| 摘要 |
<p>Light having a predetermined wavelength band as issued from a light-emitting diode is launched into a gas absorption cell which is filled with a gas having a plurality of absorption spectra. The light launched into the cell has a plurality of wavelengths absorbed by the gas. The absorption wavelengths are known and their values are preset in a memory in an optical spectrum analyzing section 58. The light passing through the cell is launched into the optical spectrum analyzing section 58, where it receives arithmetic operations to produce an optical spectrum. The optical spectrum analyzing section 58 has a CPU which compares a plurality of wavelengths having dominant absorption in the obtained optical spectrum with the preset reference wavelengths to compute the errors in wavelength measurement. The calibration value is determined on the basis of the average of these errors and the optical spectrum analyzer is accordingly calibrated in wavelength. <IMAGE></p> |
