Product Categories
AUDIBLE
SIGNALING DEVICES
Industrial Horns/Sirens/Sounders

Pfannenberg Audible Signaling Devices

Industrial Horns/Sirens/Sounders

Horns and sirens, also known as “sounders”, are tone generators that output an audible signal when a voltage is applied to their input power terminals. Sounders are self-generating – meaning that the tones are pre-programmed into their circuitry and the sound is simply emitted when power is supplied.

Sounders are widely used for generating evacuation alarms in the event of fire, toxic gas leak, or chemical spill. Other applications for sounders include machinery start-up alarms, back-up warning systems, process upset signals, heavy equipment movement, moving roof systems, crane movement, and movement of doors, gates, and barriers.

Sounders typically generate a variety of tones that can be user-selected. Some units are capable of delivering multiple tone stages. For example, one tone stage may signal evacuation, while a secondary tone stage may signal “all clear” or OK to return.

Why Choose Pfannenberg Audible Signaling Devices?

Great Acoustic Penetration

100 dB (A) to 120 dB (A) nominal sound pressure level and superior coverage.

Selectable Audible Notification

Up to 80 pre-programmed tones and 4 different events

Operates in Harsh Environments

Pfannenberg offer sounders which are suitable for use both indoors and outdoors and are adapted to all industrial requirements.

10 Year Warranty

Pfannenberg’s audible signaling devices include a standard 10-year warranty, guaranteed to protect men, machines and the environment.

Audible Signaling Devices Models

3D-Coverage – Spatial Performance for Audible Notification

The perception of acoustic signaling devices is determined by many factors. In particular, ambient noise and the use of hearing protection must be taken into account. This can be done with Pfannenberg’s 3D-Coverage  method which takes advantage of effective performance in a given space rather than relying solely on nominal output data presented in typical specifications.

The goal of 3D-Coverage is to provide a visual representation of the effective range of the signaling device, lending justification to its successful implementation in the defined space. Using Pfannenberg’s 3D-Coverage method,  planners are now able to determine the actual effective coverage area for audible and visual signaling devices.

Ambient noise can influence safety



Whether or not the audible signal from a sounder is successfully perceived is not just dependent on the output sound level generated and technology used to create the alarm signal. Ambient noise levels and sounder placement location are crucial elements that should not be overlooked.

The adjacent example illustrates the effect on coverage volume of an 100 dB(A) audible signaling device due to a 10 dB(A) change in ambient noise level. Increasing from 75 dB(A) to 85 dB(A) shows that the warning signal will not be successfully perceived.


The 3D-Coverage values show that the effective covered area is significantly reduced when the ambient noise level rises.

If the alarm system designer does not take all aspects into consideration, the consequences can spell danger for people in the surrounding area.

Practical example: PATROL PA 1  Sounder

SOUNDERAMBIENT NOISE LEVELAREA L x W x H ft (m)3D-COVERAGE ft³ (m³)
PFANNENBERG PATROL
PA 1 105 dB(A)
65 dB95 (29) x 82 (25) x 95 (29)740,050 (21,025)
70 dB52.5 (16) x 46 (14) x 52.5 (16)126,787 (3,584)
75 dB29.5 (9) x 26.2 (8) x 29.5 (9)22,800 (648)
80 dB16.4 (5) x 13 (4.5) x 16.4 (9)3,496 (113)
85 dB9.8 (3) x 6.6 (2.5) x 9.8 (3)633 (23)

The figures shown are mainly for a quick orientation. For an individual and precise interpretation please use PFANNENBERG SIZING SOFTWARE (PSS)