Ridge CountingThe process of counting the ridges that touch orcross the line of count drawn between the delta and core of loop patterns. A white space mustalways intervene between the delta and the first ridge to be counted.
Ridge CountThe number of ridges intervening between the delta and core.
Rules in Ridge Counting Locate the exact points of the core and delta Count all the ridges which touch or cross an imaginary line drawn between the core and delta Never include the core and delta in counting. Count only those ridges which intervene or pass the imaginary line of count of line Incipient ridges are never counted no matter where they appear. The general rule is that in order to be counted, the width of a ridge must be equal to the width of the other ridges in the pattern under consideration.
Ridges included in ridge counting and their numerical value: An island ridge or dot ridge is given one ridge count A short ridge is given one ridge count A long ridge is given one ridge count An abrupt ending ridge is given one count If a ridge bifurcates into two across the imaginary line, the ridge count is two If the point of origin of a bifurcating ridge is on the line of count, the ridge count is two
If the legs of enclosure or eyelet ridge is on the line of count, the ridge count is two If the intersection of two enclosures is on the line of count, the ridge count is two If the intersection of two enclosures is on the line of count, then the ridge count is four When the core is located on ending ridge which touches the inside of the innermost re-curving ridge, the recurve is included in counting only when the delta is located below a line drawn at right angle to the end or tip of such ending ridge
Ridge Counting in Whorl PatternsWhorl patterns are counted only if they appear in the little fingers of both hands. If there is no loopin the eight fingers (little fingers not included), the first whorl is to be counted to obtain the key classification formula
A plain whorl and central pocket loop are treated as an ulnar loop A double loop (twinned loop) is counted to an upright loop An accidental whorl is counted from the extreme corresponding delta to the nearest core (least number of ridge count) The counting in a lateral loop is made between the lower delta and the nearer loop regardless of whether the print is found on the left or right hand.
Ridge TracingThe process of coursing or tracing the ridge thatoriginates from the left delta flowing towards theright delta or near the point and determining thenumber of intervening ridges between the traced ridge and right delta to constitute the three subdivisions such as inner, meeting and outer presented by capital I, M, O.
Rules in Ridge Tracing When the deltas have been located, the tracingstarts on the ridge emanating from the lower side or point of the left delta until the point nearest or opposite the right delta is reached. Then the number of ridges intervening between the tracedridge and the right delta are counted to determine whether it is inner (I), meet or meeting (M) or outer (O).
If the traced ridge ends without reaching the right side, it is necessary to drop perpendicularly to a point on a ridge directly below and continue the tracing up to the relative point nearest the right delta.
If the traced ridge is a bifurcation, follow the lower branch and if this branch ends abruptly, drop on the next ridge until tracing is completed.
Inner Whorl (I) If the traced ridge reached the relative pointnearest the right delta and goes above or inside it and there are 3 or more intervening ridgesbetween the traced ridge and the right delta, it is considered as an inner whorl.
Meet or Meeting Whorl (M) A whorl pattern is considered meet or meeting ifthe traced ridge reached the relative point nearestthe right delta and goes above/ inside; or below/ outside with 1 or 2 intervening ridges between such delta and traced ridge, or if the traced ridge started from the left delta and runs directly to the right delta.
Outer Whorl (O) A whorl pattern is considered outer if the traced ridge reached the relative point near the rightdelta and goes below or outside such delta with 3 or more ridges intervening between such delta and traced ridge.