Quick Optics Question on Gratings (Small calculation)

AI Thread Summary
A user inquires about calculating the distance between grooves in a grating with 3,000 slits per mm, concluding that the distance is 3.33x10^-4 mm. They seek clarification on using this value in the formula n λ = d sin(θ) for determining wavelength, confirming that the wavelength should match the units of "d." The user has conducted an experiment with a sodium lamp and spectrometer but struggles to find reliable wavelength data for comparison. A suggestion is made to convert measurements to more convenient units, such as nanometers. The discussion highlights the importance of unit consistency in optical calculations.
_Mayday_
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Hey,

Well, just a quick question, if a grating had 3,000 slits per mm, what would the distance between groves be? Is it 1mm/3,000 which would give me the grove distance?
 
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So 1/3000 = 3.33x10^-4 is the distance between gooves?
 
CrawfordK said:
Is it 1mm/3,000 which would give me the grove distance?
Sounds right to me.

CrawfordK said:
So 1/3000 = 3.33x10^-4 is the distance between gooves?
In mm.
 
^ When using using the formula n \lambda = d \sin(\theta) trying to find the wavelength would I use it in mm?

I've basically conducted an experiment, using a sodium lamp and spectrometer, and want to see how accurate it is by comparing my results with an online result, but am having trouble finding a source that tells me the wavelengths, that I can compare to with my results.
 
_Mayday_ said:
^ When using using the formula n \lambda = d \sin(\theta) trying to find the wavelength would I use it in mm?
When using that formula, the wavelength will have whatever units "d" has. You can always convert it to more convenient units, such as nm.

This might help: http://hyperphysics.phy-astr.gsu.edu/Hbase/quantum/sodium.html#c2"
 
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I swear I saw a blue line as well though? For the orange line i got 5.7x10^-5 mm, i don't know hwo accurate that is.
 
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