Size reduction for UV sensor due to remote sensing

Edited by the Engineeringtalk editorial team Apr 19, 2006

Remote ultraviolet luminescence sensor combines small size with long range, high resolution and ease of use in demanding applications.

EMX Industries has introduced the UVX-300G-REM, the first remote ultraviolet luminescence sensor that combines small size with long range, high resolution and ease of use in demanding applications.

The remote sensing head is easily mounted and measures 1.8 x 2.0 x 3.0cm, a volume of less than 11.5cm3, claimed to be 87% smaller than previously available UV sensors of this type.

The sensor provides high sensitivity and long-range target detection.

The size reduction, achieved via remote sensing, allows the sensor head to be positioned near rollers and spray nozzles, while its long detection range allows positioning away from debris contamination and physical damage.

It is suitable for detecting adhesives applied in assembly, manufacturing and packaging operations.

The output of the remote sensor head is connected to a control unit through a 1m cable.

The sensor control unit provides a visual readout and sends signals (0-5V analogue and discrete on-off) to a master controller through a separate cable.

As part of a feedback control loop, it can precisely measure the amount of applied adhesive, check for the presence of a material or part, and alert operators to problems such as misapplication, omitted items and improper equipment operation.

UV sensors can detect the presence of seals, adhesives and other assembly components for quality assurance and manufacturing process feedback.

Glues and other materials that are not naturally luminescent can be made UV light responsive by sensitising them with additives or markings, without affecting the manufactured product's appearance.

Because UV sensors can easily discriminate targets in any orientation from similarly coloured backgrounds, they can be more reliable than expensive vision systems.

Its high sensitivity lets it detect subtle differences in assemblies and packages, and is adjustable for different materials.

It can even detect transparent materials.

The control unit provides five user-selectable gain settings and relative reflection readings from 0 to 99.

It allows adjustable light projection (370nm UV LED; minimum life of 100,000 hours) and its high resolution delivers pinhead accuracy.

Users can set the detection threshold, but a lockout feature prevents unauthorised adjustments.

It extends the useful operating distance of UV sensors to 350mm.

For optimal machine control, it has a feedback response frequency of 6kHz.

This is important in glue dispensing machinery, which often operates at high speeds and has applicators that are subject to clogging.

A sensor with slow response time can miss gaps in adhesive application and have a negative impact on product quality.

Because UV luminescence is invisible under normal lighting conditions, UV sensors are difficult to tune without some indication of what they are reading.

The UVX-300G-REM solves this problem by providing a numerical readout of the detection threshold and relative reflection intensity of each reading.

This feature makes it easy for an operator to tune the sensor and saves valuable engineering time.

It includes both auto-teach and manual calibration.

This makes it easy for operators to fine-tune and calibrate the sensor without any special training.

The 0-5V analogue output provides a measure of reflected UV intensity, and its 20mv resolution allows the tracking of process variations for SPC and SQC applications.

LED indicators for power, programming and detection functions aid in setup and troubleshooting.

The control unit has an IP67-rated housing suitable for various operating environments, plus short-circuit, overload and reverse polarity protection.

Connections are made via a standard M12 five-pin connector.

Optional accessories include mounting brackets, and a 5m control unit cable with an M12, five-pin connector.