Patent ID: 8530844

Claim:
An apparatus for recording of wavelength absorption spectra in a substance, the apparatus comprising a probe for penetrating into the substance, the probe having light transmitting means and light receiving means for receiving light transmitted from the light transmitting means, the light transmitting means and the light receiving means defining an optical path of light between the light transmitting means and the light receiving means, the probe being shaped so that when the probe is inserted into the substance an interior portion of the substance at a depth corresponding to the insertion depth of the probe will be received in the optical path a means for determining the insertion depth of the probe in the substance, comprising a support for abutting an exterior portion of the substance and a stepping motor operating on the support, when the support abuts against the exterior portion of the surface, for extracting the probe from an inserted position, wherein the insertion depth is determined relative to the support during extraction of the probe; a light source for providing infrared light of multiple wavelengths to the light emitting means and a detecting unit for detecting wavelength spectra of light received by the light receiving means.