High Temperature FBG Sensor for Harsh Environments


WISTHEAT is a distributed high temperature sensor based on Fiber Bragg Grating (FBG) technology. The extreme long term stability of less than 1 °C per year at 600 °C makes it ideal to use in harsh environment industries and processes. By multiplexing several WISTHEAT thousands of sensing elements covering small or large areas can be accomplished. Compared to thermocouples WISTHEAT provides faster response time, improved accuracy, smaller form factor and insensitivity to EMI.


High Temperature Operation

The long term stability up to 600 °C – even for the most advanced FBG arrays – can be guaranteed using a unique grating writing and assembly process. The highest temperature range is available with steel buffer and up to 300 °C is available also with polyimide buffer.

Hand touching proximion's FiBER OPTIC SENSORs - Wistheat

Hand touching proximion's FiBER OPTIC SENSORs - Wistheat

Image created with 39 fiber optic sensors creating 2,660 thermal pixels

Image created with 39 fiber optic sensors creating 2,660 thermal pixels


High Spatial Resolution

Each sensor handles 1 to 100 FBGs. The number and placement of FBGs along the WISTHEAT sensor is fully configurable. Standard configuration is equidistant spacing of 5 mm. Despite the high FBG count and customizable FBG spacing the WISTHEAT sensor is produced without any splices between the FBGs.



Fast Response Time

Advanced packaging technology allows for a thermal constant of 70 ms for our standard package. The fast response time is also valid for the most advanced configuration with regards to sensor density and temperature operation.



Small Form Factor

WISTHEAT sensors can be installed in industries where it previously has not been possible to measure. Outer diameter wtih steel capillary is standard 800 μm and optional down to 250 μm.



All WISTHEAT sensors can be designed for extreme temperature, ionizing radiation, mechanical vibration, dust or EMI. We have experience of suitable fiber coatings, buffer materials, connectors and cabling.