Kellyco XLT User Manual

Kellyco XLT User Manual Manual pdf 45 page image

44Chapter 5 XLT ® Pro Options23. D.C. PhaseMeasurement of the ground mineralization, ormeasuring the phase (V.D.I. reference number) of aspecific metal target during pinpointing.When D.C. PHASE is ON, and the TRIGGERsqueezed and released, normal searching begins.When a target is located, or when the operatorwants to measure a target or the ground, the TRIG-GER is squeezed and held as if to pinpoint. Whenthe loop is held stationary over the target or ground,the D.C. PHASE is shown on the upper-right sideof the display. The depth reading can be used tohelp center the loop over a target for more accurateindications. The audio tone will also assist incentering the loop over the target.Metal targets in the ground will produce a measure-ment which represents the target indication ± theground measurement. To measure the target alone,move the loop off to one side (being sure to holdthe loop directly on top of the ground mineral), andrelease and re-squeeze the trigger. Then move theloop back over the target. This should allow aproper D.C. PHASE reading for the target alone.The relationship between D.C. PHASE, GroundBalance, V.D.I. number and Discrimination iscomplex. Results are not always repeatable invaried ground conditions. Ground and target re-sponses can distort the detection field of the loop ina number of ways, by bending, reflecting, absorbingand thus altering the phase and amplitude thedetector measures. This in turn produces inconsis-tencies in the relationships of these features.D.C. PHASEONOFFTO CHANGE PRESS ENTER(Display section)Tips - In specific groundconditions, certain BasicAdjustments and ProOptions may producebetter performance. Bymeasuring the ground andtaking notes, such condi-tions may also be recog-nized in other areas anddealt with by using similarsettings.10.5"+ - 1 2 - + - + - 9 - + - + - 6 - + - + - 3 - + - + - 0-82.2The D.C. Phase of the ground has a relationshipto the proper Ground Balance setting. This is ofparticular interest to those who use the optionalCOARSE or FINE G.E.B. (Manual GroundBalance). Manual Ground Balance has a rangethat covers V.D.I. numbers from -95 - +10. AManual Ground Balance Coarse setting of 0equals a D.C. PHASE of negative -95. A Coarsesetting of 255 equals a D.C. Phase of +10. Asmentioned under COARSE and FINE G.E.B.,Ground Balance is not the same as EDITingthese V.D.I. numbers for REJECT. However, ifyour ground measures -90, ACCEPTing V.D.I. -90 will produce operational problems as thedetector will see the ground as a target. With thesame logic, if a target measures -90, and theground measures -90, and the detector is GroundBalanced to this -90 ground, such a target will bevirtually invisible to the detector. These conditionswould be extremely rare however; the point isthere must be a difference between the target andthe ground for the target to be detected.