Application > Tube detection in heat treatment process

Tube detection in heat treatment process

Type + Article-No.:

LAB 600.3, 5038C
LSB 600.38 GV, 5037E



Non-contact detection of metal objects

Industry Steel industry – tube mill – production of cold-drawn seamless tubes

Customer / Field / Equipment manufactuer

Production of high-performance cold- drawn tubes for hydraulic cylinders for use in earth moving machines.

Application description

In order to comply with the relevant high standards, seamless tubes undergo heat treatments in controlled chemical atmosphere. Tube position at entrance and exit of the heat treatment furnace must be checked. Sensor is installed in a suction hood.

Customer problem

Tubes of medium and small size (diameter 30 mm) are treated. At the furnace entrance, thick smoke comes out of the tube, due to the tube movement and to the suction force. In this highly contaminated environment common light barriers are not able to detect the tube properly.

Previous solution / Competitor product

Tests with common light barriers from Sick and IFM had failed: smoke itself caused a light beam interruption, so that a tube tracking inside the furnace was not possible.

Proxitron solution

Thru-beam light barriers of the 600 series, with high functional reserve, and additional tube OL 21 for light beam narrowing.

Advantages compared to previous solution or competition

Having a powerful intensity, transmitter light beam can penetrate the smoke. A tube reducing the light bundle was added on the sensor head for the detection of small sized tubes (30 mm dia.); this makes it possible for small objects to interrupt a powerful light beam.

Accessories used


Mounting base
Tube for narrowing the light beam


HM 2
OL 21



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