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supplied "K" factor then comparing the electronic totalized flow with the totalized value <br />on the mechanical McCrometer over extended run time. The K factors were then <br />adjusted in an effort to achieve outputs as nearly synchronized as possible. <br />Level measurement accuracies are a point of focus. With the open channel sites, it is a <br />straight - forward task to identify slope and offset values for the electronic sensors (multi - <br />turn potentiometers linked to a float & pulley apparatus). With these calibrated <br />constants, the radio /control equipment is able to make an accurate determination of water <br />level, and in turn of flow within the accuracy limits of the flow measurement structure. <br />There is greater uncertainty in the monitored pump flow. Propeller meter measurement <br />accuracy is difficult to verify without installation of an independent flow meter of known <br />accuracy in series with the propeller meter. Thus the system being employed on the J & <br />E alternate point of diversion wells is presently limited to the unknown accuracy of <br />installed propeller meters. <br />A potentiometer installed on a Stevens type F recorder is shown in Figure 4. A kit <br />available from Stevens enables a multi -turn potentiometer to be installed in the gear <br />mechanism of the type F recorder. Others who have utilized this kit report that they <br />typically needed to reset the offset on the potentiometer every time a new paper chart is <br />loaded, as it is common practice to loosen the thumb screw that tightens the pulley to the <br />shaft it rotates to adjust the chart to the existing flow level. For this project it was <br />reasoned that by attaching directly to the pulley, the relationship between float elevation <br />and potentiometer rotation would remain constant despite these chart- setting adjustments. <br />Figure 4. A Potentiometer Mounted to a Stevens type F Recorder Pulley <br />7 <br />