OTG-M420 Fiber Optic Temperature Sensor

High Accuracy GaAs-Based Fiber Optic Temperature Sensor for Medical and Animal Physiological Temperature Measurement.

OpSens’ OTG-M420 fiber optic temperature sensor offers the highest performances in the industry. The OTG-M420 sensor uses the well proven technique based on the temperature-dependent bandgap of GaAs crystal as the temperature transduction mechanism. Its small sensing GaAs crystal located at the tip of the optical fiber makes it convenient for tip measurement applications.

Combined with OpSens’ GaAs signal conditioning technology and with the inherent advantages of fiber optic, the OTG-M420 delivers unprecedented repeatability and reliability in the most adverse conditions such as high level of EM, RF, MR and microwave field environments.

The OTG-M420 has a protective Polyimide tube of 0.42mmOD over its sensing crystal making it robust and suitable for applications that requires some robustness.


  • ± 0,3 °C accuracy
  • Small and robust design
  • Outstanding repeatability
  • MRI (<1.5T)/EMI/RFI and microwave immune
  • Intrinsically safe
  • OEM-type and custom version


  • Surface and core temperature monitoring in MRI environments
  • RF, ultrasound and electro surgery environments
  • Temperature monitoring for preclinical and research applications

Ordering Information

Ref / Catalog Number Order Number (GTIN) Description
Temperature operating range20 °C to +45 °C (higher temperature ranges available upon request)
Resolution0.01 °C
Accuracy± 0.3 °C (Total accuracy over the full range from 20 to 45 °C including both signal conditioner and sensor errors)
± 0.8 °C and better (Total accuracy for higher temperature range including both signal conditioner and sensor errors)
Response time220 ms or better
Operating humidity range0-100 %
MRI/EMI/RFI susceptibilityComplete immunity (MR field <1.5T)
CalibrationNIST traceable
Cable length1.5 meters standard (other lengths available)
Optical connectorST standard
Sensor diameter0.420 mm O.D.
Cable sheathingPVC tight buffer (≤ 85 °C) or Teflon™ (≥ 85 °C)
Signal conditioner compatibilityAll Opsens GaAs signal conditioners

All specifications are subject to change without prior notifications

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