Balluff photoelectric line sensor provides inexpensive edge and width measurement.

Balluff’s unique BOL 27K advanced measuring line sensor provides the most cost effective way to sense product width, edge detection, hole location, and web loop tension. With both discrete and analog outputs, this specialized retroreflective photoelectric sensor projects a measuring line of light onto a strip of special reflective tape, which it then uses to measure and locate key attributes of an object. The sensor’s 0.15 mm resolution makes it ideal for error proofing, sheet feed control, web control, and a wide range of packaging tasks.

The BOL 27K operates in three basic modes:


Edge Position Mode

Part Number	Description
BOL 27K-PS-L01-S115	PNP + 4...20mA
BOL 27K-NS-L01-S115	NPN + 4...20mA
Sensing Distance	200 mm
Sensing Area	150 mm
Sensing Function	Retroreflective
Output	Teach discrete and analog
Cable Part No.	C04 AET-00-PB-050M
Bracket Part No.	BOS 21-AD-1
Jointed Support Part No.	BOS 18-HS-1

Detects the position of an object passing over the tape – ideal for strip feed positioning of objects made of materials as different as paper or steel. This mode can also provide the distance from a hole to one of the edges of an object.

Width Detection Mode
Provides the distance between the two edges of an object, such as a pipe or a group of objects (stacks of blister packs). For objects that are more than 150 mm wide, two BOL 27Ks can be used in concert to provide the measurement.

Center Positioning Mode
Detects the center of an object independent of that object’s width.

	Detecting Edge Position Once the edges of the reflective tape are calibrated, the percentage of the tape covered by an object gives the BOL 27K an accurate location of the object’s edge without the need of feeler gauges or mechanical contact with the object.
	Measuring Object Width Once the length of the reflective tape is calibrated, the percent of tape blocked by the object gives the BOL 27K the width of the object. This provides a lower cost width measurement than can be had with a vision system.