NACE SP0188 - ANSWER High and Low Voltage Holiday Testing
Low-Voltage Holiday Detector - ANSWER -Ground is attached directly to substrate.
-Sponge saturated with a solution of tap water/wetting agent
-Proper mix ratio 1oz/USgal
-Proper of speed is 1ft/sec Double Stroke
-Used on Coatings up to 20mils
-may be used on concrete
Low Voltage Holiday Detectors Common Errors - ANSWER -Failure to Keep probe in con-
tact with surface
-Moving the electrode too fast or slow
-Over or under saturating the sponge
-Low battery or bad lead/ground connection
Telegraphing - ANSWER Can occur when surface is saturated with water and the Detector
reads a different area.
High Voltage Holiday Detectors - ANSWER -Can have an Output range from 800-60,000v
-In General Voltage ratio 100v/1mil
-Electrode Rate of 1ft/sec with a single pass
-Ground connection must be made direct to metal substrate(preferred) or indirectly for pipe-
line in soil.
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Low-Voltage Holiday Detector - ANSWER -Ground is attached directly to substrate.
-Sponge saturated with a solution of tap water/wetting agent
-Proper mix ratio 1oz/USgal
-Proper of speed is 1ft/sec Double Stroke
-Used on Coatings up to 20mils
-may be used on concrete
Low Voltage Holiday Detectors Common Errors - ANSWER -Failure to Keep probe in con-
tact with surface
-Moving the electrode too fast or slow
-Over or under saturating the sponge
-Low battery or bad lead/ground connection
Telegraphing - ANSWER Can occur when surface is saturated with water and the Detector
reads a different area.
High Voltage Holiday Detectors - ANSWER -Can have an Output range from 800-60,000v
-In General Voltage ratio 100v/1mil
-Electrode Rate of 1ft/sec with a single pass
-Ground connection must be made direct to metal substrate(preferred) or indirectly for pipe-
line in soil.
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