Method and device for realizing optimal modulation factor of multi-gas spectral line detection
A technology of modulation coefficient and realization method, applied in the measurement of gas concentration, pressure or flow velocity, and temperature field, can solve the problems of inability to take into account spectral line parameters, multi-gas spectral line sensitivity and low accuracy, and achieve the effect of improving accuracy
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0055] Example 1: (measure the concentration of three gases near 1580nm)
[0056] In the wavelength range of 1580.5nm ~ 1581.0nm, CO can be measured 2 , CO, C 2 h 2 For the three gases, the parameters of the absorption lines can be obtained from the HITRAN database. Using DFB laser, the concentration of these three gases can be covered and measured in one wavelength scan period. However, the three spectral lines to be measured have different spectral line parameters, as shown in Table 1.
[0057] Table 1.CO 2 , CO, C 2 h 2 The parameters of the absorption line around 1580nm (T=296K, P=1atm, x CO2 =x CO =x C2H2 =1%, 97% air)
[0058] serial number
gas molecule
Spectral line wavelength / nm
Absorption line strength / cm / molecule
Spectral line width / nm
[0059] 1.
CO 2
1580.993
1.13E-23
0.0359
2.
CO
1580.828
1.57E-23
0.0319
3.
C 2 h 2
1581.129
9.08E-25
0.0385
...
Embodiment 2
[0070] Example 2: (1.395um temperature measurement, open optical path)
[0071] Measure temperature by measuring multiple absorption lines of water molecules, H around 1395.6nm 2 The absorption spectrum parameters of O can be obtained from the HITRAN database, as shown in Table 2. Using a DFB laser, one wavelength scan cycle can cover two H2O absorption lines. However, since the two spectral lines to be measured have different spectral line widths, they are:
[0072] Table 2.H 2 The parameters of the absorption line of O around 1395.6nm (T=296K, P=1atm, x H2O =10%, 90% air)
[0073] serial number
Spectral line wavelength / nm
wave number / cm -1
Absorption line strength / cm / molecule
Spectral line width / nm
1.
1395.693
7164.90
1.47E-22
0.0202
2.
1395.514
7165.82
5.93E-21
0.0505
[0074] The use of DFB lasers can cover these two spectral lines within a wavelength scanning period. In the current existi...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More