IoT Sensors Monitor a 1,400-Kilometer Canal in China

Re:IoT Sensors Monitor a 1,400-Kilometer Canal in China by stagger87 on Friday January 12, 2018 @03:06PM (#16135882)

If you're interested, optical time-domain reflectometers are used to characterize fiber cables, including breaks/bends/faults/etc. Pretty standard and relatively cheap test equipment.

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Re:IoT Sensors Monitor a 1,400-Kilometer Canal in China by wlesieutre on Friday January 12, 2018 @03:49PM (#16136180)

I was curious how accurate those are, found a datasheet for the PRO-OBL-201A ($1600, or effectively nothing compared to an oil pipeline). It's a portable "optical break detector", full blown reflectometers might have more features.

They list the maximum range as 100 Km, with accuracy of +/- (0.8 m + 0.001% x Distance). So measuring to a break at maximum range, you'll be within 1.8 meters.

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Re:IoT Sensors Monitor a 1,400-Kilometer Canal in China by sharpercoder on Friday January 12, 2018 @09:08PM (#16137867)

iirc, tunnels use this to know where exactly fires occur.

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