# What problem occurs when single edge sensors face width changes?

> Manual Sensor Respositioning: If the web is guided to the centerline position using single-edge methods, the sensor must be moved for every width change, increasing setup time and complexity. Possible Operator Error: Physical repositioning relies on the operator to correctly locate the sensor rel...

**Last updated:** 2025-12-28

**Source:** https://live-roll2roll.pantheonsite.io/resources/faq/what-problem-occurs-when-single-edge-sensors-face-width-changes

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## Question

What problem occurs when single edge sensors face width changes?

## Short Answer

The width change necessitates manual repositioning of the sensor to the new edge location, which introduces several operational risks.

## Detailed Answer

- Manual Sensor Respositioning: If the web is guided to the centerline position using single-edge methods, the sensor must be moved for every width change, increasing setup time and complexity. 
- Possible Operator Error: Physical repositioning relies on the operator to correctly locate the sensor relative to the machine and securely lock it in position. Mistakes here can lead to misalignment. 
- Fork Sensor Issues: Conventional fork stype sensors could snag the web material if the sensor is not moved before the width change. And even after width change the sensor needs to be repositioned to ensure that the web is inbetween the two sensing arms. 

Legacy systems attempt to solve this with mechanical sensor positioners (moving sensor center guides or even moving a single sensor), but these introduce additional mechanical wear and tear. [Roll-2-Roll® Sensors](https://r2r.tech/products/sensors) solves this with sensors and adjusting the **electronic guide point** using [Roll-2-Roll® Controller](https://r2r.tech/products/controllers), eliminating the need to physically move the sensor when the web width changes. 

More importantly the [Roll-2-Roll® Sensors](https://r2r.tech/products/sensors) are single sided completely eliminating the possibility of snag or web threading issues during width change over. 

**Category:** General

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## About Roll-2-Roll Technologies

Roll-2-Roll Technologies designs and manufactures patented fiber-optic web position sensors and advanced web guiding controllers — the precision measurement and control core of modern roll-to-roll manufacturing. Spun out of Oklahoma State University's Web Handling Research Center and trusted by Fortune 500 medical, battery, and nonwovens manufacturers, our patented sensors work without recalibration at ±0.1mm accuracy up to 760 mpm — typical customer outcomes are 50%+ less downtime and payback under six months. Headquartered in Stillwater, Oklahoma, our team of PhDs, controls engineers, and industry veterans extends the sensor + controller core into complete web guide systems including stepper-motor-based linear actuators (RLA, BLA, LHS).

- Website: https://r2r.tech
- Phone: +1 (888) 290-3215
- Email: sales@r2r.tech