Method and apparatus for detecting chemical compounds in soil

A spectrometer probe comprising:

• a shaft having a first end and a second end;
• a fiberoptic bundle located within the shaft, the fiberoptic bundle having a first end and a second end, wherein the shaft has no light source or spectroscope located within the shaft, wherein there are no air gaps in the shaft;
• an elastically deformable material, wherein the elastically deformable material is biasly connected to a prism support;
• and
• a prism, wherein the prism is located within the second end of the shaft.

A method for determining chemical compositions in soil, the method comprising the steps of:

• providing a spectrometer probe comprising:
• a portable carrier;
• an actuator;
• a shaft having a first end and a second end, wherein the shaft has no light source or spectroscope located within the shaft;
• a fiberoptic bundle located within the shaft, the fiberoptic bundle having a first end and a second end;
• a penetration cone operatively attached to the second end of the fiberoptic bundle;
• a prism;
• an elastically deformable material, wherein the elastically deformable material is biasly connected to a prism support;
• an index-matching elastomer, wherein the prism is completely encompassed by the index-matching elastomer, wherein the prism is flush with the prism support;
• and
• a backscatter baffle having a first end and a second end, wherein the second end of the backscatter baffle extends beyond the second end of the fiberoptic bundle
• using the actuator to insert the penetration cone into associated soil to a predetermined depth in the soil;
• passing light through the fiberoptic bundle;
• receiving light diffusively reflected back from the soil;
• and
• analyzing the diffusively reflected light with a spectrometer.

A spectrometer probe comprising:

• a shaft having a first end and a second end;
• a mirror, wherein the mirror is located within the second end of the shaft, wherein the mirror is angled at approximately a 45 degree angle in relation to the fiberoptic bundle;
• an index-matching elastomer;
• a fiberoptic bundle located within the shaft, the fiberoptic bundle having a first end and a second end, wherein the shaft has no light source or spectroscope located within the shaft, wherein there are no air gaps in the shaft;
• an outer sleeve having a first end and a second end, wherein the outer sleeve surrounds the shaft;
• an endcap attached to the first end of the outer sleeve;
• and
• a spacer tab, wherein the spacer tab is connected between a probe sample window and the end cap.