4mm Is The New 2mm

When I began working in the industrial sensor industry back in the mid-’90s, the standard sensing range for a size M12 flush-mount inductive proximity sensor was 2.0 mm.  Advances in sensor technology later brought about so-called “Extended Range” proxes, with M12 flush-mount proxes rated at 4.0 mm nominal sensing distance.  Another popular term for these extended range proxes is “2X”, as in “Two Times” the standard sensing range.

Today, competition and time has brought down the prices of most 2X sensors close to or equal to the prices for standard “1X” sensors.  As a result, there’s a large and growing industry trend to just go ahead and standardize on 2X sensors.  And why not?  If the cost is essentially the same, dollar for dollar a sensor with more range is a more versatile sensor.  The availability of longer range in smaller housings is driving migration from M18 bodies to M12 bodies, and from M12 housings to M08 housings.  This saves money and helps reduce the size and weight of modern machinery.

Longer range also makes for more stable and reliable applications.  A longer range sensor has a larger detection zone, and is more tolerant of target position variance within that larger zone.  This can prevent troublesome applications where a standard 1X sensor must be periodically adjusted to compensate for target location drift over time.

A final benefit of longer range sensors is the most obvious: the sensor can operate at a longer distance away from the target.  The wider separation distance forms a bigger safety cushion for the prox and helps prevent damaging impacts.  The more standoff distance there is between the sensor and the target, the less likely the prox will be damaged by unintended impact.

The rise in use and adoption of 2X sensors is reaching a point that it might be time to ask, “Have 2X sensors become the de facto new ‘standard'”?  Increasingly, many specifiers and users would answer with a resounding “Yes”!

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