Ultrasonic Level Switch Principle
Yet another style of electronic level switch uses ultrasonic sound waves to detect the presence of process material (either solid or liquid) at one point: Sound. Sound waves pass back…
Paddle Wheel Level Switch Principle
A more primitive variation on the theme of a “tuning fork” level switch is the rotating paddle switch, used to detect the level of powder or granular solid material. This…
Tuning Fork Level Switch Principle
Tuning Fork Level Switch uses a metal tuning fork structure to detect the presence of a liquid or solid (powder or granules) in a vessel: Tuning Fork Level Switch An…
Float level switch Principle
Some level switches use a float to sense the level of a liquid surface, actuating an electrical switch by the motion of the float. The electrical schematic symbol for a…
Capacitive Level Switch Principle
Another electronic liquid level switch technology is capacitive: Sensing level by changes in electrical capacitance between the switch and the liquid. The following photograph shows a couple of capacitive switches…
Basics of Pressure switches
A pressure switch is one detecting the presence of fluid pressure. Pressure switches often use diaphragms or bellows as the pressure-sensing element, the motion of which actuates one or more…
Basics of Limit switches
A limit switch detects the physical motion of an object by direct contact with that object. An example of a limit switch is the switch detecting the open position of…
Conductive Level Switch Principle
Perhaps the simplest (and oldest) form of electrical level detection is where a pair of metal electrodes contacts the process material to form a complete electrical circuit, actuating a relay.…
OTDR Testing
An Optical Time-Domain Reflectometer or OTDR is a sophisticated test instrument used to probe the characteristics of long optical fibers. They work by injecting a very brief pulse of light…
Fiber Optic Cable Testing
Fiber optic cable testing is done to ensure all installed cable lengths and connectors are functioning properly.
