hoekmeter

A hoekmeter is an instrument used to measure angles. The term is Dutch, composed of "hoek" (angle) and "meter" (measurer), and can refer to a range of devices from simple protractors to precision electronic inclinometers and goniometers. Hoekmeters are used to determine the magnitude and sometimes direction of an angle in a plane or between surfaces.

Simple hoekmeters include the flat protractor, typically graduated in degrees, and bevel protractors used in metalworking. Mechanical clinometers and bubble inclinometers measure tilt relative to gravity, while optical and digital hoekmeters use lenses, encoders or accelerometers to provide readings. Goniometers are specialized hoekmeters for measuring joint or crystal angles in scientific contexts.

Accuracy and resolution vary with design: basic plastic protractors suffice for informal use, precision mechanical or digital instruments provide minute or sub-degree resolution suitable for engineering and surveying. Readings are commonly given in degrees; some devices also indicate radians or provide angular offsets and digital readouts.

Calibration and correct mounting are important for reliable measurements. Environmental factors such as vibration, temperature and magnetic interference can affect some electronic hoekmeters, while parallax can affect analog reading instruments.

Applications of hoekmeters span carpentry, machining, surveying, structural engineering, navigation, photography and medicine (for joint angle assessment). Selection of a specific type depends on required accuracy, range, portability and the nature of the surfaces or axes being measured.