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Empirical Verification Of 0.05mm Slit Width of DH4.0 v4 Spectrometer

by dhaffnersr | September 09, 2016 12:10 | 409 views | 0 comments | #13434 | 409 views | 0 comments | #13434 09 Sep 12:10

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Understanding Spectral Bandwidth and Resolution in the Regulated Laboratory

Upon closer scrutiny of my microscopic view of the 0.05mm slit width, I realized that the edges did not meet. This caused me great concern, although the measurements are correct as far as pixels go, on the title picture, (measuring from the razor's edge to the shadow of the lights edge from the bottom razor blade,) I re-examined my plots for the two laser scans I did recently and decided to isolate the green laser, as I had used it for calibrating my spectral bandwidth.

My laser that I use, is NOT some cheap off the shelf type, I have given its specifications several times in detail before, it is highly reliable and very stable monochromatic light source. There are two graphics below, the first one, explains how to determine spectral bandwidth and slit width, the second plot is mine, from the other day when I scanned both of my lasers, the 405nm uv laser pointer and the 532nm green laser.

spectral_bandwidth_chart_sept_9.png

532nm_lasers_sept_9_531_532_cutoff_slit_width_view.png

As is discussed in the data, I actually have a slit width of 0.5mm. I know what the problem is. I used construction paper to mount the two razor blades edge to edge, this is causing a slight bending effect, which can be seen in the title picture. The two edges are not meeting perfectly, so I am working on another one, where the mounting template will be more ridged and stable, and then I will re-verify that the edges do indeed meet and align.

Reference is below:

http://www.analiticaweb.com.br/newsletter/02/AN51721_UV.pdf - Understanding Spectral Bandwidth and Resolution in the Regulated Laboratory


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