Photoelectric sensors offer noncontact measurement

Edited by the Engineeringtalk editorial team Jul 19, 2007

Rockwell Automation's laser measurement sensors provide a noncontact solution for error proofing, inspection, positioning and measurement applications.

Recognising the importance of flexibility and value in control systems, Rockwell Automation continues to introduce new sensors that help make installations simpler while addressing the market's ever-changing needs.

With the three new laser measurement sensors, Rockwell Automation presents a noncontact solution for error proofing, inspection, positioning and measurement applications.

The new Allen-Bradley 45BPD and 45BRD photoelectric sensors are intended for industrial applications requiring noncontact inspection, positioning and measurement.

Completely self-contained in an IP67 enclosure, the sensors do not require any external control devices which add cost and require extra mounting space.

In addition, they use a class-2 laser that has a visible red beam spot - simplifying alignment in small-part detection and measurement applications.

Both are excellent solutions for a wide range of noncontact measurement applications requiring sensing range up to 300mm.

Typical applications include: distance measurement, part profiling, thickness measurement, error proofing, inspection, verifying material position, hole-depth, warpage and part positioning.

The 45BRD model can be set up very easily, by simply mounting the sensor such that the target is within its operating range.

The 0-10V DC output is scaled linearly over the sensor's 45 to 85mm range and there are no user adjustments, making it the easiest-to-apply laser measurement solution available.

The 45BPD, a more advanced model, is set up by mounting the sensor with the target within the sensing range (30 to 100mm or 80 to 300mm) and teaching the appropriate set-points for the application via convenient teach-in buttons on the top of the sensor.

For optimal application flexibility, the 45BPD offers both a discrete PNP output and a 4 to 20mA analogue output, which is automatically scaled between the "taught" set points.

The 45BPD also includes lockout features to prevent tampering with the set points, a control to disable the laser during operation and an averaging mode to smooth fluctuations for detection of rough surfaces.

The third in the new series, the 45CPD line of photoelectric sensors, is ideal for industrial applications requiring long-range detection - up to 6m - with a small beam spot and noncontact measurement.

Once again, these sensors are completely self-contained in an IP67 enclosure and do not require any external control devices which would otherwise add cost and require additional mounting space.

The 45CPD uses a class-2 laser for ease of alignment during the sensor setup but switches to a class 1 "eye safe" IR laser when in the normal operating mode.

Using the Teach-In buttons on the top of the sensor, it can be programmed for several operating modes depending on the application, such as: object position (analogue output), object detection (single or dual discrete output) and background suppression.

Set up is quick and easy and is achieved by mounting the sensor with the target within the sensing range and teaching the appropriate set points using the Teach-In buttons.

For optimal application flexibility, the 45CPD can be set with either one or two discrete PNP outputs and a 4 to 20mA analogue output, which is also automatically scaled.

The 45CPD is an excellent solution for several long-range, noncontact measurement applications including: error proofing, inspection, distance measurement, verification of material position, stack level, thickness measurement, roll diameter, web winding/unwinding, long standoff distance (hot or limited space), level monitoring and box width measurement.