High-Speed Digitizer for Distributed Temperature Sensing

Temperature detection is vital for its added security value in applications such as subway/metro tunnels, mining, warehouse, and oil & gas facilities. The traditional method of measure temperature is to deploy measurement devices at specific locations. This is not practical when the area to measure spans several miles. Distributed temperature sensing (DTS) is a technology based on optical time domain reflectometer (OTDR) technologies. DTS systems can measure temperature profiles along optical fibers with lengths of up to 37 miles and obtain thousands of accurate temperature measurements.

Within a DTS system, a laser pulse is coupled to an optical fiber. Light is backscattered as the pulse propagates through the fiber. The wavelengths of the light are affected by temperature changes at certain positions. By measuring the difference in the signal intensity of the backscattered light with high precision, an accurate temperature measurement can be made. When dealing with such high speed signals, a high-speed and high-resolution digitizer plays an important role in this application. The sampling rate of the digitizer determines the spatial resolution and its dynamic performance determines the temperature resolution.