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CIP Level 1 Section 21 > Low Voltage Instruments > Flashcards

Low Voltage Instruments Flashcards

1
Q

The four general types of holiday detectors are?

A

Low Voltage Holiday Detector.
High Voltage Holiday Detector.
High Voltage Constant Current DC Holiday Detector
High Voltage AC Holiday Detector.

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2
Q

Holiday testing is performed to find defects in coating films such as?

A

Pinholes
Fisheyes
Cratering
Nicks

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3
Q

Correcting coating defects is essentially important for items meant for?

A

Immersion or Buried service.

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4
Q

Cissing is also known as?

A

Fisheyes and Crawling.

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5
Q

Cissing, Fisheyes, and Crawling are terms for ___ ___ in the film that ___ the ___?

A
  1. Surface breaks in the film.

2. Reveal the substrate.

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6
Q

Cissing, fisheyes, and Crawling are often the result of?

A

Grease/Oil contamination on the substrate.

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7
Q

Cratering is the result of?

A

Air released from the surface of the coating, at a point where the coating is partially cured, so the coating does not flow back to cover the void.

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8
Q

Low Voltage Holiday Detectors are only able to detect ___ in the coating that go through to the substrate.

A

Holes

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9
Q

High voltage Holiday detectors can detect 1___ in the film that 2___ ___ penetrate to the conductive substrate.

A
  1. Weaknesses

2. Do not.

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10
Q

Two examples of conductive substrates are?

A

Metals and wet concrete.

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11
Q

Specification should indicate the points in the job when holiday testing is required. The coating should be reasonably 1___ but not 2___ ___ before testing is done.

A
  1. Cured

2. Fully cured. This is for ease of repair.

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12
Q

Coatings that are not cured may show 1___ ___. In fact, 2___ ___ in coatings may create weak spots of low 3___ ___ that 4___ ___ detectors may disrupt creating holidays where none previously existed.

A
  1. False Holidays.
  2. Solvent remaining.
  3. Electrical Resistance.
  4. High voltage
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13
Q

Despite the drawbacks, in some cases, like with 1____ ____ or 2___ ___ ___, the user may elect to test the coating before 3___ ___ so that any repair material would effectively bond to the underlying coat.

A
  1. Baked Phenolics.
  2. Glass-flake Epoxies.
  3. Final cure.
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14
Q

Holidays should be repaired as correcting coating defects is especially important for items intended for 1___ or ___ service. Repair defects then test again to ensure repairs were successful.

A
  1. Immersion or buried service.
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15
Q

Low Voltage Holiday detectors are 1___, ___ ___, ___ ___, ___ ___ powered by batteries with output voltages ranging from 2_ to _ __ ___ depending on the manufacturers circuit design.

A
  1. Sensitive, low voltage, wet sponge, electronic devices.

2. 15 to 120 Volts DC

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16
Q

These are Sensitive, low voltage, wet sponge, electronic devices.
2. 15 to 120 Volts DC.

A

Low Voltage Holiday detectors.

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17
Q

These range from 15 to 120 volts DC.

A

Low Voltage Holiday detectors.

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18
Q

DC means?

A

Direct Current.

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19
Q

Low Voltage Holiday detectors consist of:

  1. Portable ___ ___ electronic instrument.
  2. ___ handle with clamps to hold sponge.
  3. ___ ___ sponge (Cellulose)
  4. ___ wire.
A
  1. Portable battery powered
    electronic instrument.
  2. Non-conductive handle with clamps to hold sponge.
  3. Open Cell sponge (Cellulose)
  4. Ground wire.
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20
Q

Some low voltage holiday detectors are fixed at a 1___ ___, while others have a 2___ ___ selected.

A
  1. Specific Voltage.

2. Test Voltage Selected.
Doesn’t that mean it’s also fixed?

21
Q

Low voltage holiday detectors have a ground cable which must be connected to the 1___ ___ of a 2___ ___ for 3___ ___ contact.

A
  1. Bare Metal
  2. Conductive substrate
  3. Positive electrical
22
Q

When using LV HD’s on concrete connect directly to the 1___ ___ (aka ___). If this is not available an no other metal object within the concrete is available: make a 2___ ___ to the concrete by placing a 3___ ___ ___ on the concrete and anchoring it down with a burlap bag filled with damp sand.

Alternatively, drive a 4___ ___, ___, or ___ into the concrete. Wetting the concrete in the area will help establish 5___.

A
  1. Reinforcing steel. (aka Rebar)
  2. Ground Connection.
  3. Bare ground wire.
  4. Metal fastener, stub or nail.
  5. Continuity.
23
Q

After grounding a Low voltage holiday detector, 1___ the ___ with a solution of 2___ ___, not ___, and a 3___ ___ ___ ___. Add 4___ to 5___ of water. Wet the sponge just barely enough to avoid dripping while moving over the coating.

A
  1. Saturate the Sponge
  2. Tap Water, not distilled.
  3. Low sudsing wetting agent.
  4. 1 oz
  5. 1 gallon.
24
Q

After wetting the LV HD connect to a bare spot on the substrate with the wet sponge to verify that the instrument is 1___ ___. Repeat this procedure periodically during the test., especially when testing coatings over 2___.

A
  1. Properly Grounded.

2. Concrete.

25
Q

Excess moisture can cause erroneous indications by creating a path across the coating to pinholes previously detected, or directly to the signal return connection. This is called?

A

Telegraphing.

26
Q

Once the LV HD is grounded wipe the coated surface with the wetted sponge at a maximum rate of 1___ per second. Avoid using excess water in the sponge because the rundown could 2____ the ___ to a flaw located several feet away and give a false reading. Use a double stroke of the 3___ ___ over each area. This ensures better inspection coverage. When a holiday is found, the instrument will emit an audible tone.

A
  1. 1 foot per second.
  2. Complete the circuit.
  3. Sponge Electrode.
27
Q

LV Sponge HD. The sponge is an?

A

Electrode

28
Q

Use only approved or specified wetting agents. Mark all holidays with a non-intrusive marker such as a 1___ ___ ___. Clean the area to be repaired to ensure the wetting agent is removed before making repairs.

A
  1. White-Calcium Chalk.
29
Q

___ retained in the coating can cause erroneous indications during electrical testing.

A

Solvents.

30
Q

These types of tests are referred to as?

A

Electrical testing.

31
Q

Relevant Standards that may be consulted (depending on the specification, coating/substrate type) include:

A

AN/NZS 3894.2

ASTM D 5162-A

32
Q

Relevant Standards that may be consulted (depending on the specification, coating/substrate type) include:

A

AN/NZS 3894.2

ASTM D 5162-A

ASTM G62-A

BS 7793-2

ISO 8289 A

ISO 14654

NACE SP0188

NACE TM0384

33
Q

LV HD’s are ___ ___.

A

Factory calibrated.

34
Q

LV HD’s are usually calibrated at the factory and set at 1___ ___ (+/- 10 percent of current flow to complete the circuit triggering the audible signal that indicates a coating holiday.

A

700 Microamperes.

35
Q

The use of LV HD’s on concrete requires the detector be adjusted for a current flow of 1___ ___. This is generally achieved by removing a 2___ from the electronic circuitry.

A
  1. 500 Microameres.

2. Resister

36
Q

LV (wet sponge) HD’s may also be used to locate holidays in 1___ coatings applied to 2___ substrates. These instruments are portable and easy to operate. They are reliable on coatings up to 3___ thick, but require a slower wipe speed since the moisture has further to travel to reach the substrate.

A
  1. Non-conductive
  2. Conductive.
  3. 20 mils.
37
Q

LV (wet sponge) HD’s may also be used to locate holidays in 1___ coatings applied to 2___ substrates. These instruments are portable and easy to operate. They are reliable on coatings up to 3___ thick. They can locate holidays on thicker coatings but require a slower wipe speed since the moisture has further to travel to reach the substrate.

A
  1. Non-conductive
  2. Conductive.
  3. 20 mils.
38
Q

LV (wet sponge) HD’s may also be used to locate holidays in 1___ coatings applied to 2___ substrates. These instruments are portable and easy to operate. They are reliable on coatings up to 3___ thick. They can locate holidays on thicker coatings but require a slower wipe speed since the moisture has further to travel to reach the substrate.

A
  1. Non-conductive
  2. Conductive.
  3. 20 mils.
39
Q

The LV method is preferred by some users because it does not easily damage the coating film. However, use is limed to ___ ___.

A

Uncovered substrate.

What does this mean? Uncoated? That’s not what it’s been saying.

40
Q

Holiday detectors are not save and cannot be used in?

A

Hazardous environments.

41
Q

Common Voltages are?

A

9 v
67.5 v
90 v
120 v

42
Q

Common Voltages are?

A

9 v
67.5 v
90 v
120 v

43
Q

Given equal conditions, repeatability of results is 1___ ___ for the instruments. Variation in results stem from 2___ ___ and ___ ___.

A
  1. Very high.

2. Operator technique and wipe speed.

44
Q

Given equal conditions, repeatability of results is 1___ ___ for the instruments. Variation in results stem from 2___ ___ and ___ ___.

A
  1. Very high.

2. Operator technique and wipe speed.

45
Q

Common errors with LVHD’s are:

  1. Failure to keep the ___ in ___ with the ___.
  2. Moving the electrode ___ ___ or ___ across the surface.
  3. loss of ___ to the ___.
  4. Over or under ___ ___.
A
  1. Failure to keep the probe in contact with the substrate.
  2. Moving the electrode too fast or slow across the surface.
  3. loss of connection to the substrate.
  4. Over or under saturated sponge.
46
Q

Some LVHD equipment based errors:

  1. No fault alarm caused by low battery or ___ ___/___ ___ causing high electrical resistance.
  2. Excess ___.
A
  1. No fault alarm caused by low battery or bad lead/ground connection causing high electrical resistance.
  2. Excess moisture.
47
Q

Can LV HD’s be used on concrete?

A

Yes

48
Q

What is the max DFT recommended for proper use of LV HD’s?

A

20 mils.

49
Q

How much surficant should be added to the water.

A

1 oz per gallon.

CIP Level 1 Section 21 (2 decks)

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