MR322 Encoder

MR325 Encoder
October 22, 2015

MR322 Encoder


ZapFREE® Size 58mm Fiber Optic Incremental Encoder

The MR322 series ZapFree® Fiber Optic Incremental Sensor is an entirely passive, intrinsically safe, fiber optic incremental rotary encoder – ideal for a wide range of harsh and hazardous environmental applications. The passive, all-optical Sensor connects to the remote Controller via a standard duplex 62.5/125 multimode optical fiber link.

The remote MR320 Controller Module transmits and converts optical signals to/from the Sensor. The Controller’s multiple built-in interfaces insure compatibility with industry standard motor drives, PLCs, quadrature counters and motion control systems.

ZapFree    NEC


Measurement Parameters
Resolution 100, 128, 256, 360ppr (Consult Micronor for special requirements)
Max Speed

8,000 RPM continuous (using MR320 quadrature outputs only)

5,000 RPM (using MR320 Quadrature and some Auxiliary Functions)

Note: There is a tradeoff between operating speed and use of MR320 auxiliary functions (analog outputs, divider, multiplier, etc.). Contact Micronor to discuss your requirements.

Mechanical Parameters
Moment of Inertia 1.0585E-6 kg*mm2
Starting Torque 1.28E-5 N*m
Max Shaft Loads Radial = 80 N (18 lbf), Axial = 40 N (9 lbf)
System MTBF

L10 Bearing life calculated at 50% of max radial and axial load at 2500 RPM:

1.78E+05 hours (20.3 years)

Optical Interface
Optical Interface LC Duplex, 62.5/125μm Graded Index Fiber, 0.275NA, Type OM1
Link Length Up to 2500 meters with MR320 Controller
Explosive Atmospheres Inherently Safe, Simple Mechanical Device
EX Classification

Inherently safe, simple mechanical device when used with MR320 Controller

IECEx Test Report (ExTR) GB/CML/ExTR 16.0039/00

IEC Ex EPL Mb/Gb/Gc/Db/Dc
NEC Exempt
Environmental Attributes

Standard: -40°C to +80°C, 0%-95% RH (non-condensing)

Extended: -60°C to +150°C, 0%-95% RH (non-condensing), Not available with D00 Option

Ingress Protection IP64 (splash proof)
Physical Attributes
Housing Dimension Ø 58mm x 58mm
Unit Weight 210 g (7.25 oz)
Materials Body: Anodized Aluminum; Shaft and Bearings: Stainless Steel

Specifications subject to change without notice


  • 100% passive sensing design – no electronics whatsoever
  • Sensor can be installed in all manner of hazardous locations and potentially explosive atmospheres – mines, gas and dust
  • Immune to EMI and RFI for safe use in and around medical equipment and “noisy” industrial environments
  • Immune to lightning and high voltages
  • Outdistances copper, link lengths to 2500 meters
  • Standard model operates over -40°C to +80 °C
  • Extended Temperature option covers -60°C to +150 °C
  • Special versions can be engineered for radiation and vacuum environments


Call 805.389.6600

Ordering Information