Knowledge database

General scanning rules for spectral measurements

  • Proper measurements require temperature of 23 +/- 1°C (73 +/- 2°F), 40-60 % RH
  • Take some additional measurement before for internal warm-up
  • For multiple measurements, always start by performing a new calibration.
  • Check if the instrument is scratching target - if so clean the bottom of the instrument and if necessary use paper bar to lift ruler slightly up - be careful not to lift it too much.
  • Clean calibration plate (ceramic tile) before calibration. Be sure that instrument is not very cold or hot (store it in its recommended temperature). Check if an optical patch is free of artifacts and dust.



Do you doubt it makes sense?

Do few simple tests and learn more about your Instrument

Go to Instrument Inspector and register target - Calibration White Plaque - This is your Instrument calibration Plaque. In most cases, it is a white ceramic tile. Start to measure it just for tracking Instrument.

  1. Measure it 20 - 30 times - compare readings in Instrument Inspector 
  2. Place spectrophotometer in the fridge for while ( to reduce its temperature about 10 degrees, not to freeze it !) - remeasure calibration white plaque a dozen times, and observe how the measurements vary as instrument warms up within Instrument Inspector.
  3. To simulate dirty calibration plaque put on it a small piece of paper  - calibrate the instrument and remeasure Target with and with out this artificial dust. You may also want to try calibrating your instrument on any piece of white ceramic tile or porcelain... 

    Of course, it is a joke  — it doesn't have any sense but show only that Instrument doesn't recognize it's own plate and if it changed  (replaced with similar from another instrument or just dirty) no warning will be displayed.

    It was a real experiment where instrument accepted porcelain coffee cup as a calibration plaque. Can you imagine what are the readings after such calibration? 


    E-factor for the difference between properly calibrated instrument and calibrated on the coffee cup was above 7! Good porcelain! When your instrument becomes dirty or just Calibration Plaque is dirty you can expect 1-2 ∆E difference easily! 2 ∆E on Instrument means 10∆E on your workflow... To see such differences Instrument is not required... 

    To learn more how to measure calibration White Plaque click here.

  4. Instead of experimenting, trust the Instrument Inspector - we did the experiments for you. Our Targets are for a thorough analysis of how the instruments measure.

    Take a closer look at Target types - unfortunately, we have not been able to create a perfect solution today. The requirements of one instrument are in conflict with the requirements of another.

    The material that Target is made of is either moderately durable or in its specificity deviates from real applications (in the printing industry we do not measure ceramic tiles only printing and this easily fades)

    To learn about Instrument Inspector Targets click here.