Micronor's fiber optic rotary encoder patented for harsh environments

Micronor has secured US patent 7,196,320 for its ZapFREE fiber optic rotary encoder system.

Offshore staff

NEWBURY PARK, California-- Micronor has secured US patent 7,196,320 for its ZapFREE fiber optic rotary encoder system. The patent recognizes Micronor's wavelength division multiplexing approach, which produces a passive encoder using no electronics within the sensor.

The product is deployable in harsh environments, hazardous locations, electrical, electromagnetic, and in radiation fields. The MR3XX fiber optic sensors meet ATEX requirements as a simple apparatus and are certified for use in any type of combustible atmosphere group or hazardous location.

The technology was commercially introduced in 2004 as the MR3XX ZapFREE fiber optic encoder series – the world's first commercialized, totally passive, single fiber, rotary sensor system. Mainstream industrial applications now range from aerial cable cars to steel mills and oil rigs.

The system uses a multi-wavelength light source and one optical fiber leading to an encoder housing, which has a shutter wheel, a light filter assembly, and reflective mirror. The rotational movement of the shutter produces a sequential series of light pulses sequenced proportional to the movement of the shutter. The light filter assembly uses a minimum of two different filters each of which passes or rejects light within a certain space and wavelength range.

Micronor's commercial product line has expanded to include three sensor models (MR312/MR314/MR316) powered by a common optoelectronics/remote encoder interface (REI) module (MR310). The sensors are available in resolutions from 100 to 1024 ppr (pulses per revolution) as well as industry-standard shaft or hollow shaft configurations - intermountable with conventional rotary encoders.

The MR310 module offers conventional A/B quadrature outputs (in both line driver and pull-up signal formats). The module also provides a rich set of auxiliary functions (multiplier, divider, and position counter), fully configurable analog outputs (both 4-20mA and ±10V) and RS422/RS485 (optional RS232) serial interface. The interfaces ensure intermateability with all major motor drive, motion control, and PLC systems.


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