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The following links provide additional information on capacitive sensors and some of the more popular application set ups.

Want to know more about inductive, magnetic or photoelectric sensors? Still not quite certain... contact us.

 
Choosing the right sensor can be a daunting task. Should it be inductive, capacitive, magnetic, photoelectric or ultrasonic?
Inductive units detect metal. Sensing distances that are cited in the catalogue pages were derived from using a square piece of 1mm thick ferrous steel. De-rating factors should be used for other metal objects as follows:
Stainless Steel 0.9 x sensing distance
Brass 0.5 x sensing distance
Aluminium 0.4 x sensing distance
Copper 0.4 x sensing distance
Capacitive sensors will detect just about anything or can be adjusted to ignore non-ferrous material. This is especially convenient if the container is non-metallic and we want to detect the substance within. We butt the unit up against the outer wall and desensitize it via the built in potentiometer until the wall is no longer detected. Then, when material is present at the height of the sensor, it will activate the output. No hole to drill and the sensor is never in direct contact with the product.
De-rating factors are also used if non-ferrous metal is being detected as follows:
Water 1.0 x sensing distance
Plastic 0.5 x sensing distance
Glass 0.5 x sensing distance
Wood 0.4 x sensing distance
Photoelectrics can also detect just about anything and are available in three basic configurations depending on the distance from the product being detected. Direct reflection types transmit a beam that is reflected back to it from the object detected. For greater distances, a reflector is placed opposite the transmitter and the output is triggered when the object breaks the continuity of the beam. Finally, for distances of 20 meters, a transmitter is mounted opposite a receiver and again the output is triggered when the object breaks the continuity of the beam. Magnetic sensors detect only magnets; but, have several advantages. Detection distance is one. These are offered with reed relays up to 3 amps, thus eliminating the need for interposing relays in many applications. For faster response, we also offer units with PNP or NPN outputs. Great for over/under speed monitoring. Then some special units that will only respond to the South Pole of a magnet, others the North Pole and still others latch upon detecting the South Pole and unlatch in the presence of the North Pole. Read all about these amazing sensors by clicking on HowThey Work. Ultrasonics are mostly used when an analog output is required. They generate high frequency sound waves and evaluate the echo which is received back by the sensor. The time interval between sending the signal and receiving the echo determines the distance to an object. Very accurate, these can be used in dusty, foggy environments under all types of lighting (or lack thereof) conditions. Keep in mind that all ultrasonics have a ''dead zone'' or blind spot. If the unit is rated 20 to 200 mm, it will not detect items closer to it that 20 mm.