The signal for the parameter Hook Load is collected from the hydraulic system of the rig by using related sensors. The WOB is calculated as the difference between "free" string weight and hook load during normal operation. For obtaining this parameter in a good quality the used sensors have to have a very high linearity and reproducibility.
Besides hardware filters there exist software filters too, to get the real WOB without the normal disturbances of the Hook Load signal. For calibration there exist an easy to operate menu on the GEOCOMP-3.
The WOB is recorded on the time printer. The GEOCOMP DATA TERMINAL records the WOB too on its hard disc and allows displaying and printing versus time and depth together with other parameters.
WOB as well as Hook Load is displayed on the GEOCOMP-3 and on the DATA TERMINAL.
