Page 19 - Texas811 Magazine 2019 Issue 2
P. 19

CONTINUED FROM PAGE 13 ungrounded cables because the 480kHz can be benencial in riiany
. . . . capacitance creates a sort of pseudo circumstances, but like all good things

5*“ '“‘d ‘“ “““°‘l’"“°“ "‘ b’““$ ‘Nd ground that allows the signal to pass there is a downside. understanding
W" “'9 “‘‘‘’ “°‘ “MY “‘ be 5“’““d‘d' rrorn the conductor into the ground these limitations can still allow the

If there is no grounrl, or the grounrling and so completes the circuit back to the user to appreciate the benerits othigh
is poor, making a good ground transmitter. using the 480kHz inode frequency locate tones The two inain
connection at the application point and helps rletect these short, unearthed donrisirles are

checklng tor continuity is not going cable drops 1) H mm are my numb “why ‘hm
“’ he‘? ’T‘"“°” “’ ‘hm '5 “°“'}‘“‘ This is not the end ui the story as is a clanger that the "bleed off” eiiect
‘°’ “‘° “"5"” ‘° "W" “’ ‘f “'2'? “ ‘“ 4B0kHz can also be a great help in can also result in a "bleed on" etteet
g’°““d “‘ ‘1“ fa’ “*1 we “'}‘°“‘d “*9 “ detectin olrler cast iron i elines so r2tumn> si nal currents Iravelin I
““““‘“‘ ‘°“‘‘‘‘‘‘1“° "’ 5°‘ “‘° 5‘5““‘ “’ Man of these i elines  have throu h thi’ gound rna hitoh a rid:
‘”"" ‘° “'9 9"‘ °‘ ”“ Cab" “ ‘““Y 5“ in;ul);led 'olnIsp 1l"his electrical on otliiser utlfgzs resultiyn in rnulti le
‘h“‘ Y‘’“ “M1 “ “Ni” ‘W has EVE“ “ insulntlurll ina > be ares-ult ui cnrmdln si al aths These tend 1:132 sinall:r
high“ ““‘T“°“‘Y ‘W 3'“ 'YP‘‘“‘‘Y “*3 oints anrl nut: and bolts or because (E2 signals-Pso carehilloeatin techni ues
to help you on this one. Typical locate ‘ 1. ‘ : '5 ’ _ ’ 3" ’ . 5 q

. sea ing material used to ioin the pipes can help to identity the correct one.

““‘T“°“"‘° ‘°““ “’ b‘ ‘“ ‘}“ mg“ “f can create an insulated oint Either wa

51ZHz to 3ZkHz These lmquencles ‘hi, N bad MW; Em ‘D H!‘ em; (I m Yr 2) As the signal will "bleed off” over the
offer good signal to noise locates where ‘D mm ‘M Own!" 0‘ the x Y“: entire length ui the cable, the distance
goorl grounding is present. Have you Capadmm Effeéb Mp hm if the sigrial will travel along the cable
consirlered using something in the The bimd end’ although Po’“;bly or pipe will be less than that of a law
range oM8lJk.Hz fur poor grounding muimd M“ hgvs mm m wmz hequency signal lt should be noted
situationsz mm mg ‘mm Ugfig low fifiquency that using low trequency loeate tones
so why -I80kHz? well the answer is pipe detecting techniques does not " "‘_“"“Y“ 5.2”‘ “hm 5”“ g“’““‘‘” “E
that at 480k!-Iz the signal will "bleed get a goorl signal path but switching P‘“"“‘

off" the cable due to the disriabuted to 480k!-Iz allows the signal to use the M0,, have aaast,a,,, U, amt...” ,.t,.,at
capacitance of the cable to grounrl. capacitance of the jolnl to lump over the this amt]? or relnfcd IUpI(‘S,fEElV/1'09 to
There's no need to go into explanations insulated seetion. mitfnrf stew m‘: 5[z1Ie.b('rlz/e("Jv).mI.:'om.
of what this is, but suttice it to aay— A Wm D‘ Wm“ _ M W hm

‘he “‘5}“’ ”‘° ""‘1“°““>" ‘he g'°“‘°’ seen the use othigh ire uencies such

these etteets Now this helps with ’ ' ’ 5 q ’ ’

Before you dig,
‘ KNOW ihe T3015.
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Tllr Jrfl'l(t u/Rt dt tan 1» dw W Wlfl Ilfl ml HXMII III III!’
g ‘ ' ‘I ietrivmtcattea in me are prusum pipoittuuitl tainted
is I: ‘ ‘S lnotines mm sate yul lite and
, p; 9 prelml Ill -met: lfil and be
dug f at namaamm nu-mt nmlmtam
info@utasear(h.(om  wogg 5MAfiTERl_ on. ll-arrllanhunui
2019, !ssu22 ronsaii -17

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