InGaAs Sensor Selection for Foreign Matter Detection
Select standard InGaAs for cost-effective detection up to 1700 nm, or cooled extended InGaAs to capture 2200 nm polypropylene combination bands cleanly.
Tungsten Halogen Lights
Broadband Emitter
Incandescent lamps containing a halogen gas provide a continuous spectrum of light across the visible and near infrared ranges. These tungsten halogen lights are frequently used in textile laboratories and inspection machines because of their high color rendering index. The presence of the halogen gas allows the filament to operate at higher temperatures without darkening the glass envelope.
This results in a stable light source that is ideal for color matching and fiber identification.
Color Rendering
Accurate perception of fabric hue depends on a light source that contains all the wavelengths of the visible spectrum. Because tungsten halogen lights mimic the spectral profile of natural sunlight, they are the standard for evaluating dye consistency. These lamps are used in viewing booths to check for metamerism, where a color looks different under different lighting conditions.
Consistency between the mill and the buyer depends on using these standardized sources.
Thermal Stability
Radiant heat is a byproduct of the high temperature filament. When using tungsten halogen lights in an inspection system, the housing must be designed to manage this heat to prevent damage to the fabric or the camera sensors. The lamps require a warm up period to reach their full operating temperature and spectral stability.
Frequent power cycles can shorten the life of the filament.
Laboratory Standard
Reference instruments for measuring the reflectance and transmittance of textiles often rely on these lamps. The predictable output of tungsten halogen lights makes them suitable for calibrating spectrophotometers. While led technology is becoming more common, these lamps remain the benchmark for broadband infrared applications due to their smooth and continuous emission curve.