Gallium arsenide based fiber optic temperature signal conditioners

FOTEMP1-OEM, Fiber optic thermometer

The fiber optic thermometer FOTEMP1-OEM is ideal for the use in microwave, high frequency and high voltage environments.

FOTEMP1-OEM was designed to be integrated into your own system. Through its compact design a retrofit into existing model series is possible. It is ideal for fiber optical temperature measurement in high electromagnetic interfered environment, in microwave fields and other environments, where measurement with electric temperature sensors is not possible.

The standard analog output and RS-232 communication port allow for real-time data acquisition. The FOTEMP1-OEM, Single-channel-OEM signal conditioner can be controlled directly using the “FOTEMP Assistant” software. Hence, complex temperature profiles can be realized and an excellent monitoring of the results is possible. On the back of the measuring device is an LED, which shows the system status.

The outer jacket of the fiber optic temperature sensors is made out of teflon, at the sensor tip a GaAs-crystal (gallium arsenide) is attached. The probe sensor is completely non-conductive. Optocon’s fiber optic sensors offer complete immunity to RF and microwave radiation with high temperature operating capability, intrinsic safety, and non-invasive use. The sensors are also designed to withstand harsh and corrosive environments. Due to its characteristics, it is perfectly suitable for installation in microwave or drying ovens.

Starting at a light wave length of 850nm GaAs becomes optical translucent. Since the position of the band gap is temperature dependent, it shifts about 0.4nm/Kelvin. The measurement device contains a light source and a device for the spectral detection of the band gap. This guaranties fast, repeatable and reproducible measurements.

Key Features

  • Easy OEM migration
  • Rugged and easy to use
  • Small footprint
  • Measuring range: – 200°C to + 300°C
  • Standard deviation*: +/– 0.2°C
  • RS-232, USB or Profibus DP interface


  • EMI, RFI and microwave environments
  • High voltage environments
  • Harsh and hazardous environments
  • Nuclear environments
  • Aerospace applications
  • Process monitoring
  • Medical applications (MRT)

Technical Specifications

Number of channels 1
Power supply 12 VDC, incl. power supply
Power consumption 350 mA
Display range – 200°C to + 300°C
Standard deviation* +/– 0.2°C
Resolution 0,1°C
Measuring time/Channel* 250 ms
Analog output 0 to 10 V or 4–20 mA (programmable) BNC
Communication RS-232 / RS-485 / USB
Calibration One-point calibration via software
Display none
Storage temperature – 20 °C to + 70 °C
Operationg temperature 0 °C to + 50 °C
Weight 0,5 kg
Dimensions 190 x 100 x 40 mm
Material Aluminium, Metallic
Software e.g. FOTEMP Assistant 2 or ASCII-Protocol-Description
Communication protocols ASCII over RS-232, USB
Warranty 2 years
Probes Compatible with all Optocon AG fiber optic temperature probes.
  *Further information can be found on the data sheet (PDF).