Micronor (Camarillo, CA) and Optocon AG (Dresden, Germany) have collaborated to create the FOTEMP1-OEM-MNT; a low cost, small form factor, single channel signal conditioner that seamlessly integrates Fiber Optic Temperature Sensing into any industrial control system, medical instrumentation or other OEM design. The standard FOTEMP1-OEM-MNT controller features include a calibrated measurement range of -40°C to +300°C and built-in USB, RS232 and SPI interfaces.
The product operates in conjunction with all TS Series GaAs Fiber Optic Temperature Sensors to provide a discrete temperature monitoring solution that can operate accurately and reliably in challenging environments where electronics-based temperature sensors (thermocouples, RTDs) cannot function. The fiber optic sensor’s entirely non-metallic, passive optical design provides immunity to electromagnetic interference (EMI), radio frequency interference (RFI), microwaves, high voltage, extreme magnetic fields, radiation, chemicals, and explosive atmospheres. In these environments, GaAs fiber optic temperature sensors enable new and unprecedented solutions impossible for electronic sensors.
Typical applications include monitoring temperature inside high voltage transformers and switchgear, MR imaging, semiconductor manufacturing, petrochemical plants, as well as microwave ovens and reactors used in food industry, material processing and bioengineering. The use of low loss optical fiber allows interference-free, remote temperature monitoring up to 2000 meters. Such distances are characteristic of mines, tank farms and downhole applications.
The temperature sensor’s operation is based on the inherent temperature dependency of the bandgap of the Gallium Arsenide (GaAs) semiconductor crystal. A continuous broadband light source is coupled into the sensor’s large core 200µm optical fiber which illuminates a Gallium Arsenide (GaAs) crystal mounted on the sensor’s fiber tip. GaAs absorbs wavelengths below its bandgap and the sensor reflects the wavelengths above. The transition region between the reflected and transmitted spectrum, i.e. the bandgap spectral position, corresponds to absolute temperature.
The FOTEMP1-OEM-MNT is a compact OEM interface solution with sophisticated functionality. The unit sources the broadband light to the GaAs sensor and an internal optical spectrum analyzer evaluates the reflected optical signal to determine the corresponding absolute temperature. This sensing and interrogation method allows for lower cost, greater accuracy (±0.2ºC), widest measurement range (-200°C to +300°C), and faster response compared to other fiber optic sensor techniques, including fluorescence decay and fiber Bragg gratings.