addition to 18.4.7.1, as a minimum, to ensure that exit marking audible notification appliance signals are clearly heard and produce the desired directional effects for 50 ft (15.24 m) within an unobstructed egress path, they shall meet the audibility requirements of 18.4.6 in at least one one-third octave band or one octave band within the effective frequency ranges of the interaural time difference (ITD), interaural level or intensity difference (ILD or IID), and anatomical transfer function or head-related transfer function (ATF or HRTF) localization cues. The signal shall penetrate both the ambient noise and the fire alarm signal.
Where required by the enforcing authority; governing laws, codes, or standards; or other parts of this Code, exit marking audible notification appliances shall be installed in accordance with the manufacturer's instructions.
Where required by the enforcing authority; governing laws, codes, or standards; or other parts of this Code, exit marking audible notification shall be located at the entrance to all building exits and areas of refuge as defined by the applicable building or fire code.
Where exit marking audible notification appliances are utilized to mark areas of refuge, they shall provide an audible signal distinct from that used for other exits that do not have areas of refuge.
If ceiling heights allow, and unless otherwise permitted by 18.4.8.2 through 18.4.8.5, wall-mounted appliances shall have their tops above the finished floors at heights of not less than 90 in. (2.29 m) and below the finished ceilings at distances of not less than 6 in. (150 mm).
If combination audible/visible appliances are installed, the location of the installed appliance shall be determined by the requirements of 18.5.5.
Appliances that are an integral part of a smoke detector, smoke alarm, or other initiating device shall be located in accordance with the requirements for that device.
Audible notification appliances for wide-area signaling shall be installed in accordance with the requirements of the authority having jurisdiction, approved design documents, and the manufacturer's installation instruction to achieve the required performance.
Within the acoustically distinguishable spaces (ADS) where voice intelligibility is required, voice communications systems shall reproduce prerecorded, synthesized, or live (e.g., microphone, telephone handset, and radio) messages with voice intelligibility.
ADSs shall be determined by the system designer during the planning and design of all emergency communications systems.
Unless specifically required by other governing laws, codes, or standards, or by other parts of this Code, intelligibility shall not be required in all ADSs.
Where required by the enforcing authority; governing laws, codes, or standards; or other parts of this Code, ADS assignments shall be submitted for review and approval.
Intelligibility shall not be required to be determined through quantitative measurements.
Quantitative measurements as described in D.2.4 shall be permitted but are not required.
Public mode visible signaling shall meet the requirements of Section 18.5 using visible notification appliances.
The coverage area for visible occupant notification shall be as required by other governing laws, codes, or standards. Where the other governing laws, codes, or standards require visible occupant notification for all or part of an area or space, coverage shall only be required in occupiable areas as defined in 3.3.177.
The designer of the visible notification system shall document the rooms and spaces that will have visible notification and those where visible notification will not be provided.
Unless otherwise specified or required by other sections of this Code, the required coverage area for visible occupant notification shall be as required by other governing laws, codes, or standards.
Where required by the authority having jurisdiction, documentation of the effective intensity (cd) of the visible appliances for the area of coverage shall be submitted for review and approval.
The flash rate shall not exceed two flashes per second (2 Hz) nor be less than one flash every second (1 Hz) throughout the listed voltage range of the appliance.
The pulse duration shall be defined as the time interval between initial and final points of 10 percent of maximum signal.
Lights used for fire alarm signaling only or to signal the intent for complete evacuation shall be clear or nominal white and shall not exceed 1000 cd (effective intensity).
Lights used to signal occupants to seek information or instructions shall be clear, nominal white, or other color as required by the emergency plan and the authority having jurisdiction for the area or building.
The strobe synchronization requirements of this chapter shall not apply where the visible notification appliances located inside the building are viewed from outside of the building.
The light output shall comply with the polar dispersion requirements of ANSI/UL 1971, Standard for Signaling Devices for the Hearing Impaired, or equivalent.
Wall-mounted appliances shall be mounted such that the entire lens is not less than 80 in. (2.03 m) and not greater than 96 in. (2.44 m) above the finished floor or at the mounting height specified using the performance-based alternative of 18.5.5.6.
Where low ceiling heights do not permit wall mounting at a minimum of 80 in. (2.03 m), wall mounted visible appliances shall be mounted within 6 in. (150 mm) of the ceiling. The room size covered by a strobe of a given value shall be reduced by twice the difference between the minimum mounting height of 80 in. (2.03 m) and the actual lower mounting height.
Spacing shall be in accordance with either Table 18.5.5.4.1(a) and Figure 18.5.5.4.1 or Table 18.5.5.4.1(b).
Table 18.5.5.4.1(a) Room Spacing for Wall-Mounted Visible Appliances
| Maximum Room Size | Minimum Required Light Output [Effective Intensity (cd)] | |||
|---|---|---|---|---|
| ft | m | One Light per Room | Four Lights per Room (One Light per Wall) | |
| 20 × 20 | 6.10 × 6.10 | 15 | NA | |
| 28 × 28 | 8.53 × 8.53 | 30 | NA | |
| 30 × 30 | 9.14 × 9.14 | 34 | NA | |
| 40 × 40 | 12.2 × 12.2 | 60 | 15 | |
| 45 × 45 | 13.7 × 13.7 | 75 | 19 | |
| 50 × 50 | 15.2 × 15.2 | 94 | 30 | |
| 54 × 54 | 16.5 × 16.5 | 110 | 30 | |
| 55 × 55 | 16.8 × 16.8 | 115 | 30 | |
| 60 × 60 | 18.3 × 18.3 | 135 | 30 | |
| 63 × 63 | 19.2 × 19.2 | 150 | 37 | |
| 68 × 68 | 20.7 × 20.7 | 177 | 43 | |
| 70 × 70 | 21.3 × 21.3 | 184 | 60 | |
| 80 × 80 | 24.4 × 24.4 | 240 | 60 | |
| 90 × 90 | 27.4 × 27.4 | 304 | 95 | |
| 100 × 100 | 30.5 × 30.5 | 375 | 95 | |
| 110 × 110 | 33.5 × 33.5 | 455 | 135 | |
| 120 × 120 | 36.6 × 36.6 | 540 | 135 | |
| 130 × 130 | 39.6 × 39.6 | 635 | 185 | |
| NA: Not allowable. | ||||
| Maximum Room Size | Maximum Lens Height* | Minimum Required Light Output (Effective Intensity); One Light (cd) | |||
|---|---|---|---|---|---|
| ft | m | ft | m | ||
| 20 × 20 | 6.1 × 6.1 | 10 | 3.0 | 15 | |
| 30 × 30 | 9.1 × 9.1 | 10 | 3.0 | 30 | |
| 40 × 40 | 12.2 × 12.2 | 10 | 3.0 | 60 | |
| 44 × 44 | 13.4 × 13.4 | 10 | 3.0 | 75 | |
| 20 × 20 | 6.1 × 6.1 | 20 | 6.1 | 30 | |
| 30 × 30 | 9.1 × 9.1 | 20 | 6.1 | 45 | |
| 44 × 44 | 13.4 × 13.4 | 20 | 6.1 | 75 | |
| 46 × 46 | 14.0 × 14.0 | 20 | 6.1 | 80 | |
| 20 × 20 | 6.1 × 6.1 | 30 | 9.1 | 55 | |
| 30 × 30 | 9.1 × 9.1 | 30 | 9.1 | 75 | |
| 50 × 50 | 15.2 × 15.2 | 30 | 9.1 | 95 | |
| 53 × 53 | 16.2 × 16.2 | 30 | 9.1 | 110 | |
| 55 × 55 | 16.8 × 16.8 | 30 | 9.1 | 115 | |
| 59 × 59 | 18.0 × 18.0 | 30 | 9.1 | 135 | |
| 63 × 63 | 19.2 × 19.2 | 30 | 9.1 | 150 | |
| 68 × 68 | 20.7 × 20.7 | 30 | 9.1 | 177 | |
| 70 × 70 | 21.3 × 21.3 | 30 | 9.1 | 185 | |
| *This does not preclude mounting lens at lower heights. | |||||
FIGURE 18.5.5.4.1 Room Spacing for Wall-Mounted Visible Appliances.
Visible notification appliances shall be installed in accordance with Table 18.5.5.4.1(a) or Table 18.5.5.4.1(b) using one of the following:
- A single visible notification appliance.
- *Two groups of visible notification appliances, where visual appliances of each group are synchronized, in the same room or adjacent space within the field of view. This shall include synchronization of strobes operated by separate systems.
- More than two visible notification appliances or groups of synchronized appliances in the same room or adjacent space within the field of view that flash in synchronization.
Room spacing in accordance with Table 18.5.5.4.1(a) and Figure 18.5.5.4.1 for wall-mounted appliances shall be based on locating the visible notification appliance at the halfway distance of the wall.
In square rooms with appliances not centered or in nonsquare rooms, the effective intensity (cd) from one visible wall-mounted notification appliance shall be determined by maximum room size dimensions obtained either by measuring the distance to the farthest wall or by doubling the distance to the farthest adjacent wall, whichever is greater, as required by Table 18.5.5.4.1(a) and Figure 18.5.5.4.1.
If a room configuration is not square, the square room size that allows the entire room to be encompassed or allows the room to be subdivided into multiple squares shall be used.
If ceiling heights exceed 30 ft (9.14 m), ceiling-mounted visible notification appliances shall be suspended at or below 30 ft (9.14 m) or at the mounting height determined using the performance-based alternative of 18.5.5.6, or wall-mounted visible notification appliances shall be installed in accordance with Table 18.5.5.4.1(a).
Table 18.5.5.4.1(b) shall be used if the ceiling-mounted visible notification appliance is at the center of the room. If the ceiling-mounted visible notification appliance is not located at the center of the room, the effective intensity (cd) shall be determined by doubling the distance from the appliance to the farthest wall to obtain the maximum room size.
The installation of visible notification appliances in corridors 20 ft (6.1 m) or less in width shall be in accordance with the requirements of either 18.5.5.4 or 18.5.5.5.
Paragraph 18.5.5.5 shall apply to corridors not exceeding 20 ft (6.1 m) in width.
In a corridor application, visible appliances shall be rated not less than 15 cd.
Visible notification appliances shall be located not more than 15 ft (4.57 m) from the end of the corridor with a separation not greater than 100 ft (30.5 m) between appliances.
If there is an interruption of the concentrated viewing path, such as a fire door, an elevation change, or any other obstruction, the area shall be treated as a separate corridor.
In corridors where more than two visible notification appliances are in any field of view, they shall flash in synchronization.
Wall-mounted visible notification appliances in corridors shall be permitted to be mounted on either the end wall or the side wall of the corridor in accordance with spacing requirements of 18.5.5.5.5.
Any design that provides a minimum of 0.0375 lumens/ft2 (0.4036 lumens/m2) of illumination at any point within the covered area at all angles specified by the polar dispersion planes for wall- or ceiling-mounted visual appliances in ANSI/UL 1971, Standard for Signaling Devices for the Hearing Impaired, or equivalent, as calculated for the maximum distance from the nearest visual notification appliance, shall be permitted in lieu of the requirements of 18.5.5, excluding 18.5.5.7.
Documentation provided to the authority having jurisdiction shall include the following:
- Inverse Square Law calculations using each of the vertical and horizontal polar distribution angles in ANSI/UL 1971, Standard for Signaling Devices for the Hearing Impaired, or equivalent.
- The calculations shall account for the effects of polar distribution using one of the following:
- The percentages from the applicable table(s) in ANSI/UL 1971, Standard for Signaling Devices for the Hearing Impaired, or equivalent
- The actual results of laboratory tests of the specific appliance to be used as recorded by the listing organization
Combination smoke detectors and visible notification appliances or combination smoke alarms and visible notification appliances shall be installed in accordance with the applicable requirements of Chapters 17, 18, and 29.
Table 18.5.5.7.2 shall apply to sleeping areas.
Table 18.5.5.7.2 Effective Intensity Requirements for Sleeping Area Visible Notification Appliances
| Distance from Ceiling to Top of Lens | Minimum Intensity (cd) | |
|---|---|---|
| in. | mm | |
| ≥24 | ≥610 | 110 |
| <24 | <610 | 177 |
For rooms with a linear dimension greater than 16 ft (4.87 m), the visible notification appliance shall be located within 16 ft (4.87 m) of the pillow.
Visible notification appliances for wide area signaling shall be installed in accordance with the requirements of the authority having jurisdiction, approved design documents, and the manufacturer's instructions to achieve the required performance.
Visible notification appliances used in the private mode shall be of a sufficient quantity and intensity and located so as to meet the intent of the user and the authority having jurisdiction.
A supplementary visible notification appliance shall be intended to augment an audible or visible signal.
A supplementary visible notification appliance shall comply with its marked rated performance.
Supplementary visible notification appliances shall be permitted to be located less than 80 in. (2.03 m) above the floor.
Speaker Appliances.
Speaker appliances shall comply with Section 18.4.
Textual and graphical visible appliances shall be permitted to be used to signal information about fire or other emergency conditions or to direct intended responses to those conditions.
This section does not apply to means of egress signs, room identification signs, and other signage that could be required by other governing laws, codes, or standards.
Textual visible appliance messages shall be permitted to be static, flashing, or scrolling.
Unless otherwise permitted or required by other governing laws, codes, or standards, or by other parts of this Code or by the authority having jurisdiction, all textual and graphical visible notification appliances in the private mode shall be located in rooms that are accessible only to those persons directly concerned with the implementation and direction of emergency response in the areas protected by the system.
Textual and graphical visible notification appliances used in the public mode shall be located to ensure visibility to the occupants of the protected area or to the intended recipients.
Desktop and surface-mounted textual and graphical appliances shall be permitted.
The information produced by textual and graphical visible appliances shall be clear and legible at the intended viewing distance.
This section applies to visual characters and graphic elements and does not address raised characters or braille that could be required by other governing laws, codes, or standards.
Characters and symbols shall contrast with their background using either positive contrast (light on a dark background) or negative contrast (dark on a light background).
Characters and symbols and their background shall have a nonglare finish.
Characters shall be permitted to be uppercase or lowercase, or a combination of both.
Characters shall be conventional in form and not italic, oblique, script, highly decorative, or of other unusual form and shall use sans serif fonts.
Characters shall be selected from fonts where the width of the uppercase letter "O" is 55 percent minimum and 110 percent maximum of the height of the uppercase letter "I".
Character and symbol height for appliances other than desktop monitors or displays shall meet all of the following criteria:
- Minimum character height shall comply with Table 18.9.4.7.
- Viewing distance shall be measured as the horizontal distance between the character and an obstruction preventing further approach towards the appliance.
- Character height shall be based on the uppercase letter "I".
Table 18.9.4.7 Visual Character and Graphic Symbol Heights Based on Height and Distance
| Height of Character or Symbol Above Ground or Finished Floor | Horizontal Viewing Distance | Minimum Character or Symbol Height | |||||
|---|---|---|---|---|---|---|---|
| in. | m | ft | m | in. | mm | ||
| 40 in. min. to ≤70 in. | 1.02 m to 1.78 m | <6 | 1.83 | 5/8 in. | 16 mm | ||
| ≥6 | 1.83 | 5/8 in., plus 1/8 in. per foot of horizontal viewing distance beyond 6 ft | 16 mm plus 3 mm per 0.30 m of horizontal viewing distance beyond 1.83 m | ||||
| >70 in. to ≤120 in. | 1.78 m to 3.05 m | <15 | 4.57 | 2 in. | 51 mm | ||
| ≥15 | 4.57 | 2 in. plus 1/8 in. per foot of horizontal viewing distance beyond 15 ft | 51 mm plus 3 mm per 0.30 m of horizontal viewing distance beyond 4.57 m | ||||
| >120 in. | 3.05 m | <21 | 6.40 | 3 in. | 75 mm | ||
| ≥21 | 6.40 | 3 in. plus 1/8 in. per foot of horizontal viewing distance beyond 21 ft | 75 mm plus 3 mm per 0.30 m of horizontal viewing distance beyond 6.40 m | ||||
All characters and symbols displayed by textual and graphical visible notification appliances shall be a minimum of 40 in. (1.02 m) above the ground or finished floor.
Stroke thickness of the uppercase letter "I" shall be minimum 10 percent and maximum 30 percent of the height of the character.
Tactile appliances shall be permitted if used in addition to audible or visible, or both, notification appliances.
Tactile appliances shall meet the performance requirements of ANSI/UL 1971, Standard for Signaling Devices for the Hearing Impaired, or equivalent.
Where required by the enforcing authority; governing laws, codes, or standards; or other parts of this Code, annunciators, information display systems, and controls for portions of a system provided for use by emergency service personnel shall be designed, arranged, and located in accordance with the requirements of the organizations intended to use the equipment.