Coatbridge, Scotland. With a large proportion of telecom infrastructure being located outdoors, it will regularly be exposed to adverse weather conditions. The threat of rainwater ingress is something that telecom companies need to safeguard against, as the damage that ensues can have dire consequences—resulting in prolonged service interruptions and costly repair work. Carrying out systematic inspections can often be difficult, due to the large human resources needed and the fact equipment may be located in remote places. To address the issue, SST Sensing now has a series of leak-detection sensors, based on its proprietary Optomax technology.

These compact, high-performance liquid level switch devices, with built-in microcontroller functionality, don’t have any moving parts. Instead they utilize a more convenient and reliable, yet inexpensive infrared (IR) sensing mechanism. The principle of this is simple, but effective—if a liquid comes into contact with the sensor tip it will change the properties of the optical setup, with light that was previously internally reflected being dispersed. Less light is thus incident on the device’s phototransistor, leading to change in the output voltage. Through this telecom operators/carriers can be rapidly alerted of the presence of water in their fiber-optic cabinets, base stations, pico cells, etc.

As enclosures are packed with cabling and electronics, there is only limited available space. The small form factor of the Optomax devices (which can be offered in an M10 housing, with a length of just 22.7 mm) makes them suited to this type of application setting. Supporting a working temperature range of -25°C to +80°C, these robust units can deal with severe fluctuations in environmental conditions and maintain long term operation. The IR-based approach has the capacity to deliver an elevated degree of sensitivity. This means that there is no delay in response and valuable apparatus is not thereby put at risk.

“The impact of leaks on networking equipment can be heavy, with the consequential downtime being harmful to the telecom company’s reputation and raising frustration for their subscribers,” explained Paddy Shannon, technical director at SST Sensing. “The implementation of our Optomax devices in this scenario is proving increasingly popular. Through only minimal investment, the ongoing functional integrity of vital telecom hardware can be assured.”

Liquid sensor devices from SST protect telecom equipment
Rick Nelson
Rick became Executive Editor for EE in 2011. Previously he served on several publications, including EDN and Vision Systems Design, and has received awards for signed editorials from the American Society of Business Publication Editors. He began as a design engineer at General Electric and Litton Industries and earned a BSEE degree from Penn State.