Key Principles of Laser Marking and Implications for DPM Code Quality

Cognex 8072V handheld barcode verifier

Laser marking is a non-contact, fast method of applying marks permanently on metal or plastic surfaces. While there are other methods of applying semi-permanent marks like chemical etching, ink-jet printing, and dot-peening, lasers are the most popular method because they are non-contact, require no consumable materials, and are permanent. Laser marking uses a concentrated wavelength of light, known as laser light, to permanently change the contrast on specific areas of a surface into a ‘mark.’ One of the most common marks is a direct part mark (DPM) barcode.

Several variables can affect the quality of a laser-marked barcode, including wavelength, material (or substrate), marking type, and laser settings such as speed, pulse frequency, and power.

Choosing the right combination of laser type, material type, mark type, and laser setting is often a matter of trial and error. Having a verifier that grades to the AIM DPM standard is often a good way to ensure that your combination of variables will result in a readable mark.

A barcode verifier can help ensure that your DPM codes are marked correctly and in compliance with your specific industry’s quality threshold. In comparison to barcode readers, barcode verifiers are a superior measure of symbol readability because they normalize the range of performance among various types of readers, from camera and laser to handheld and fixed-mount.

DM8072V Codes

While a barcode reader is designed specifically to read codes, a barcode verifier:

  • Ensures data is formatted correctly
  • Confirms barcodes can be read by all scanners
  • Pinpoints the reason(s) why a barcode will not scan
  • Prints reports listing barcode grades to certify they meet industry standards

A reliable barcode verifier will also highlight what parts of your code are scoring poorly, as well as help identify changes that need to be made to your laser settings to correct and improve your barcode quality.

To learn more about the key principle of barcode marking and implications for code quality, download the whitepaper: Beginners Guide to Barcode Verification

Naomi Brown

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