### AIM DPM/ISO 29158 Verification Tool Parameters

##### Verification Settings

Click the Verification Settings area of the parameters to bring up the controls for Aperture, Lighting, and Setup Notes.

- Lighting Wave Length specifies the wavelength of the lighting being used. Note that this value is for reporting only and does not affect verification results.

- Lighting Angle specifies the angle of the lighting being used. Note that this value is for reporting only and does not affect verification results.

- Setup Notes allows you to record any additional information that needs to be considered about your camera or lighting configuration.

Precautions for Correct Use: AIM DPM/ISO 29158 automatically determines and reports the aperture per the specification to either 50% or 80% of the nominal cell size of the symbol under test.

##### Calibration

Click the Calibration section of the parameters to bring up the dialog shown below. The Calibration dialog features simple instructions about how to calibrate your camera and the Verification Tool in order to be compliant with your chosen verification specification. You must have a Calibration card in order to calibrate your system.

Use this dialog to enter the data from your Calibration card, and then click the Calibrate Reflectance button to start the process.

As part of the calibration process, the Exposure Time setting of your camera will be adjusted. Use the Maximum Exposure value in the Calibration dialog to set the maximum Exposure Time that can be set.

Precautions for Correct Use: Verification tools must be calibrated first to achieve accurate results.

##### Custom Verification

When you click the box next to Enable Customized Verification Tests, you will see the dialog shown below. This dialog allows you to select the individual attributes on which the verification will be based, and to define Good/Fair/Poor ranges for each attribute.

Precautions for Correct Use: Disabling parameters using the Custom Verification dialog results in a verification process that no longer strictly conforms to the AIM DPM/ISO 29158 standard.

AIM DPM/ISO 29158 Verification Parameters

- Cell Contrast: In AIM DPM/ISO 29158, the difference in the population of dark pixels to the population of light pixels, using the sample principle as “Symbol Contrast” with modified definition.

- Cell Modulation: In AIM DPM/ISO 29158, a measurement of the uniformity of the color of the dark areas and the light areas of the Data Matrix similar to “Modulation”, but differing in the implementation details.

- Reflectance Margin: A measurement of how well each module is correctly distinguishable as light or dark in comparison to the global threshold.

- Fixed Pattern Damage: A measurement of the errors in the borders of the Data Matrix as well as any errors in the quiet zone around the symbol necessary for the decoding process.

- Axial Nonuniformity: The difference between the height and the width with respect to the rows and columns.

- Grid Nonuniformity: A delta of the difference of the measured grid in relation to the ideal grid formed from the four corners of the Data Matrix.

- Unused Error Correction: The amount of error correction that could be read incorrectly when the symbol is still readable that is currently being read correctly, expressed as a percentage.

- Print Growth: The positive or negative size relation of the cells as printed with respect to the ideal grid.

- Minimum Reflectance: During “Card Calibration”, the NIST-traceable card is used to calibrate the system and to calculate a “calibrated system reflectance value”. During “Part Calibration”, a good example of the actual part is used to calculate an exposure time that optimizes the brightness and contrast of that symbol. During the Verification cycle, the calibrated system reflectance value is compared with the reflectance value of the part viewed with this adjusted exposure time. Parts whose bright symbol elements are less reflective than the calibration standard card will need more light energy for the camera to achieve the appropriate image brightness. Minimum Reflectance is the ratio of the part’s reflectance to the calibrated system reflectance. Every part must provide at least a minimum level of reflectance.