To continue a discussion started in this thread , I would like to open a new thread.
Knowing that all depth measuring methods have error margins :
1. Are these error margins small enough to be able to maintain the current 1 meter increment for depth world records (and non record dives).
2. How can we improve the accuracy (and if needed get the error margin below 1 meter).
3. If current measurements do have an error margin larger then 1 meter, shouldn't we adjust the minimal depth increment for new records to be larger then the maximum error margin of the measurement (to make sure the new record is in fact deeper than the old one and not shallower)?
We can identify 2 basic measuring methods currently used. Both with their flaws and strengths.
a. Using distance to measure depth e.g. measuring the line after sufficient calibration and pre-stretching. A line is prone to stretch under continuous load of its own weight and the bottom weight. Different materials react different specially when wet. Turtle already suggested to use a material called Vectran, which looks like a good candidate. What are the error margins and stretch properties of currently used WR cables ??
Also the angle of the line , specially at record depth , can create errors.
b. Using pressure to measure depth (indirect method). This methods seems prone to errors caused by differences in the composition of the water column that generates the total measured ambient/hydrostatic pressure. Think of different densities , temperatures , salinity, currents and the accuracy of the pressure measurement itself. Maybe Eric Fattah can shed some light on this subject with the currently used dive computers.
Using both methods at the same time can theoretically both reduce but also increase the error margin.
Since I am not an AIDA judge, maybe some judge can explain how they perform and check the exact measurement in practice.
Knowing that all depth measuring methods have error margins :
1. Are these error margins small enough to be able to maintain the current 1 meter increment for depth world records (and non record dives).
2. How can we improve the accuracy (and if needed get the error margin below 1 meter).
3. If current measurements do have an error margin larger then 1 meter, shouldn't we adjust the minimal depth increment for new records to be larger then the maximum error margin of the measurement (to make sure the new record is in fact deeper than the old one and not shallower)?
We can identify 2 basic measuring methods currently used. Both with their flaws and strengths.
a. Using distance to measure depth e.g. measuring the line after sufficient calibration and pre-stretching. A line is prone to stretch under continuous load of its own weight and the bottom weight. Different materials react different specially when wet. Turtle already suggested to use a material called Vectran, which looks like a good candidate. What are the error margins and stretch properties of currently used WR cables ??
Also the angle of the line , specially at record depth , can create errors.
b. Using pressure to measure depth (indirect method). This methods seems prone to errors caused by differences in the composition of the water column that generates the total measured ambient/hydrostatic pressure. Think of different densities , temperatures , salinity, currents and the accuracy of the pressure measurement itself. Maybe Eric Fattah can shed some light on this subject with the currently used dive computers.
Using both methods at the same time can theoretically both reduce but also increase the error margin.
Since I am not an AIDA judge, maybe some judge can explain how they perform and check the exact measurement in practice.
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