Explision-proof Emergency Call Box

Telephone system: dual-tone multi-frequency;
Incoming call ringing signal light prompt;
Call connection time: ≤ 6S (non-blocking);
Maximum communication distance: 5km;
Graded rated sound pressure level intensity: ≥ 90dBA;
Audio range: 300Hz ~ 3400Hz;
Harmonic distortion: ≤ 5%;
Support wall-mounted and floor-standing;
DTMF call system;
Rated feed voltage: DC48V/DC24V;
Send/receive frequency response: comply with GB/T15279-2002;
Transmit Loudness Rating (SLR): 5 ~ 15dB;
Received Loudness Rating (RLR): -7 ~ 2dB;
Sidetone Masking Rating (STMR): ≥7dB;
Interface: 2PIN terminal;
Ambient temperature: -20℃ ~ +70℃;
Use relative humidity: 10% ~ 95%;
Protection class: IP66;
Anti-static, waterproof, dust-proof, anti-corrosion sealed touch keys;
Dial keypad: 0 ~ 9 number keys, 3 function keys: tight call key, redial key, hang up key;
Off-hook automatic dialing, can be set to automatically dial the management center or emergency duty room;
Can manually dial out to 119/110 and other outside calls;
Dimensions: 362x285x168mm;
Weight: 7.8Kg;