MR326 Encoder

MR328 Encoder
October 21, 2015
MR325 Encoder
October 22, 2015

MR326 Encoder


ZapFREE® Size 90mm Fiber Optic Incremental Encoder

The MR326 ZapFREE® Heavy Duty 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.




Measurement Parameters


100, 128, 256 and 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


Body: Anodized Aluminum; Shaft and Bearings: Stainless Steel

Moment of Inertia

2.5095E-6 kg*mm2

Starting Torque

1.012E-3 N*m

Max Shaft Loads

Radial = 140 N (31 lbf), Axial = 70 N (15 lbf)

System MTBF

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

8.96E+05 hours (102.3 years)

Optical Interface


Duplex LC on pigtail or ODVA IP-LC receptacle

Fiber Type

Duplex MM 62.5/125µm, Graded Index, 0.275NA

Link Length

Max distance is the lesser of 2500m (8300 ft) OR 2-way optical loss of 12.5dB at 850nm

Physical Attributes

Housing Dimension

Ø90 mm x 82.5 mm

Unit Weight

615 g (21.5 oz)

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


EPL Mb/Gb/Gc/Db/Dc


EPL Mb/Gb/Gc/Db/Dc



Environmental Attributes


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

Extended Option: -60°C to +150°C / 0% to 95% RH (non-condensing)

Ingress Protection

IP66 (strong water jets and temporary immersion)

Specifications subject to change without notice


  • 100% passive, all-optical sensing design
  • Sensor can be installed in all manner of hazardouslocations 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 that “zaps” conventional electronics-based encoders
  • Outdistances copper, link lengths to 2500m
  • Standard model operates -40°C to +80°C
  • Extended Temperature option covers -60°C to +150°C
  • Special versions can be engineered for radiation and thermal-vac environments


Call 805.389.6600

Ordering Information