Une nouvelle génération d'une technologie éprouvée, c'est le sujet de cet article publié dans le Aluminium Journal dans l'édition du 6 mai 2025.
GLS 4.0 - Molten Metal Level Control
General description
The GAP Level Sensor is designed to measure the metal level in molds and allows an extremely precise casting regulation despite the high-temperature present near a melted metal.
The system consists of a suitable measuring head fixed on an electrical lifting jack. The latter is equipped with an incremental encoder for distance measurement with 2 limit switches. This setup brings a wide range of precise measurements.
The electronic collects the signals, transmits the calculated value of the metal level to the casting machine and ensures that the head movements avoid any metal collisions.
The calibration is easy enough for the customer to execute themselves. With our modernized electronics, this operation is even more straightforward and user-friendly.
This new electronic device was designed to ensure long-term longevity, building on the legacy of our earlier GLS series—some of which have operated continuously for 15 years. In a time when many components quickly become obsolete, we have carefully chosen every part of this new generation to maximize durability and extend the product’s life.
Measurement
The head has a measuring range of 40 mm, and the lifting jack has a 200 mm travelling range. This offers a total measuring range of up to 240 mm.
The signal provided therefore corresponds to the sum of the value measured by the head and the distance between the head and its maximum top position (given by the encoder and the upper limit switch).
As in earlier versions of the device, the electrical analogue output signal works inverted. This means that the zero corresponds to the maximum metal level.
A digital output (NC) shows that the temperature is within tolerance.
Movements of the head
This movement is autonomous and optimized to retain the value measured by the head as close as possible to the measuring range (20 mm).
As long as the value measured by the head is within the margins of 10 mm to 30 mm, no motion occurs. This is to prevent an excessively large number of movements, something especially useful during the continuous phase, where the metal level variations are extremely small.
The output signal is continuously calculated with the sum of the measured signal and the distance provided by the encoder.
Its value is always precise, independent of the direction of movement.
New features
As the industry is moving towards a more digitalized environment, we have equipped the new version of the GLS with a brand-new interface that combines the full retro-compatible outputs which our customers are already used to, with a new digital interface that can be used to connect the device to a computer or a PLC.
This interface brings novelty in the form of a new calibration system and new signals that can be used to monitor the device’s status. To prevent any damages to the device the temperatures of both the head and the electronic compartment are now monitored. This improves drastically from the on/off single-measure system that was used until now.
It also provides the user with various values, such as the number of movements or the serial number of the device facilitating maintenance tasks as well as traceability of the device for preventive and/or predictive maintenance.
We also designed a whole new fully enclosed electronic board that is more robust to both vibration and air impurities or any oil residues.
(Retro-) Compatibility & future
Many of our customers already rely on the GLS, and we offer maintenance and spare parts to extend the lifespan of their products by up to 10 years.
If extensive servicing is required, we can retrofit the necessary components without discarding the product—and most importantly, without altering the casting machine. This is made possible by our commitment to a pin-compatible design. The new version is engineered to be as durable as its predecessor while also simplifying and improving maintenance.
