YOKOGAWA DTSXL, User Manual, Page: 71 / 289

< PART – A Hardware >
A-48
IM 39J06B40-01EN 14th Edition: May 30, 2022
A5.4. Routing and Connecting a Sensor Optical
Fiber
A5.4.1. Measurement
You can configure the DTSX3000 to perform single-ended measurement or double-
ended measurement. In double-ended measurement, the sensor optical fiber needs to
be looped back, which halves its effective measurement distance. However, it is an
effective measure against unknown sensor optical fiber loss or sensor optical fiber
darkening.

Single-ended Measurement
The figure below shows an example of a connection for single-ended measurement. In
this example, two channels are measured. If only one channel is to be measured, an
optical switch (DTOS) is not required. In multi-channel measurement, an optical switch
(DTOS) can be purchased as an option and installed to enable auto-switching between
channels during measurement according to a user-defined measurement sequence.

Double-ended Measurement
The figure below shows an example of a connection for double-ended measurement. In
double-ended measurement, the sensor optical fiber is looped back to an optical switch
(DTOS) to form a loop configuration. Signals from the DTSX3000 use 2 channels of the
DTOS to measure one system. The two DTOS channel ports must be defined as the
near end and far end respectively. Measurement data is processed using the channel
name of the channel configured as the near end. Uniform temperature sections (10 m or
longer) can be optionally configured on the near-end and far-end of the looped sensor
optical fiber such that the sections are subjected to the same temperature for calibration
purposes. If this option is used, the DTSX3000 performs sensor optical fiber loss
calibration at each measurement so that the impact on temperature measurement of any
sensor optical fiber darkening or any change in sensor optical fiber loss during
temperature measurement is minimized.
Sensor Optical Fiber