A hard and wear-resistant material (such as a ceramic) used to wear, grind,
or cut away other material.

Accuracy

The degree of correctness with which the measuring system yields the "true
value" of a measured quantity, where the"true value" refers to an accepted
standard, such as a standard meter or volt. Typically described in terms
of a maximum percentage of deviation expected based on a full-scale
reading.

Affinity

A thermodynamic measurement of the strength of binding between molecules,
say between an antibody and antigen. Each antibody/antigen pair has an
association constant, Ka, expressed in L/mol.

Algorithm

A set of well-defined mathematical rules or operations for solving a
problem in a finite number of steps.

AM 1

The air mass 1 spectrum of a light source is equivalent to that of sunlight
at the earth's surface when the sun is at zenith.

Ampere (amp) [A]

Measure of electric current: 1A = 1 coulomb/second.

Amperometric Sensor

Amperometric sensors involve a heterogeneous electron transfer as
a result of an oxidation/reduction of an electro-active species at
a sensing electrode surface. A current is measured at a certain
imposed voltage of the sensing electrode with respect to the
reference electrode. Analytical information is obtained from the
current-concentration relationship at that given applied
potential.

Analyte

A chemical species targeted for qualitative or quantitative analysis.

Angstrom [Å]

Measure of length: 1 Å= 1x10^{-10} m.

Anisotropic

Exhibiting different values of a property in different crystallographic
directions.