OSI-S is an ultra-high distributed optical fiber sensing instrument. The principle is optical frequency domain reflection (OFDR). It has the characters of high spatial resolution and high accuracy. The measuring accuracy of OSI-S is ±0.1℃ or ±1.0 micro strain. We design experiments to verify the accuracy of the device’s measurement temperature.
Sensing optical fiber is 20m which was placed in an oil bath. The initial temperature of the oil bath was set to 30℃. Set temperature to 30.1℃ and 30.3℃ and wait for the temperature of the oil bath to be stable , Then measure the temperature of sensing fibers by OSI-S. The result is shown in figure 1.
Figure 1 Result of temperature
The red line is the result of the temperature distribution of the sensing optical fiber when the oil bath temperature is 30.1℃. The green line is the result of the temperature distribution of the sensing optical fiber. When the oil bath temperature is 30.3℃.
When the actual temperature is 30.1℃, the temperature of the sensing optical fiber fluctuates between 30.0℃ and 30.3℃, the average is 30.11℃. When the actual temperature is 30.3℃, the measured temperature fluctuates between 30.2℃ and 30.5℃, the average is 30.32℃. The above results show that OSI-S has high accuracy of temperature measurement. With many times of measurement and verification, the accuracy of OSI-S temperature measurement can reach ±0.1℃.