Position of threshold in LUTM

10% on luminescence intensity card

30% on luminescence intensity card

75% on luminescence intensity card

200% on luminescence intensity card

As you can see the default threshold of the LUTM moves towards the background the bigger the contrast between luminescence target and background becomes.
The following picture shows the algorithm in a graphic:

What's the reason for this algorithm?

• In LUT applications you often have the case that the target has luminophores and the background has no luminescence. So the background signal is quite stable.
  → No risk in placing the threshold close to background.
• Additionally the luminescence intensity often varies in quite big amounts (more than 50% if the contrast)
  → A threshold close to the background ensures safe switching behavior.
• A lot of customers like to detect easy luminescence marks or other signs like a line made of luminescence crayon. Such customers often don't teach the LUT sensor.
  → Having a threshold close to background ensures also safe switching for those customers.
• In a lot of LUT applications the scanning distance varies. Variations in scanning distance result in variations in signal. 
  → If the threshold is close to background those variations have no influence.
• In most LUT applications no high accuracy is needed.
  → No need for a precise 50% threshold