Mine Emergency Assistance Fiber Optic Telephone Tunnel Intercom

I. Functional Overview
1. Wall-mounted installation, aluminum alloy die-cast housing with a wall thickness of not less than 5mm, offering strong vandal resistance.
2. Industrial three-proof design, waterproof and dustproof rating meets GB/T 4208-2017 IP68.
3. Supports connection to PSTN telephone lines and digital program-controlled switchboard networks.
4. Supports free dialing or automatic dialing upon off-hook.
5. Supports automatic answering of incoming calls and activation of broadcasting.
6. Supports external 30W speaker amplification and incoming call reminder warning light.
7. Supports busy tone detection for call termination.

II. Operation and Usage
1. Off-hook/On-hook method: Handset-controlled off-hook/on-hook; off-hook for connection, on-hook for disconnection.
2. Answering calls: When there is an incoming call, the telephone rings; pick up the handset to communicate with the caller, and hang up the handset after the call ends.
3. Making calls: Pick up the handset and operate as with a standard telephone to dial and communicate with the other party.
4. Amplified broadcasting: Automatically activates broadcast ringing, light reminders, and broadcast announcements upon incoming calls.

III. Main Technical Parameters
1. Supports connection to PSTN telephone lines and digital program-controlled switchboards with a feed voltage of 48V-60V.
2. Temperature: -40℃~75℃; Relative humidity: 10%~95%; Atmospheric pressure: 86~106 Kpa; Ambient noise: ≤100dB(A) 
3. Ringing sound level: ≥120Db 
4. Supports busy tone detection for call termination.
5. Built-in 30W amplifier circuit, external amplification speaker rated at 30W, and 12V incoming call reminder warning light.

IV. Packaging Dimensions
Unit dimensions: 339*246*126 (mm)
Outer box dimensions: 420*490*330 (mm)
Packaging materials: Pearl cotton, carton
Gross weight: 9KG
Net weight: 8KG

V. Support and Service
Under normal use, excluding human damage and natural disasters, 14 months free warranty;
All accessories are produced long-term and kept in stock. After the warranty period, we continue to provide product after-sales support.