fiber optical multiplexers is used for basic transmission equipment, the transmitter is usually continuous uninterrupted working outdoor 24 hours whole day, and with environmental differences in different regional , greatly shorten the life of the device. While some engineering install the equipments, for various reasons, usually will add an equipment box externaly, and in the summer, the internal temperature reached almost 70 degrees, so when the multiplexer factories design the product, should fully consider the effect of temperature on its. 

When the multiplexer used in cold region, due to the machine itself continuous working will generate heat, so low temperature is not the main problem, while high temperature should be paid special attention. 

In view of the multiplexer’s high temperature adaptability , first, the electronic components should be conform to the standard , which can reach the limited of upper and lower temperature, those determines the multiplexer can withstand temperature range;Second,when production, can increase ventilation on both sides of the fuselage , to ensure the device ‘s internal air convection. Finally, aging security system. Our company has various multiplexer, such as SDH fiber optical multiplexer, FXS/FXO/POTS/E&M/Phone voice fiber optical multiplexer,those devices will have 48 hours continuous aging operation, that is, in the indoor environment, artificial control the devices in harsh environments aging guarantee, through baking device, small defected products can be found. 

Because of the transmission signa is different, can integrate a variety of different types of interface (such as video, audio ,data interface etc.), so manufacturers also should consider the port protection when design the devices. 

Our company mainly using the way of lightning protection to protect the interface, because in the summer too much thunder and lightning, and unpredictable, so different ports has different forms of lightning protection, increase protection circuit or lightning protection chip etc. TVS diode can be used for video port, or increase the Anti-static mat, can reduce the damage probability of the thunder and lightning.

Lightning is not a one-off completely discharge, but through the three levels of lightning protection, the first level lightning protection mainly for 10 kv high-voltage, can add the lightning protection device on the outside of the fiber optical multiplexer; The second is for hundreds volts, can install lightning protection material in the equipment ; Last level is for lightning protection for fiber optical multiplexer itself, in the inside integrated lightning protection chip, can protect above 6 kv lightning, through the three levels of lightning protection, can be minimize the risk of lightning strike for SDH fiber optical multiplexer, FXS/FXO/POTS/E&M/Phone voice fiber optical multiplexer and so on.

Following is the pictures of fiber optical multiplexer: