Grapho Metronic FM19 - Measurement problems

cementary

Well-known member
We have 6 printing presses equipped with FM19 densitometers. Some of the those densitometeres randomly fail on measuring colorbar if the colorbar starts with 50% Cyan, 50% Magenta or 50% Yellow (System Brunner colorbars)
We've tried to address this issue: upgraded firmware for all heads (so they are same), installed same colorpilot soft
Finally, a serviceman came some time ago — he calibrated all heads.

But the trouble is still exists and pops up randomly.
Do anyone have any idea where to dig?
 

RJ Litho

Well-known member
You have to start with a solid not a screen there cannot be any toning on edge of sheet if there is use white out in front of the solid bar. We have to do this on foil board all the time. Registration has to be good for these bars to read correctly. These scanners are a bit fussy everything has to be perfect. What does it say when you go into diagnostics it should tell you what the fault is after it fails to read. let me know

RJ
 

cementary

Well-known member
It doesn't says anything. Just shows wrong measurements. Like if you put different sheet with different colorbar
 

RJ Litho

Well-known member
I am assuming you do strip search at the start of setting up the scanner. We had this issue to day.The operator put in the unit positions blk 1 cyan 2 mag 3 yellow 4 special 6.for some reason it switched the cyan to 6 and the special 3 once I put it back it was ok. I mentioned these scanners can be fussy.
RJ
 

cementary

Well-known member
Yes, we do strip search but in a "semiauto" mode. Which means we adress certain ink zone to search for. Full auto colorbar search never work reliable enough. Not only scanners are fussy. Firmware and colorpilot app itself are fussy and unstable too
 

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