Posted by jorge uruchurtu on September 26, 1996 at 10:27:18:
In Reply to: Squiggly lines ... posted by Karel Hladky on July 21, 1996 at 17:53:07:
: Come on, surely you can do better than say that this
: noise trace was squigglier than that one.
: The absolute Ecorr's in Figs 3 - 5 seem a bit high
: for galvanised steel, then again there isn't much zinc
: left judging by the photos.
: What surface area did you use for the Rp calculations
: - or are these for the whole of the leg in question ?
SECOND QUESTION FIRST, WE DIDNīT CONSIDER A SURFACE
AREA FOR CALCULATIONS,WE ASSUME THE SAME AREA SINCE
ALL TOWER LEGS WERE OF THE SAME DESIGN. THE CURRENTS
SHOWN ARE ABSOLUTE AND NOT CURRENT DENSITIES.
THE OTHER QUESTION THE NOISE TRACES IN FIGURES 3 AND 5
CAN BE COMPARED SINCE THE SCALE IS OF THE SAME AMPLITUDE.
THERE APPEAR CERTAIN QUALITY DIFFERENCES IN THE TRACES.
NEVERTHELESS THE NOBLE POTENTIALS ARE ASSOCIATED TO THE
PRESENCE BASICALLY OF STEEL WITH NO GALVANIZED (AFTER
WARDS CORRELATED AFTER EXCAVATION).POTENTIALS MORE NEGATIVE
THAN -900 MV RELATES TO ZINC ACTIVITY. BIUT THE TROUBLE
STARTS WITH POTENTIALS BETWEEN -500 AND -800 WERE IS NOT
CERTAIN THAT YOU HAVE EITHER CORROSION ACTIVITY OF STEEL
OR YOU CONTINUE WITH A CERTAIN CP PROTECTION OF ZINC
(ILLUSTRATED IN FIGURE 4).THIS PRELIMINARY FIELD TRIALS
WERE MADE IN ORDER TO TRY TO ESTABLISH CERTAIN CRITERIA
FOR MAINTENANCE PURPOSES. MUCH WORK IS NEEDED UNDER CONTROLLED
LABORATORY CONDITIONS TO SEEIF THOSE SQUIGGLY LINES REALLY
RELATE TO THE DIFFERENT CONDITIONS ENCOUNTERED(ZINC, GALVANIC,
AND STEEL ACTIVITY).