heavy duty telephone

1 Range Can be used in subway ,water resources scheduling,shipping ,shipping port ,railway tunnel and other rough area. 2 Feature 2.1 Shell of the explosion-proof telephone made of si-aluminium alloy with high temperature ,electrostatic plastic sprayed surface. High impact. Whole telephone of the waterproof grade is up to national standard GB4028-93IP67 2.2 The telephone adopt stainless steel keypad, which contact resistance below 30ohm,life cycle above 2 million,push force 160-200grams,defend grade is up to IP67, good hand feeling,sturdy and durable. 2.3 Handle adopts imported Pc engineer material, thermostability of the PTFE wire .military noise cancelling microphone.Clear conversation in 115 dB enviroment . Good tightness , Denfend grade is IP67. 2.4 Hook adopts magnetic induction switch, life cycle above 500 thousand 2.5 These electronic components of the product adopt famous imported brand and selected by high and low temperature aging test. telephone is provided with high stability, high anti-jamming capability, and it is up to national standard GB T 15279-2002 2.6 There are 12 groups superstrong function with srore ,memory,dial (Each number up to 16 ) 2.7 Easy for install and operate 3.Technical parameter Defend grade IP67Ambient temperature minus 40 to 70 degreeRelative humidity below 95 percentAtmospheric pressure 80 to 106 kpaFeed voltage 48 to 60 V Feed current 15 mACall transmission index SLR below 12 RLR below 1 STMR above10 output impedance 600ohms Frequency response 300 to 3400 HzLines output audio signal level 2dBAmbient noise below 115dBDistortion factor below 2 percentRinging sound levelabove 65dB installation wall-wounted