The Balluff Case Study Series are texts showcasing real situations tackled by our specialists. They develop and implement dedicated solutions for production companies, with the use of Balluff products.

Case Study | Rooftop deflection control in an industrial hall


The weight of a cubic meter of wet snow overlying rooftops of halls or other large-scale buildings may add up to as much as 800 kg. It is a massive weight, whose untimely removal may lead to the collapse of the whole construction. Such situation entails not only material losses, but may also have legal consequences.

Rooftop deflection monitoring will allow to prevent hazardous situation from occurring, thus avoiding unforeseen expenses.

Initial situation

A Scandinavian doors and windows producer (construction woodwork sector), with a dozen or so large-scale halls, asked us to propose a solution that would automatize the rooftop deflection monitoring process.


The greatest problem in wintertime was checking the snow layer on flat rooftops of production halls. Up until now, this was performed manually: selected employees would climb on the roof in order to determine whether it was necessary to call in a snow-removing company.


We proposed using a road driver whose task was to provide absolute measurement of the linear position of the roof’s supporting structure in relation to the building floor. The implementation of this solution took some 2-3 days. The sensitive deflection points of the roof construction have been equipped with measurement systems containing BTL7 road driver sets, a contactless magnet, and a digital display.

We used:

  • BTL7-P511-M0050-P-S32,
  • BTL5-P-5500-2,
  • BKS-S 32M-00,
  • BDD-AM 10-1-P,
  • BAE PS-XA-1W-24-025-002.

The BTL in the installed application indicates current deflection of the rooftop construction. In the case that optimal indicators have been exceeded after a heavy snowfall, the technical crew directs a shoveling team in order to prevent construction damage and the resulting catastrophe.

The greatest advantage of this solution is the BTL7 road driver itself, which can work in a broad range of temperatures from -40 to +85°C and ensures high measurement accuracy. The device is resistant to weather conditions, high levels of humidity and dust, so commonly observed in industrial settings.

How does it work?

The solution monitors roof deflection in an efficient way. As soon as the layer of snow becomes too thick, the monitoring unit generates an alarm signal and sends it to the people responsible for monitoring. This way, in a situation that requires action, technical crew has the necessary time to react.

monitoring Balluff

Currently we can control these parameters online. We can also set alerts for the moment of surpassing allowable deflection level – all it takes is connecting road drivers to a CMTK module.
The user will receive an email alert or will see a flashing signal. Such solution allows for controlling many objects simultaneously – all from the same point or computer.

Benefits for the client

Constant monitoring of rooftop deflection allows for a direct remote control over the situation. When the snow layer is not big, it is not necessary to use the services of shoveling companies. This brings about savings on winter maintenance of industrial buildings.

However, the greatest benefit is the factual avoidance of rooftop and building construction damage, and therefore, avoiding disaster.

Where can this solution be applied?

Our solution may be applied to any industrial facility with a large-scale usage area and steel rooftop construction. It is also useful for controlling the position of bridges and drawbridge ramps, lifted either by a mechanical or a hydraulic system.

If you are facing similar problems to the ones described in the article or if you wish to improve production processes in your company, don’t hesitate to contact us.

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