<<PREVIOUS - HOME - CONTENTS - NEXT>>
SPECTROSCOPY INDEX - New

Spectra L200 Spectrograph
Higher Orders Overlap Tests with F4T5D Light

These specturms show the L200 higher orders overlap (2, 3 and 4) when using a 600l/mm grating.

The spectrums are of a hand held five inch fluorescent (Satellite F4T5D) light taken with an unpainted Spectra L200. The fluorescent light uses excited mercury atoms and therefore the spectrum has strong mercury emission lines

The bright and colorful mercury emission lines make it easy to identify the wavelengths.

See the Spectrum of Mercury Gas Discharge for a colorful spectrum diagram that helps to identify the mercury emission lines.

The camera is a very old Nikon Coolpix 990 Digital Camera afocal coupling to an eyepiece (STWA18 Wide Angle 18mm Eyepiece/Adapter ) with built in adapter threads to the camera.

Short wavelengths are on the left side of the spectrum and long wavelengths are on the right side of the spectrum. The spectrum images are one quarter size and all spectrum are cropped the same way from the original images. The spots in the spectrum images are hot pixels.

Grating order one ends at 8,064 and at the same time grating order 2 starts 4,032 for the L200 600l/mm grating at 14 degrees. Higher grating orders two and above start to overlap as is shown in the below chart and table. Excel table and graph (L200GratingOrderChartV1.0.xlsx, 50KB)

Grating Orders Overlap Graph


Summary
H-alpha ~6,563 for order two is at ~23 degrees. This angle will overlap with order three at ~ 4,300 . A CCD camera short wavelength sensitivity starts just below ~ 4,000 and continues into the infrared spectrum. Therefore, using the L200 at H-alpha (order two) will also collect order three spectrum data at ~ 4,300 .

The next H-alpha at order two L200 test is to use a red filter to block the order three violet spectrum from being recorded by the CCD camera.


Second Order
4358.328 - Violet Emission Line

Satellite F4T5D light Specturm


Second Order
4358.328 - Violet Emission Line

Satellite F4T5D light Specturm


Second Order
5460.735 - Green Emission Line

Satellite F4T5D light Specturm


Second Order
5460.735 - Green
5769.598 and 5790.663 - Yellow, Emission Lines

Satellite F4T5D light Specturm


Second Order
5769.598 and 5790.663 - Yellow, Emission Lines

Satellite F4T5D light Specturm


Second Order
5790.663 - Yellow,
6149.475 - red Emission Lines

Third Order Overlap
4046.563 - Violet Emission Line

Satellite F4T5D light Specturm


Third Order
4358.328 - Violet Emission Line

Satellite F4T5D light Specturm


Third Order
5460.735 - Green
Emission Line

Fourth Order Overlap
4046.563 - Violet Emission Line

Satellite F4T5D light Specturm


Third Order
5769.598 and 5790.663 - Yellow, Emission Lines

Fourth Order Overlap
4358.328 - Violet Emission Line

Satellite F4T5D light Specturm
Grating Orders Overlap Table


Spectra L200 Spectrograph