Metal Keypad and Vandal Resistant Auto Dial Telephone for Hallways, Airports and Malls

Application Conditions

Environment Temperature: -10~+50

Relative Humidity: 45%~95%

Atmospheric Pressure: 86~106Kpa

Environment Noise: 60dB

Main Technique Data

Work Frequency: 300Hz ~ 3400Hz

Buzzer Level: 70dB

 DTMF Dialing                (Dual Tone Multiple Frequency)

Low frequency group frequency: 697.770.852.941Hz

High frequency group frequency: 1209.1336.1477Hz

Frequency Deviation: 1.5%

Level of low frequency group: -9±3dB

Level of high frequency group: -7±3dB

Level difference between high and low: 2±1dB

Total distortion of harmonics wave lower than  Fundamental wave leve: 20dB

Electroacoustic Characteristics

                              0Km       5Km

Sending loudness rating (SLR)    +5dB    +15dB

Receiving loudness rating(RLR)   -7dB    +2dB

Sidetone masking rating(STMR)   +6dB    +12dB