About Depths

Drill depth by pressure is calculated using a pressure sensor inside the drill head. The reported depth is the distance between the top of the water column and the drill head. If you want depth relative to the floor of the tower you have to add in the well depth at the time of the measurement. You should try to get this measurement but if it is not available then an approximate value you could use is 40 meters. Also you should add in the length of the drill weight stack which is 25.86 meters.

Depths by payout are to be reset to zero when the top of the drill head is at the floor of the tower. To get depths to the drill nozzle add in the length of the weight stack which is 25.86 meters. Payout depths come in two separate flavors. These are payout at tower and payout at drum. Payout at tower values are generated using an encoder mounted at the top of the drill tower. Payout at drum are calculated by the unico. It is suggested that you look at the payout at tower values. There are two payout at tower values available. One for the hose and one for the cable. Look at both of them and to be conservative pick the one with the lowest value.