No probes or wires need go down-hole to get hung up or broken off. Operates during a pump test. The unit will measure 2” or larger wells, even capped wells that have a 5/8” or larger access hole. Accuracy is to within 1/10 of 1% of the total depth of the water.
Instead of introducing foreign objects into a well, the SONIC method uses the air in the well to send an acoustic signal down to the water surface. The sonic signal is injected from the meter duct into the well casing through a top opening in the well cap of 5/8-inches or greater in diameter. The signal reflected from the water surface is then detected and the round-trip time measured. Multiplying by the velocity of sound and dividing by two, gives the depth-to-water in feet, or meters in the metric mode.
The Depth Switch optimizes the measuring capability for deeper wells. Using this setting reduces the possibility of false returns from the end of the casings that go into rock, from wire shields, torque arresters, and similar obstructions at the upper end of the well.
For the best accuracy, it is necessary to compensate for the variation of sound velocity with well air temperature. The Temperature setting control adjusts for the variation, which is approximately 0.1 per degree F. The unit remembers the last setting used.
The Regional Map Table or the Look Up Table can help provide the appropriate temperature setting. This value is easily set into the meter by using the up-down toggle switch and shows continuously on the display. Regional Map Tables are available for the entire US. The water temperature should be measured and the Look-Up Table used in the regions where geothermal activity or other anomalous subsurface conditions exist.
Includes a hard plastic, foam lined case with adaptors for uncapped wells and instructions. Complete one year warranty.
The Model 300 Dl has all the same features as the 300 but with the ability to Datalog information.