Application:
1.metro
2.highway call box
3.power plant, steel plant
4.Refineries
5.mines
6.Dockside
7.other hazardous environment which has the demand of damp proof , fireproof , dustproof, freeze proof and anti jamming, especially for the place with big noise.

Description:
Defend grade: GB 4208 - 93 IP 66 / IP67
Call capability of phone: GB/T 15279 - 94
Application scope: metro, light railroad, speedway, ship, mine, etc.
External configuration specification:
External dimension: 320*205*120mm Weight: 7Kg
Installment dimension: 139*260mm

Features:
1. Cabinet: aluminum alloy die - casting, high anti - violent, able to glisten, convenient for looking for ( optional).
2. Door cover: adopt the stainless steel spring joint , orient automatically and good self - closing, with spring mounted inner door axis , the cover can auto flip back and the lock can be auto locked , additional lock can be mounted for better protection.
3. Handset: made of special engineering ABS plastic, high anti - knock resistance. high tensile strength resistance and high anti - violent.
4. All of the components including handset telephone receiver and transmitter, keypad, buzzer, circuit board and cabinet are designed to be multi - layer waterproof and dust - proof which is up to Class III grade. The whole machine has gained the certificate of national standard GB4208 - 93 IP 66
5. Phone is provided with high stability, high anti - jamming capability, there are moving coil and electret structure for microphone of handset with good noise cancellation effect, also with strong ring volume and signal lamp outside .The whole telephone is up to national standard GB/T 15279 - 94.
6. Ring volume enlarging function: For normal telephone, the workers in the plant have no way to hear the telephone ring in case of noise around over 90db, then leads to the product attemper dictate can??t be transmitted in time and affect economic loss. KNSP - 08 can solve this problem well with a 20W high voice loudspeaker connected. When used as call machine and under the condition of ring electricity being on, the telephone can auto open power source inside, enlarge the ring volume and give voice through the loudspeaker. At the same time it can auto count the ring times. After several times(the phone itself is set for 5times), the phone can auto dial, the calling side can broadcast and its voice can spread to the workers nearby or other maintenance workers through loudspeaker.
7. After the following condition being solved, the public - address system will stop.
A. caller stops before the ring times reach the set times (5 times).
B. Receive the busy signal or reversed polar signal from Core Switch after the caller finish the calling step.
C. Silence time over 80S while calling.
D. Someone pick up the handset and start the conversation
8. During the calling, the called side can also pick up the handset and start the conversation. The public - address system is auto closed.
9. The called side can also talk during the ring time.
10. The 24V power source will be closed automatically in no calling condition. Safe and credible.

Specification:
1. Applicable for various types of SPC exchange and dispatching exchange system with feeding voltage of 48-60V.
2. Ambient temperature:-30 ~ +60 degree Relative humidity:10%~95%
Atmospheric pressure: 86~106Kpa Circumstance noise:less than 60dB(A)
3. Sound level of ringing : can be set according to customer's requirement
A.>70Db    B. >90Db      C. can reach 120Db with a loudspeaker which output power is from 10w to 25w.
4. Standard frequency: low frequency group: 697. 770. 852. 941Hz,
high frequency group: 1209. 1336. 1477Hz, frequency deviation: -1.5% ~ +1.5%
If service line is a 3Km signal - level:
Standard frequency: low frequency group: -12dB ~ -6dB, high frequency group: -10dB ~ -4dB, level difference between low and high frequency of compound signal: 0dB~3dB, the total distortion caused by intermodulation of harmonic wave is lower than the basic level by at least 20dB.
5. Call transmission index:(5KM)SLR<12,RLR<-1,STMR>10, output impedance is 600 Ohm.