Hello
I am measuring the reflectance of some coatings using a Perkin Elmer spectro (lamda 950). In order to increase the precision I bought (from PE also) a Al reference mirror. It cames with a CD with a .sp and a .dx file (dx I dont know what is for).
First time I collected the R spectrum for the mirror (using standard 100% T and 0%T baselines) Indeed there are important discrepancies between the collected spetrum and one coming with the reference mirror (NIST +' .... certified). So I decided to measure the R for my films using this reference mirror.
The mathematics beyond is logic:
Corrected sample R = Collected sample Rx(Collected Mirror R/Standard mirror R)
HAving many samples to analyze and being lazy I prefer to use the automatic method suggested in the documentation coming woth mirror. However the explanation here are a little foggy:
" 1. Obtain a baseline spectrum using the Calibration Reference Mirror
2. Obtain a spectrum for the sample
3. Multiply them"
They ask me to do 2 measurements so I will have 2 files in the end. But in this case how I am inserting in this process the 3rd file from the CD - the standard spectra for mirror? How I can obtain a baseline spectrum from the reference mirror? If I am using the import option for the baseline and I insert here the "official standard file from the CD" then where I am using the mirror collected spectra? I am missing something? Can someone explain me how to collect a baseline from the mirror and then how to correlate with the standard spectra?
The standard spectra is only given for you to check your measurements of the reference mirror. They performed the measurement of a standard mirror at PE and provide you with that. You can check the quality of your reference mirror using that data. Besides this sanity check, you should not need the CD.
They way these usually work, is that you take a baseline measurement, which is automatically set as your zero point. Then, when measuring the reflection of a sample, the reference mirror is already incorporated. Then measure your samples without having to re-measure your reference (unless you start to get weird results). You should set the baseline before any set of measurements.
If you cannot set the baseline, then you would need to do the same thing, but manually calibrate your sample data after the fact. You should have one reference data file, and however many samples you measured. I am not sure why they want you to multiply, as you should subtract the sample measurements from the reference measurements. Unless there is something about this PE system that I am not familiar with.
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