MR332 Encoder

MR332 Encoder

ZapFREE® Fiber Optic Absolute Position Sensor

The MR330 Series ZapFREE® Fiber Optic Absolute Position Sensor measures absolute angular position from 0° to 360° with 0.025° resolution.

This innovative sensor system outdistances conventional absolute encoders and resolvers – transmitting interference-free up to 300 meters! The system consists of a passive optical sensor (MR332) and active controller (MR330) linked via industry standard 62.5/125μm multimode fiber. Interconnect options include commercial Duplex LC or industrial grade ODVA IP-LC Duplex.


Measurement Parameters
Measurement Range 0° to 360° (continuous)
Resolution 13 bits (8192), 14 bits (13950)
Maximum RPM Maximum 2,500 rpm for position reading; Mechanical limit is 6,500 rpm
Mechanical Performance
Moment of Inertia 2.88E-06 kg*m2 (4.08E-04 oz*in*s2)
Starting Torque < 0.02 N-m with Shaft Seal
Max Shaft Loads Axial 40 N (9 lbf), Radial 80 N (18 lbf)
System MTBF (ISO Method)

L10 bearing life at 100% of max radial/axial load at 2500 rpm: 4.650E+04 hours

L10 bearing life at 10% of max radial/axial load at 2500 rpm: 1.988E+06 hours

Explosive Atmospheres Inherently Safe, Simple Mechanical Device
EX Classification Inherently safe, simple mechanical device when used with MR330 Controller IECEx Test Report (IECExTR) GB/CML/ExTR 16.0070/00
IEC Ex EPL Mb/Gb/Gc/Db/Dc
NEC Exempt
Environmental Performance
Temperature/Humidity Operating: -40° C to +80° C, Storage: -40° C to +80° C; 0%-95% RH (non-condensing)
Ingress Protection

Shaft Seal Option Y With D00 Industrial LC Connector Option = IP66/IP67

Shaft Seal Option Y With CXX Duplex LC Pigtail Option = IP65

Shaft Seal Option N = IP40

Physical Attributes
Housing Dimension Ø 58mm x 80mm L (industry standard 58mm servo mount housing)
Unit Weight 500g (18 oz)
Materials Body: Anodized Aluminum; Shaft and Bearings: Stainless Steel

Specifications subject to change without notice


  • 100% passive sensing design – no electronics whatsoever
  • Absolute 14-bit single-turn resolution
  • Sensor can be installed in all manner of hazardous location and explosive atmosphere – 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 300 meters
  • Standard model operates over -40°C to +80 °C
  • Special versions can be engineered for radiation and thermal-vac environments