Th. Binkert

High-resolution distributed temperature sensing with the multiphoton-timing technique

We report on a multiphoton-timing distributed temperature sensor (DTS) based on the concept of distributed anti-Stokes Raman thermometry. The sensor combines the advantage of very high spatial resolution (40 cm) with moderate measurement times. In 5 min it is possible to determine the temperature of as many as 4000 points along an optical fiber with an accuracy Δ T < 2 °C. The new feature of the DTS system is the combination of a fast single-photon avalanche diode with specially designed real-time signal-processing electronics. We discuss various parameters that affect the operation of analog and photon-timing DTS systems. Particular emphasis is put on the consequences of the nonideal behavior of sensor components and the corresponding correction procedures.

A fast multi‐time‐interval analyzer with real‐time processing capability

We report on the prototype of a new digital multi‐time‐interval analyzer (MTIA‐1) based on a counter/memory architecture. The occurrence of multiple events with respect to a common start can be determined with a timing resolution of 4 ns. Incoming standard TTL or ECL pulses are processed and stored immediately after their detection in a 4096×16 Bit RAM. By virtue of this real‐time histogramming concept, data acquisition does not have to be interrupted during signal processing. The maximum repetition rate of events to be processed in real time can be in excess of 20 MHz. The MTIA‐1 is designed for repetitive timing applications where multiple time intervals have to be processed with very high speed. The analyzer accepts standard TTL or ECL pulses and has a maximum measurement range of 4096 channels. After the end of an individual multi time interval measurement no additional time consuming postprocessing is needed for data transfer or data analysis. The article gives an overview of the structure of the ana...