July 30, 2024
The AT system displays readings as mm or inches of tilt, and this reading applies at the depth of the top wheels. Scroll downwards to see a technical explanation with a graphic. Classic cable marks are measured from the middle of the probe, but this has some unexpected effects when readings are plotted:
Metric Plots:
- AT system: A reading taken at 10 m is correctly plotted at 10 m, as you would expect.
- Classic system: A reading taken at 10 m is correctly plotted at 9.75 m, which you would not expect.
English Plots:
- AT system: A reading taken at 30 feet is correctly plotted at 30 feet, as you would expect.
- Classic system: A reading taken at 30 feet is correctly plotted at 29 feet, which you would not expect.