Tinker & Rasor APS User manual

How$to$Use$a$Holiday$Detector$
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Holiday(Detection(
The$premature$corrosion$of$a$substrate$is$usually$due$to$a$coating$failure$which$is$largely$from$
flaws$in$the$finished$coating.$Holiday$tests$are$used$to$detect$holes,$known$as$holidays$or$
breaks,$in$a$coating.$Holiday$testing$allows$the$detection$of$even$the$smallest$coating$flaws$
invisible$to$the$naked$eye.$$
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Holiday$detection$equipment$offered$by$USI$is$safer,$faster$and$more$reliable$than$ever$before.$
There$are$various$kinds$of$holiday$detectors$on$the$market$today,$but$high$voltage$holiday$
tests,$or$porosity$techniques,$is$ideal$for$inspecting$pipelines$and$other$protective$coatings.$
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The$Tinker$&$Rasor$Model$APS$Holiday$Detector$is$an$all-purpose$electrical$inspection$
instrument$which$maintains$a$given$inspection$voltage$despite$the$electrical$load$on$the$circuit,$
this$is$also$known$as$DC$pulse$holiday$detection.$This$specific$model$supplies$800V$to$35kV$in$
one$instrument$with$two$ranges$of$3,500V$to$35,000V$and$a$low$range$of$800V$to$8,000V.$It$is$
recommended$for$use$on$any$pipe$diameter$as$well$as$on$flat$surfaces.$$
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Tinker(&(Rasor(Model(APS(
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Unpacking(and(Set-up(
Inspection$should$be$made$upon$receipt$to$ensure$that$all$parts$were$received$unscathed$and$
every$piece$of$your$equipment$is$in$working$order.$First$remove$all$accessories$from$the$
shipping$carton,$then$connect$the$high$voltage$wand$handle$to$the$front$of$the$instrument$and$
ground$cable$to$the$detector$handle$by$inserting$it$and$twisting$it$clockwise.$Never$connect$or$
disconnect$the$cable$or$wand$when$the$instrument$is$turned$on.$
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Ensure$all$the$accessories$are$in$the$kit$by$going$through$the$following$checklist:$
o APS$instrument$$$$$Two$batteries$
o Mil-spec$waterproof$carrying$case$ $ $Compax$connector$for$full$circle$electrodes$
o 4”$rubber$paddle$electrode$ $ $20’$ground$cable$
o Voltage$adjusting$screwdriver$ $ $18”$wand$handle$with$full$circle$spring$electrode$connector$
o Instruction$Manual$$$$Battery$charger$
o One$electrode$(3$versions$to$choose$from)$ $
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Next$attach$the$electrode$to$the$high$voltage$wand$handle$assembly$and$apply$it$to$the$
structure$to$be$inspected.$The$electrode$should$always$make$close$contact$with$the$surface$
under$inspection.$From$this$point$the$detector$is$ready$to$turn$on$and$test.$Turn$it$on$by$holding$
the$safety$switch$handle$firmly$against$the$instrument$handle,$where$the$rubber$grip$is$located,$
and$then$press$the$on$button.$The$holiday$detector$will$turn$off$when$the$safety$handle$is$
released.$The$three$choices$listed$in$the$kit$are$as$follows$with$more$choices$to$attach$sold$
separately:$
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Electrode$Choices$for$The$Tinker$&$Rasor$APS$Holiday$Detector$Kit$
Electrodes(
Full$and$half$circle$electrode$springs$are$made$stainless$steel$for$resistance$to$roll$down$pipe.$
Half$circle$springs$have$190-degree$arc.$These$types$of$electrodes$are$ideal$for$inspecting$
pipeline$coatings$in$a$plant$or$the$field.$These$are$square$cut$and$tightly$wound$for$tight$fit$and$
intimate$contact$to$coatings$and$will$inspect$the$entire$coated$surface$of$the$pipe$in$one$pass.$
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Silicone-rubber$electrodes$are$made$of$conductive$material$with$very$low$resistivity,$a$unique$
combination$of$silicone$rubber$and$carbon.$It$meets$many$different$requirements$and$
applications$and$it$is$used$to$inspect$welds,$tanks,$rail$cars,$concrete$structures$or$other$
conductive$substrates$with$non-conductive$coatings.$$
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Wire$brush$electrodes$are$made$of$crimped$stainless$steel.$It$meets$many$different$
requirements$and$applications,$especially$for$coated$surfaces$that$are$uneven$or$include$
fittings,$bolts,$or$other$tight$corners$need$to$be$inspected.$It$is$best$used$for$coatings$with$
irregular$surfaces$or$joints,$fittings,$ect.$
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Sponge$electrodes$are$only$used$with$low$voltage$holiday$detectors$for$rapid$wetting.$
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External$Electrodes$
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Operation(
Once$you$turn$the$holiday$detector$on$you$can$adjust$the$voltage$using$the$screwdriver$
supplied$in$your$kit$after$pushing$the$high$or$low$setting$buttons$to$pick$your$range.$The$voltage$
you$should$use$is$dependent$on$the$dielectric$strength$and$thickness$of$the$coating$being$tested$
or$the$test$method$or$standard$you$are$working$to.$Please$see$the$voltage$section$for$details.$
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After$adjusting$the$voltage$recommended$for$your$substrate,$attach$the$ground$cable$to$the$
holiday$detector.$If$after$running$the$test$all$seems$well$get$ready$to$contact$the$electrode$to$
the$substrate$surface.$If$not$you$may$need$to$clip$the$ground$cable$to$an$uncoated$section$of$
the$substrate$being$tested.$When$testing$on$concrete,$either$hammer$a$masonry$nail$or$
conducting$spike$into$the$concrete,$or$use$any$exposed$uncoated$rebar.$In$some$instances,$you$
can$simply$use$a$grounding$mat$as$a$larger$trailing$lead,$aiding$in$the$grounding$when$in$drier$
conditions,$depending$on$the$substrate.$The$grounding$cable$alone$should$work$fine$in$most$
cases$unless$the$environment$is$very$dry.$
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Place$the$live$electrode$on$the$test$surface$and$move$it$over$the$work$area$at$a$constant$speed,$
as$defined$by$the$test$method$or$standard$you$are$working$to.$Always$be$sure$to$switch$off$the$
instrument$before$disconnecting$any$cables.$The$speed$of$the$electrode’s$travel$along$the$pipe$
should$never$be$excessive,$since$faulty$inspection$may$result.$$
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Model$APS$High$Voltage$Holiday$Detector-Portable$Stick$Type$
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Testing(
Occasional$checks$of$the$detector$operation$should$be$made,$particularly$if$no$holidays$are$
being$found.$This$can$be$accomplished$by$testing$for$the$spark$and$signal$at$the$degree$of$the$
coating$where$bare$pipe$exists$or$by$touching$the$probe$end$to$the$bare$pipe$and$noting$the$
length$of$the$spark$and$the$visual$and$audible$signal$effectiveness.$If$the$visual$and$audible$
signal$do$not$both$occur$when$the$spark$discharges$from$the$electrode$into$a$known$holiday,$
the$ground$return$(path$between$the$metallic$pipe$and$earth$and$the$earth$to$the$ground$trail$
of$the$detector)$is$of$high$resistance.$In$this$case,$a$better$ground$is$required$and$a$direct$
grounding$is$extremely$uncommon$unless$the$soil$is$very$dry$or$the$detectors$output$is$low.$

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Voltage(
The$voltage$used$to$test$should$be$high$enough$so$that$in$areas$where$the$coating$is$electrically$
weaker,$due$to$a$flow$or$discontinuity,$there$is$sufficient$voltage$to$break$down$the$gap$or$
insulation$between$the$probe$and$the$substrate.$When$this$breakdown$occurs$the$current$flows$
from$the$probe,$through$the$substrate$and$back$into$the$holiday$detector,$completing$a$circuit$
and$thereby$triggering$an$alarm$to$signal$a$flaw$has$been$detected.$As$the$high$voltage$method$
can$locate$any$area$where$the$coating$is$weaker$than$specified,$this$method$allows$you$to$
detect$flaws$that$don’t$go$all$the$way$down$to$the$substrate,$such$as$cratering$for$example,$as$
well$as$voids$within$the$coating.$$
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The$Tinker$&$Rasor$APS$Holiday$Detector$includes$an$integrated$voltmeter$displayed$on$the$
front$panel$of$the$main$instrument.$The$LCD$screen$of$the$voltmeter$measures$and$displays$the$
output$voltage$of$the$holiday$detector.$This$display$gives$the$user$the$ability$to$tune$the$APS$to$
a$specific$voltage$with$in$increment$in$100V$steps.$
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Correct$voltage$output$for$a$given$thickness$of$coating$has$long$been$a$matter$of$controversy.$
However,$recent$formulas$have$been$suggested$which$may$be$used$as$a$guide$for$correct$peak$
voltages$on$various$coating$thickness.$The$calculation$is$as$follows:$
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NACE(International(Standard(RP0274,(RP0490(Formula(
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These$formulas,$when$applied$to$a$coating$of$3/32”$thickness$and$with$a$constant$of$1,250,$
would$indicate$an$applied$voltage$of$12,500$volts$peak$or$a$coating$of$16$mil$thickness$with$a$
constant$of$525$would$indicate$an$applied$voltage$of$2,100$volts.$A$common$practice$used$in$
setting$inspection$voltages$in$the$field$is$to$adjust$the$output$voltage$by$visual$observation.$It$is$
the$consensus$that$spark$discharge$at$least$twice$the$thickness$of$the$coating$will$give$adequate$
inspection$voltage$and$compensate$for$determining$inspection$voltage,$it$should$be$done$while$
the$electrode$is$in$the$normal$operating$position$and$under$actual$grounding$conditions.$
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Calibration(
The$model$APS$voltmeter$is$accurate$to$+/-$5%$of$the$output$voltage,$as$shown$on$the$LCD$
display$on$the$instrument$panel.$It$is$recommended$that$this$model$follow$an$annual$calibration$
cycle$to$ensure$the$instrument$is$in$good$working$order$and$that$the$LCD$of$the$integration$
voltmeter$is$accurate.$
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Battery(Charging(
The$Model$APS$comes$with$two$batteries.$The$lithium-ion$battery$should$be$charged$after$each$
use.$The$Model$APS$will$indicate$when$the$battery$voltage$is$low,$by$a$slow$blinking$of$the$
Green$Power$LED,$instead$of$providing$a$steady$glow.$The$battery$charger$has$an$LED.$RED$color$
LED$indicates$the$battery$is$being$charged.$GREEN$color$LED$indicates$that$battery$is$fully$
charged.$GREEN$color$LED$also$means$that$the$battery$is$on$trickle$charge,$and$can$be$left$in$
this$condition.$The$charger$can$be$used$with$110v$/$240v$AC.$It$is$an$auto$sensing$charger$that$
can$be$used$throughout$the$world.$Please$consult$your$manual$if$you$have$a$battery$with$a$
serial$number$prior$to$827.$
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