• Type of protection: intrinsically safe EEx ia I
• Switchable dialling mode (DTMF, PD)
• With loudspeaker for loud distribution of the call signal and alarm announcements
• Fully compatible and combinable with the previous model iVT1
• Variable power supply by:
  • primary batteries
  • local feed with battery backup
• Two independent, intrinsically safe output contacts for actuation of additional acoustic or optical secondary ringers
• Emergency call button with programmable function
• In conjunction with the telephone couplers iKT1(on the surface) or KT1 (underground) providing of a complete, intrinsically safe telephone network according to the lastest
• Ex-protection standards (EEx ia I)
• Variant with separate batteryand terminal housing available
• Function keys with special functions (programmable by the user)
• Signalling key with flash function
• Assignment of a fixed digit sequence to a key
• Short dialling of up to ten phone numbers (programmable by the user)
• Simple adjustment of all important parameters by the user on the site without opening the housing
• Possible user-guided parameter adjustment via terminal
• Keyboard easily changeable as a module on the site
• LF interface for further transmission of alarms and announcements into intercom systems

The iVT2 alarm telephone is the successor of the iVT1 and is used in intrinsically safe telephone systems or alarm telephone systems in the coal mining industry.

A highly efficient microprocessor of the latest generation permits many functions such as switchable dialling mode (DTMF, PD) and other functions already known from intelligent office phones.

The built-in loudspeaker serves for loud distribution of call signals and alarm announcements. Power is supplied by primary batteries or local feed with battery backup. Reliable telephoning and alerting is thus possible even if the main power supply is switched off because of higher CH4 values.

Intrinsically safe circuits can be switched via two potential-free contact outputs for additional visualisation of the call signal and/or the alarm signal.

The casing of the iVT2 is made from glass fibre-reinforced, conductive plastic. It is light, corrosion-resistant, rugged and offers environmental protection according to IP 54. The hinged cover can easily be opened. The iVT2 is fixed to the wall by use of three straps.

All functions of the iVT2 alarm telephone such as hook-up, dialling, disconnect, idle state, etc. are monitored or controlled by built in microprocessor. A complex operating program monitors the keyboard and battery charge and operates a non-volatile memory (EEPROM). This memory retains all the information stored in even after power supply is disconnected. The user can thus adapt the alarm telephone to the local operating conditions without changing the program.

An alarm telephone system according to EEx ia I can be installed with iVT2 alarm telephones, iKT1 telephone couplers and the alarm computer (ATAR).By means of this alarm telephone system rapid and selective information or alarm announcements can be transmitted to persons. For example, the underground personnel endangered by gas outbursts or fires can be warned in short time and/or informed of escape routes.

The alarm announcements can be iniciated by a supervisor via microphone or by permanently pre-stored texts at the touch of a button by operation of the alarm processor. The announcements can be given to an individual alarm telephone, to various groups (max. 99) or to all employees (max. 960). The alarm processor additionally monitors line condition and battery voltage.

An emergency telephone in the central control room can be called automatically by pushing the emergency call button integrated in the iVT2 telephone. All system activities can be displayed with date, time and telephone number on the screen, are recorded by a printer and stored on the fixed disc.