Self-contained sensor for controlling flow and measuring level of aluminium casting

Citation

(2002), "Self-contained sensor for controlling flow and measuring level of aluminium casting", Aircraft Engineering and Aerospace Technology, Vol. 74 No. 1. https://doi.org/10.1108/aeat.2002.12774aad.016

Self-contained sensor for controlling flow and measuring level of aluminium casting

Keywords: Sensors, Aluminium

LMI Selcom has recently introduced a new Classll single point industrial sensor to its SLS 5000 series designed to deliver real-time information on the actual level of molten metal in aluminum cast houses.

Like the other sensors in the line, the new Classll SLS 5325/1400 sensor is reported to provide exact and reliable level measurement of molten aluminum in the launder, assuring a consistent pouring level to reduce spillage and maintaining quality from startup to the finished product. By controlling the launder level, casting quality is improved, scrap consumption reduced, and productivity improved (Plate 7).

Reliable level control requires a sensing solution capable of providing accurate real- time information on the actual level of the molten metal. In aluminum casting applications, the sensor typically supplies data to a PLC control system, which controls the actuator pin position to assure a consistent flow and pour rate. The SLS 5325/400 is said to provide highly accurate and repeatable level information over a long measurement range resulting in optimum control of the flow rate with minimum exposure to hazardous conditions. Well protected inside an air- cooled heat shield, the sensors are reportedly insensitive to the "unfriendly" cast house environment.

Plate 7 The Class II SLS 5325/400 sensor

Based on the principle of laser triangulation, the sensor has a totally integrated sensor within the head and a built- in processor for data averaging and filtering. A novel dynamic laser feedback loop reportedly allows accurate measurement without regard to color, ambient light changes, speed and temperature of material or general plant environmental conditions.

LMI asserts that this characteristic allows the sensor to make virtually error-free measurement with total reliability and repeatability up to 16,000 times a second within a small defined spot using little power.

Designed for optimum flexibility, it requires only a single 24 Volt DC power source and provides data in both standard 0-20mA or 4-20mA analog and RS-232 digital outputs.

Other features claimed of the new SLS 5325/400 series sensors include a high speed resolution within an accuracy of ±0.2 per cent of the measurement range, a data sampling rate of 16 kHz, a band width (response) of 2 kHz and a stand-off distance of up to 300 mm. Each SLS 5000 sensor is factory calibrated to provide linear measurement output.

The SLS 5000 sensor for aluminum has a measurement range of 6.0 to 325 mm and stand-off range of 400 mm. Dimensions of the unit are 105 by 135 by 51 mm and weight is 1.0 kg.

The sensor is enclosed in a NEMA-4 (IP 67) aluminum housing for optimum air tight sealing and protection from moisture and dust in virtually any type of industrial application. The sensor's flat front also allows easy cleaning of the optics.

Details available from: LMI Technologies, Inc., Tel: +46 (0) 31 336 25 42; Fax: +46-(0) 31 44 61 79; E-mail: johan.ahlgen@lmint.com;Website: www.lmint.com.