Re: Spectrophotometer accuracy
Re: Spectrophotometer accuracy
- Subject: Re: Spectrophotometer accuracy
- From: Robin Myers <email@hidden>
- Date: Thu, 25 Aug 2005 10:27:21 -0700
On Aug 25, 2005, at 9:56, Michael Fox Photography News Account wrote:
<x-tad-bigger>Is there an “absolute” method to determining spectrophotometer accuracy? i.e. is there a calibrated standard available with known LAB values?</x-tad-bigger>
<x-tad-bigger>And just how accurate should spectrophotometers be (+/- how much)?</x-tad-bigger>
<x-tad-bigger>How long is the white calibration tile good for?</x-tad-bigger>
<x-tad-bigger>
</x-tad-bigger>
Yes, there are standards for measuring spectrometer accuracy. The BCRA ceramic tiles are commonly used by the spectrometer manufacturers. These are a set of ceramic tiles of various colors and calibrated to NIST reference standards. There are also color standards from Labsphere and Avian Technologies which are made from special plastic materials, also calibrated to NIST references.
There are rare earth standards such as holmium oxide or erbium oxide that have precise peaks in the reflectance spectra which are used to check spectrometer wavelength accuracy.
These standards can be good for years, depending on their care and handling. They can also be recertified periodically by their manufacturers to update their calibrations.
Robin Myers
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden