Well Cable Length
Measurements
Apparent cable length as reported by the TDR device
Distance from surface to static water level
Parameters
Velocity of propagation set on the TDR device
Saved from calibration — edit to override
Saved from calibration — edit to override
Calibration
Velocity of Propagation Ratio
With the pump already in water, submerge a known length of main cable and record TDR readings before and after. This determines Vpwater / Vpair.
Pump in water, cable still in air
After submerging the cable
Main cable only, not pump leads
The pump body can add phantom apparent length to the TDR reading when submerged. Record the TDR before and after submerging only the pump and its leads to quantify this offset.
Everything in air
Pump and leads only, cable in air
Pump lead length submerged