Composite materials and calibration assemblies using the same

An apparatus for calibrating a formation evaluation tool comprising:

• a first body comprising a first material and having a first geometry;
• a second body comprising a second material formed to receive the first body;
• and
• a third body comprising a third material formed to receive the second body;
• wherein the first and second materials and the first geometry are selected so that a calibration property of the apparatus substantially matches a corresponding calibration property of a fourth material that is different from the first and second materials.

A method, comprising:

• transmitting a signal from a downhole tool;
• receiving the signal at a sensor of the downhole tool through a composite material formed from two or more other materials through at least one of machining or assembly, wherein the composite material is configured such that the sensor is configured to measure a property of the composite material that is substantially similar to that measured for a calibration material, wherein the composite material comprises a plurality of pins comprising a first material inserted into a body comprising a second material different from the first material, the plurality of pins arranged in a rectangular array;
• and
• adjusting an output of the sensor based on the measured property of the composite material.