Several companies recently have introduced inductive sensors with an extended range from 25 percent to 300 percent over standard products. (The industry standard sensing range is 2 mm for a flush mounted, unshielded sensor.) Of course, there really is no such thing as a free lunch, as some of the typical trade-offs for extended range sensors include operating temperature range, operating frequency, and noise immunity.
Turck's Uprox+ sensor detects iron, steel, stainless steel, copper, aluminum, and brass with no impact on the rated sensing distance. It uses two pairs of emitters and receiver coils printed on a circuit board instead of the wound coil in conventional ferrite core inductive sensors, resulting in sensing distances up to 250 percent higher. An integrated, predamping protection function allows flush-mounted sensors to be recessed by half a turn for enhanced mechanical protection. A slight reduction in sensing distance occurs for non-flush mounted sensors, but barrel-style sensors can be embedded in metal up to the outer edge of the thread and rectangular style sensors can be embedded on all four sides. For more information on Turck Uprox+ sensors, go to http://rbi.ims.ca/4393-513.
HYPERPROX EXTENDED RANGE SENSORS
Balluff's HyperProx extended range sensors have up to 300 percent greater range than standard-range sensors of the same size. However, the improvement is not necessarily linear or the same for all products. As an example, the standard M8 sensor has a 1.5 mm rating per the IEC standard and the 2× version, 3×, and 4× versions are 2, 3, and 4 mm, respectively. To achieve the performance boost, Balluff uses more windings and higher frequency wiring, including multistranded wiring to create higher field strength. The designs also employ tightened specs for components, such as the housing. For more information on Balluff HyperProx sensors, go to http://rbi.ims.ca/4393-514.
SERIES 2000 EXTENDED RANGE
Moduloc Series 2000 long-range inductive proximity sensors have sensing ranges from 20 mm (0.79 inches) to 200 mm (8 inches). The combination of large physical structures, coil materials, and construction provide the extended range. Non-flush units designed for mounting on steel have nominal ranges of 50, 75, and 130 mm. Flush units designed for embedded mounting on steel have nominal ranges of 20, 55, and 110 mm. Flat-pack, semi-flush units for mounting in surrounding steel framework have nominal ranges of 120, 140, and 200 mm and are available in lengths from 300 to 1,200 mm. All of these distances are for iron. Distances are reduced to 85 percent for CrNi, 54 percent for brass, 50 percent for aluminum, and 46 percent for copper. For more information on Moduloc Series 2000 sensors, go to http://rbi.ims.ca/4393-515.
X-SERIES EXTENDED RANGE
With a sensing range of 6 to 40 mm, Pepperl and Fuchs X-Series extended range inductive proximity sensors offer 50 to 100 percent greater range than standard inductive proximity sensors. For example, the unshielded, three-wire dc NEN40-30GM60-E2-V1 has a sensing range of 40 mm for an M30 non-flush mount. Operating at a switching frequency of 100 Hz, the unit has a nickel-plated brass housing and Crastin sensing face for use in harsh environments. A shielded X-Series M8 has a 2 mm range, and an unshielded version of 3 mm, compared to an industry standard of 1.5 mm. For more information on Pepperl and Fuchs X-Series sensors, go to http://rbi.ims.ca/4393-516.
EXTENDED RANGE SENSORS
Using a standard steel (cold-rolled steel St 37) target, the range of the shielded version for Carlo Gavazzi Inc.'s extended range sensors is 4 mm and the unshielded is 8 mm—both values are double that of standard sensors. Sensing ranges for M12 are 4 mm for the flush mount and 8 mm for the non-flush mount. Likewise, the M18 sensing range is 8 mm and 14 mm and the M30 is 15 mm and 22 mm. Operating frequency for the M12 shielded flush unit is 1,000 Hz versus 800 Hz for the unshielded, non-flush version. Similarly, the M18 is 500 and 400 Hz and the M30 is 400 and 200 Hz. For more information on Carlo Gavazzi extended range inductive sensors, go to http://rbi.ims.ca/4393-517.