Abstract: Positioning apparatus for presenting a sample for electromagnetic analysis comprises a flexible, resilient, generally cylindrical, open-ended inner sleeve member having a lengthwise through slit, such that the effective diameter thereof is adjustable over a predetermined range in response to radially inward compression thereof. An elongate constricting assembly surroundingly engages and selectively applies radially inward compression to the inner sleeve member. The constricting assembly comprises a pair of generally rigid, cylindrical axially spaced gripping members and a plurality of resilient, helical members coupled intermediate the gripping members. The helical members are responsive to relative rotation of the gripping members in a first direction for applying radially inward compression to the inner sleeve member, and responsive to relative rotation of the gripping members in an opposite direction for releasing radially inward compression on the inner sleeve member.

Abstract: A soil test apparatus for field use comprises structure adapting the apparatus for transport over a field for testing the soil thereof; an infrared radiation generator for producing infrared radiation at a plurality of predetermined wavelengths, an elongate light carrying member coupled to the infrared radiation generator and extending therefrom for directing infrared radiation onto the soil; and a light detector for detecting infrared radiation reflected from the soil and for producing corresponding electrical signals.