The telecoms industry does a lot of work in confined spaces. Even simple above ground termination boxes can have gas hazards which derive from the cables runs underground. Gases such as methane, carbon monoxide and hydrogen sulphide can run through the cable trunking and emerge when the termination box is opened. The Senko MGT P is a good option for this type of application. The basic application is for people going underground (confined spaces) and for people opening up ducts at street level. The main first contacts would work in health and safety.
Another application is for fixed systems in “hub sites” and remote buildings. These are places where cables are terminated and junctions or take off points are put into the networks. SI-100 for methane and oxygen would work to provide constant monitoring in sites which are usually not attended. The danger comes when someone is sent to do work there and has to enter after a long period of the building being shut.. All telecommunications companies have these in abundance. Good first contacts are network Managers and operations managers.