B-H Curve: A characteristic curve showing the relation between magnetic induction (B) and magnetizing force (H) for a magnetic material. It shows the manner in which the permeability of a material varies with flux density.

Backlash: A form of mechanical hysterysis (lag) in which there is a lag between the application of a driving force and the response of the driven object.

Barometer: An instrument that measures atmospheric pressure.

Baud Rate: A unit of measure for data transmission speed. It represents the number of signal elements transmitted per second.

Best-Fit Straight Line: The equation of a straight line, calculated from a set of measurement results, which attempts to minimize the differences between the line and the measurement results. There is more than one statistical method used, each of which may place the straight line in a slightly different position with the respect to the measurement data.

Beta: The current amplification factor of a transistor when connected in a common-emitter configuration.

Bifilar Winding: A method of winding transformers in which the wires are placed side by side and wound together.

Bimetallic Element: Two strips of dissimilar metal bonded together so that a change in temperature will be reflected in the bending of the element, as a result of differential expansion.

A/D: Analog-to digital conversion.

Bleed Valve: A small valve to bleed off small amounts of water from container vessel or bath.

Blowdown: Removal of liquids or solids from a process/storage vessel or a line by the use of pressure.

British Thermal Unit (BTU): A unit of heat equal to the amount of heat required to raise one pound of water one degree Fahrenheit at one atmosphere pressure.

Buffer: A solution that maintains a set pH value regardless of added acids or bases.

Buoyancy: The power to float or rise in a fluid.

Buoyant Force: The upward force which any fluid exerts on a body placed in it.

Byte: Eight related bits of information processed as a unit. Eight bits equals one byte.