Threshold - QVI Cobra DRS-300 User Manual

Set the maximum exposure value based on the reflectivity of the part surface.
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Note: If data is missing as you scan (data drop outs), increase the maximum
exposure. If not, try decreasing the maximum exposure to increase your scan
speed when the length of time for a scan is an issue.

Threshold

This control sets the laser threshold. The threshold value is represented by a red
line in the Sensor Settings window. Data below the bar is eliminated from the
evaluation and data above the bar is included.
The sensor spot height calculation algorithm disregards pixels with light
intensity below the threshold value. Use the threshold value to eliminate the
effects of unwanted signals, such as secondary reflections.
The threshold value can be set to any integer value between 10 and 255; the
default is 50. Typically, you should set the threshold as low as possible without
including secondary spots above the threshold bar in the Sensor Settings
window. Settings that are too low can produce unreliable data.
Note: The default threshold value (50) works well for most applications and
usually does not need to be adjusted.
Getting Started
For highly reflective part surfaces and/or specular sensors, use shorter
maximum exposure values.
For less reflective part surfaces and/or diffuse sensors, use longer maximum
exposure values.
If you scan a variety of surfaces, longer maximum exposure settings work
best, but may increase the total scan time.
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