Calculating NIR Path Length for Gas Absorption Analysis

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Discussion Overview

The discussion revolves around determining the minimal and maximum path length for gas absorption analysis, specifically in the context of Beer-Lambert's Law. Participants explore the parameters that influence these calculations, including gas concentration, beam diameter, pressure, temperature, and transmission.

Discussion Character

  • Exploratory, Homework-related

Main Points Raised

  • One participant expresses uncertainty about the correct formulas and order of operations needed to apply Beer-Lambert's Law for gas absorption.
  • The same participant lists several parameters they believe are important for calculating acceptable path lengths, including gas type, concentration, beam diameter, pressure, temperature, and transmission.
  • Multiple posts indicate a desire for assistance and clarification on the topic, suggesting a lack of confidence in the initial question posed.
  • There is a sentiment of frustration expressed regarding the difficulty in receiving help on the forum.

Areas of Agreement / Disagreement

Participants generally express a lack of clarity and seek guidance, but there is no consensus on the specific methods or formulas to use for the calculations.

Contextual Notes

The discussion reflects a range of assumptions about the necessary parameters for gas absorption analysis, but it does not resolve the mathematical steps or the definitions of terms used.

Who May Find This Useful

This discussion may be of interest to individuals involved in spectroscopy, gas analysis, or those seeking to understand the application of Beer-Lambert's Law in practical scenarios.

mobilecal
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Hi everyone,

Yes I am a newbie here so forgive me if I don't ask the question correctly. I am trying to understand how to determine the minimal and maximum path length based on gas absorption.

I know this is based on Beer Lamberts Law but I am not sure which formulas to use and the order to use them. I appologize but I am not degreed in physics, but I have been a hobbist in spectroscopy and gas analysis for about 2 years.

In my thoughts I figured tat a minimal the following parameters must be considered.
1. Path Length
2. Gas (O2-760nms, 1% by volume)(range is .5% to 20%)
3. Beam Diameter
4. Pressure
5.Temperature
6. Tansmission

So if I did not ask correctly, I know the gas I am trying to measure, but not sure how to calculate what path length would be acceptable based on the sensitivity and range.

I am willing to do the work, just looking for some guidance here. Thank you in advance.
 
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Could someone give me a hand here or tell me maybe I should ask this question on another Physics Forum Page? I hope I posted on the proper page. Thanks in advance.
 
Any help or direction would be appreciated. Thanks in advance.
 
sure is hard to get help on this forum. Guess its too complicated for some.
 

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