Technical Specifications
The document provides technical specifications for the APD series electronic sounders by Kroma mec S.r.l. These sounders are designed for high power and low current consumption, certified under the ATEX standard EN60079. They are suitable for environments requiring alarm systems, especially where there is a risk of explosive atmospheres.

Voltage and Current
The sounders operate at various voltages: 24VAC/DC, 115VAC, 115VDC, 230VAC, 48VAC, and 48VDC, with a rated current of 1.6 - 3.8 A at 24V AC/DC.

Temperature and Protection
The working temperature ranges from -20°C (-40°C) to +60°C, depending on the model (T3/T5 or T4/T6). The devices have an IP66 protection rating, ensuring resistance to dust and water.

Sound Levels
The sound power levels are 114/117 dB at 1 meter and 104/107 dB at 3 meters. The sound distribution is illustrated in an outdoor loudness distribution polar diagram.

Materials and Construction
The sounders are constructed from low copper content aluminum alloy, featuring an electronic modular circuit and resonance unit. The sound is amplified by an external exponential aluminum trumpet.

Sound Options
The APD series offers five different sound types: two-tone (550Hz/0.1sec + 440Hz/0.4sec), monotonous (550Hz), yelp (fast ramp from 600 to 1550Hz), wail (slow ramp from 600 to 1550Hz), and periodic intermittence (550Hz 1s ON / 1s OFF).

Mounting and Accessories
The sounders are mounted using a stainless steel 316 bracket. Additional accessories and epoxy coating in various colors (yellow, blue, grey, black) are available upon request.

Certification and Zones
The sounders are explosion-proof, suitable for zones 1, 2, 21, and 22, with temperature classifications T3/T5 (up to 100°C) and T4/T6 (up to 85°C).