Contact vs Non-Contact Sensor Technology
In the industry of manufacturing sensors, there is an ongoing trend of shifting towards widespread adoption of non-contact sensing technology. Various fields including medicine, automobile, industrial, and aeronautics are only a few of the markets that express a high demand for these sensors. The primary reason for choosing non-contact sensors is to minimise the cost and increase the resistance of a device to wear and tear. This article will further discuss and compare the benefits and challenges of using contact and non-contact sensors
Why the need for non-contact sensors?
Technology is dynamic and continues to advance, and sensors need to keep up with the need for higher accuracy, reliability, and durability. In recent years, manufacturers of contact sensor technology are being challenged by other manufacturers that prefer supplying non-contact sensors to end users. Despite the relatively lower cost of contact sensors, non-contact sensors tend to be more reliable and also last longer; hence, the cost of acquisition is justified and maximised.
Industries are also evolving in such a way that more emphasis is placed on ensuring that machine assemblies are using highly accurate sensors; therefore, causing a shift towards preferring non-contact sensors over conventional contact sensor technology.
Examples of non-contact sensors
Magnetic devices, especially sensors, produce a magnetic field which causes the sensor to wear out quickly. This is not a problem when using a Hall-effect magnetic sensor because it is capable of detecting the presence of a magnetic field, but without getting in contact with the source; hence, eliminating friction. Hall-effect sensors are quite popular with manufacturers of original equipment parts because these sensors do not get damaged easily which means that the sensor lasts longer.
Another example of a non-contact sensor is an LVDT. This type of linear sensor is highly suitable for robust industrial applications including underwater installations. LVDTs have improved significantly over the years due to sophisticated manufacturing technology and the use of new materials such as nickel alloy. LVDTs today also have improved stroke-to-length ratios making them suitable for hydraulic and pneumatic machines.
Magneto strictive linear position sensors also make use of non-contact technology which makes these an ideal solution for many automotive applications.
Contact sensor technology
The most common example of a contact sensor is a potentiometer. It consists of a rod or shaft which is mechanically connected to the object being measured. As the object moves, the shaft also moves along a resistive track. The resistance produced will fluctuate according to the shaft’s position on the track which corresponds to the object’s displacement
Potentiometers are economical and easy to install, but the contact nature of this device makes it unsuitable for demanding applications. Since non-contact sensors are more reliable and are now comparably priced, many industries are shifting towards the use of non-contact sensors rather than conventional potentiometers. Nevertheless, there is still a steady demand for these simple devices such as in consumer electronics and applications that are not subject to harsh conditions.
In conclusion, both contact and non-contact sensor technologies remain relevant across various industries. The decision to choose non-contact sensors is due to the desire to achieve higher accuracy, reliability, and increased assembly life cycle.