No doubt, this is the high time for any company to bring in their innovations in the market. People are ready to adapt the new technologies. If today one company launches a product with any new technology, several other companies start booming up with different option in that particular technology.
These days we are addicted of using various kinds of sensors in our life and when I say Sensors I don’t mean the Humans’ sense organs, rather I am talking about sensors. Sensors are also known as detectors which detect physical quantity and convert it into a signal. However, there are many types of proximity sensors which are invented for different applications and purposes.
What are Proximity Sensors?
Proximity sensor is device which detects objects nearby without being in the physical contact or the vicinity up to nominal range of that object. The maximum distance up to which the sensors can be relied to detect is called as ‘Nominal Range’. Nevertheless, you will often come across a term Sensing Object if you happen to go through some manual or talk to some proximity sensor supplier or trader.
The object being sensed is defined as Sensing Object.
Types of Proximity Sensors
Based on their uses and material detection capability and several other things, proximity sensors are of various types.
- Inductive proximity sensor: Inductive proximity switch is the device which produces output signals or electric signals when metal objects are falling into the sensing area i.e. nominal range from any direction. The metal objects include iron, aluminium, brass, copper etc with varied sensing distances.
- Capacitive proximity sensor: Along with the detection of metals, capacitive proximity sensors can detect resins, liquid and powders as well. The working of sensor can vary accordingly covering material, cable length, noise sensitivity etc. It also depends on the factors like temperature, sensing object, surrounding object etc.
- Magnetic proximity sensor: These kinds of sensors detect magnets and have no electrical noise effects. Its sensing can vary due to factors such as temperature, the sensing objects, surrounding objects and mounting distance between sensors. This type of proximity switch has the highest sensing range of up to 1200mm amongst all the three kinds.
Things you must keep in mind while buying this product
Since the proximity sensors allow the non-contact detection of objects of several kinds, they are employed in many industries including manufacturing, robotics, semiconductors and many more. All applications have certain specific needs; following points could be considered while selecting the correct sensor for your application.
- What is the sensing distance required?
Sensing distance is the distance between the tip of the sensor and the object to be sensed. In many applications, it is beneficial to place the sensor as far as possible.
- How much space is available for setting the sensor?
The shape and design of the proximity sensor which you are using varies with the space available. Sometimes a rectangular shaped sensor can do what a round shaped sensor cannot perform!
- Is a shielded or unshielded sensor needed?
The detection-range of these sensors depends on the mentioned types. These are also referred as embeddable or non-embeddable.
- Consider environmental placement concerns
Questions like Will the sensor be placed under water, in a high temperature environment, continually splashed with oil etc. will help you in determining the right type of sensor you want to use in a right manner.
- What is the sensor output connected to? (If using AC sensors, please skip the step)
The type of output you want must be determined, i.e. NPN, PNP or analog. Most products will accept any output. While connecting to a solid state relay, a PNP output is needed.
- Determine output connection type
Do you require an axial cable factory attached to the sensor or a quick-disconnect cable?
These cables have their own worth and are available in varied dimensions. Q/D cables are easy for maintenance and replacement.
Advantages of factory attached coaxial cable-
- Cost: The cable is integrated into the sensor and included in the price. Q/D cables are purchased separately.
- Environmental impact: The cable being sealed into the sensor, there is less chance of oil, water or dust getting penetrated into the sensor which could cause failure.