Maintaining the correct level of tension on web materials is critical to ensure quality and minimize material breakage, wandering, and other process issues that can lead to unplanned downtime.
Measuring roll diameter is fundamental to maintaining the correct amount of web tension. Variations in materials, material color, translucence and reflectivity, and environmental conditions can challenge a sensor’s ability to detect and measure these targets.
Banner provides a range of sensing technologies capable of accurately and consistently measuring roll diameter to ensure the correct level of web tension.
Accurate roll diameter measurement and monitoring controls tension by enabling dynamic adjustment of wind and unwind speeds proportional to the change in the size of the roll. This protects materials from damage due to too much or too little tension. However, monitoring roll diameter accurately can be challenging, since this application requires an extremely linear output across the entire range of the sensor.
Linearity refers to how closely a sensor’s analog output approximates a straight line across the measuring range. The more linear the sensor’s measurements, the more consistent the measurements across the full range of the sensor. That is, the more linear the sensor, the more the output shows the correct change along a line of measurement.
In the image to the left, the two-point teach option on the LE laser sensor is used to teach a full (4 mA) and an empty (20 mA) roll. The analog output provides a real-time gauge of the roll diameter. The more linear the sensor is, the more reliable the measurements between a full and and an empty roll. With perfect linearity, half of the roll would be gone when the sensor gives 12 mA. Sub-millimeter linearity is critical for reliable roll diameter monitor for tension control applications.
The LE series linear array technology provides great performance and resolution regardless of detection objects color or sheen.
Versatile, rugged laser distance sensors offering superior performance and capable of detecting sub-millimeter changes in distance.