TIPS & TRICKS: SENSORS
TAKING ‘STOCK’ OF INVENTORY Sensors are integral elements of the automation era. Recent advancements in sensor technology have improved their accuracy and reliability, while reducing the cost. However, sensors are prone to failure due to various reasons, thereby resulting in the need for stocking huge amount of replacement sensors. Hence, companies are now aiming at reducing the sensor stock. One just needs to master the tricks provided herewith. sensors required to do the job. A smaller sensor also offers increased mounting flexibility, as it can fit in places where larger sensors cannot. If the targets are non-ferrous, the use of Factor 1 sensors is recommended. These sensors achieve longer sensing ranges than traditional sensors, because these n a perfect automation world, sensors never need to be replaced. They never die or suffer the effects of their environment. But in the real world, this is not the case. Such things happen often and increase the amount of sensors needed at any given point in time. Stocking replacement sensors for applications can pose a problem, as a result of the time it takes to find the right replacement; the confusion that goes along with finding the appropriate shape with the correct sensing range; the space it takes to stock all this inventory and, of course, the huge amount of capital invested. This brings us to the question of how to reduce the need for spare stock.
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RESOLVING ISSUES There are several ways to bring down sensor stock levels, but one of the easiest and most efficient ways is standardisation. Standardising on styles, sizes and brands is the first step in reducing the sensor stock. Using smaller sensors with extended range is another great way to reduce it. Sensors that are specified for extended range can replace several (often bulkier) other sensors, thereby reducing the number and type of
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Electromagnetic interference (EMI)/ radio frequency interference (RFI) can interact with sensing elements, causing the sensor to lock on or ‘chatter’. Noise emitting devices can range from two-way radios to motors and drives, so the possibility that a sensor will be exposed to EMI/RFI is relatively high. This will only increase with the increasing use of wireless communication. Several sensors have been
QUICK TAKE Factor 1 sensors achieve longer sensing ranges than traditional sensors, because these can detect non-ferrous metals at the same rated distance as steel. Many Factor 1 sensors also lack a ferrite core, allowing them to be incorporated into unique and non-traditional housings that may easily replace other sensors. can detect non-ferrous metals at the same rated distance as steel. Many Factor 1 sensors also lack a ferrite core, allowing them to be incorporated into unique and non-traditional housings that may easily replace other sensors, therefore reducing the amount of sensors should be kept in hand.
BEST PRACTICES It would be a good practice to mount a sensor, and then there would be little likelihood that it will be hit by the target. A target hitting a sensor is one of the major causes of sensor failure. If the application or location requires a sensor to be very close to the target, one must try to use a sensor that can be recessed in its mounting apparatus to promote a higher degree of protection from the target. It is vital to choose a sensor that has been designed for recessed mounting, as a conventional proximity sensor will lock on, if recessed in metal.
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designed for noise immunity, including Factor 1 sensors. If Factor 1 sensors are used, stocking noise-immune sensors can be ruled out. Another way to reduce overall stock levels is to standardise the sensor’s connector sizes, along with corresponding cables/cordsets. Choosing a quick disconnect sensor/cable combination will also lessen installation time. This might sound basic, but make sure the sensor supplier has local support or is willing to visit a given location – wherever it is. Sometimes sensors need to be applied in tricky situations and remote support from the supplier just would not cut it. Even the best sensors sometimes need onsite troubleshooting. When issues arise, it is in the best interest of one and all to ensure reliable support wherever it is needed and fast. Courtesy: TURCK Inc.