ASCE SUE defs and Pipe and Cable Locator

Question 1

In general, when you know what type of utility you’re currently locating, should you start your search with the highest useful frequency range, or lower? Why?

Answer 1

Lowest - least bleedoff and distortion. Long-distance.

Question 2

Which types of utilities are suitable to find using Low frequency — (100Hz — 1 kHz) range?

Answer 2

Cables, insulated pipes and cable identification
Long distance
Less coupling to adjacent lines
Travels the farthest on cables, insulated pipe and cable identification.

Question 3

Which active mode method(s) are suitable when using Low frequency — (100Hz — 1 kHz) range?

Answer 3

Direct Connection

Question 4

Which types of utilities are suitable to find using Medium frequency —(8 kHz — 33 kHz) range?

Answer 4

General purpose
Cables and pipes

Moderate distance
Good all-around locating frequencies using any method of applying the signal.

Question 5

Which active mode method(s) are suitable when using Medium frequency —(8 kHz — 33 kHz) range?

Answer 5

Used by direct connection, clamp or induction (33kHZ+)

Question 6

High frequency — (65 kHz — 200 kHz) use scenarios

Answer 6

High resistance or poorly grounded
Good for jumping insulated joints
Most suited to induction
Generally shorter distance
Will couple to adjacent lines
Good for induction, Short distance, and badly grounded lines

Question 7

Commonly used frequencies for Utility locating?

Answer 7

512 Hz, 8kHz, 33 kHz, and 200 kHz.

Question 8

Mode for identifying distortion?

Answer 8

Null mode.

In Peak Mode, the horizontal antennas in the locator receiver detects the field. The signal will be strongest when centered on the field because more of it passes through the antenna.
In Null Mode, the vertical antenna detects the field. The field is not passing through the antenna when it is positioned over its center

If the field is round (no distortion), then Peak and Null modes will agree and provide the same location.

Question 9

Signal Clamp placement w.r.t. grounding point?

Answer 9

The clamp is placed around the utility and below the grounding point to ensure the signal has a signal path between near and far ground points.

Question 10

In drop the box (induction) method, which frequencies should you use, and how far away from the box should you be?

Answer 10

move at least 30 feet away from the transmitter, which must be in line with the utility when locating it using induction. They will use frequencies of 65 kHz or higher.

Question 11

A defined point on a Utility Feature or a Utility
Segment.
A Utility Feature will have at least a single __________,
whereas a Utility Segment will have a minimum of two
__________s, one on each end.

Answer 11

Anchor Point

Question 12

Deliverable

Answer 12

The sealed results from a Subsurface Utility
Engineering investigation that typically includes a Utility Report,
Utility Drawings, and other relevant Utility data for inclusion in
digital or paper formats, and/or within databases and/or threedimensional mode

Question 13

This describes which term? What is the potential quality level of said term?:

The application and interpretation of shallow-earth Geophysical Methods to infer (with or without surface markings) the existence and the approximate horizontal position
and, when possible and part of the Scope of Work, Depth of a
subsurface Utility Segment and/or Utility Feature.

_________ is not Utility Quality Level B; however,
referencing the geospatial locational accuracy of the
Designations to the Project Survey Datum and applying
professional judgment for potential alignment adjustments
that considers other relevant information in hand at that time
may lead to a horizontal Documentation of that investigated
subsurface Utility Segment or Utility Feature as Utility
Quality Level B

Answer 13

Designating

(QLB)

Question 14

The results of the act of Designating, conventionally placement of a physical marking on the ground surface of the geophysical interpretation in the field.

New Designating methods can now combine recording and
georeferencing of the geophysical signal [e.g., ground
penetrating radar (GPR) or induced electromagnetic field
plus the instruments’ positions] for subsequent data reduction
and anomaly interpretation in a controlled desktop
environment, making ground markings unnecessary.

Answer 14

Designation

Question 15

This describes which term? What is the potential quality level of said term?:

The process of exposing and verifying a Utility for
purposes of determining its function, type, position, outside
dimensions, and other observable Attributes at its exposed point.

________ is not Utility Quality Level A; however,
referencing the locational accuracy of the exposed Utility
to the Project Survey Datum and applying professional
judgment that considers other relevant information in
hand at that time can lead to the assignment of Utility
Quality Level A to the exposed portion of that Utility
Segment or Utility Feature. Measured and observed
Attributes may be used to confirm, add, or edit Attributes
of contiguous existing Utility Segments.

Answer 15

Locating

(i.e. QLA)

Question 16

Which term?:

The specialty practice of civil engineering’s Utility Engineering branch that
includes the investigation, analysis, judgment, and documentation of existing Utility networks.
______ is a type of a Utility Investigation that includes
underground networks and scoped aspects of
aboveground networks that results in the assignment of
achieved Utility Quality Levels to nonvisible Utility
Segments and Utility Features.

Answer 16

SUE

Question 17

Term?:

A reference system used by the
Project Owner and Engineer to define a specific geographic
location in a three-dimensional space.

Answer 17

Project Survey Datum

More info: The reference system is typically tied to a published datum,
that is, State Plane Coordinate Systems or the National
Spatial Reference System or to a defined project datum.
The datums, coordinates systems, and positioning
parameters that tie the reference system to the published
datum will be provided in the SUE Deliverable, such as the
vertical positioning data (e.g., orthometric height datum,
static benchmark information, or geoid model); horizontal
positioning data (e.g., coordinate system name and zone,
combined scale factor, point about which the coordinates
are scaled about, map projection, reference frame, and
ellipsoid); and units of measurements and conversions, if
any, used to convert from English to metric units. If there is
no standard datum available, a local datum is acceptable

Question 18

Term?

A privately, publicly, or cooperatively owned pipeline,
cable(s), and/or conduits, facility, or system for producing,
transmitting, or distributing communications, traffic control
cables and structures, cable television, power, electricity, light,
heat, gas, oil, crude products, water, steam, waste, stormwater, or
any other similar commodity, including any fire or police signal
system or street lighting system. The term _____ shall also mean
the ________owner/operator inclusive of any wholly owned or
controlled subsidiary

Answer 18

Utility

Question 19

Term?

A physical component of a Utility.
Examples include valves, hydrants, reducers, switches,
thrust blocks, vaults, and transformers.

Answer 19

Utility Feature.

Utility Features have a specific location and geometry.
Utility Features canbe aboveground or subsurface.
In previous versions of ASCE 38, a visible Utility Feature was called a Utility
appurtenance.

Question 20

True or False: The term “utility Investigation” is restricted to just the field activities undertake to understand and document utilities.

Answer 20

False.

Any or all of a variety of office and field
activities undertaken to understand and document the existence,
location, and Attributes of existing Utility facilities within the
project limits.
Assigning Utility Quality Levels to Utility facilities is only
possible when these activities are carried out under the
Direct Supervision of a Professional in accordance with
the requirements described in this standard.

Question 21

When performing a survey grid as part of a geophysical search where we are tracing the path of a specific utility(s), what grid spacing should we use in order to “connect the dots” such that “guesswork” segments between data points can be considered QLB?

Answer 21

To stay in QLB, we should use grid spacings less than twice the width of a sensor.

Otherwise, between the data points, it is QLD IF you have records. (without records, there is no indication of utility present and should not have a Util Quality level) In other words, grid techniques are good for search but not trace requirements unless the grid spacing is
small enough to eliminate any doubt of Utility turns or continuity
(usually dependent on Utility size and material).

Question 22

What frequency would you use to locate a relatively
shallow cast iron pipe with rubber or other nonmetallic jointing
material?

Answer 22

Very high. It might only be found using the high 480 kHz frequency.

Question 23

When locating/tracing a deep steel pipeline, what frequency might you use to:
A. Find
B: Trace

Answer 23

A deep steel pipeline may need the 8 kHz frequency to
find it and the 1 kHz frequency to trace it for any length of
distance.

Question 24

Regarding Target Material properties, what are Limitations of EM Pipe and Cable Locators (PCLs)

Answer 24

PCL devices are limited to the possible detection of continuously metallic structures or structures that can be made to act as if they are metallic.

Installation of a metal tape or “tracer wire” directly above the
Utility during construction is one way to allow a nonmetallic
Utility’s location to be inferred. There are also metallic insertion
devices for situations in which pipes or conduits, typically empty
and/or out-of-service, can be accessed. Pipe diameter, material,
number of bends and their proximity to one another, pipe
constrictions, and check-valve placement all affect capabilities.

Question 25

What is a Sonde?

Answer 25

Pipe and cable locators devices can also use sondes, or small
radio transmitters, which are inserted into an accessible pipe or
conduit. By detecting the sonde at numerous points as it is pushed
through the pipe or conduit, the user can infer the position of the
Utility. Cameras can be inserted at the front of a sonde so that a
video can be taken of the inside of the pipe or conduit. This can be
useful for condition assessment as well as location interpretation.

Question 26

What is an RFID tag?

Answer 26

Radio Frequency Identification - A type of miniature
sonde, called RFID, has been used more frequently over the
last several decades. RFID tags are installed on or near the
Utility during construction or exposure for maintenance or other
purposes. Some of these devices can be programmed to include
information about the Utility, such as ownership, type, size, and
Depth. A highly important use of RFID
is to confirm the interpretation of a Utility as a particular one.

Question 27

When considering utility depth, where do GPRs measure utility from?

Answer 27

GPR Depths indicate the top of the Utility

Question 28

When considering utility depth, where do PCLs measure utility from?

Answer 28

PCLs the middle of the Utility (or it is the location of a tracer wire),

Question 29

When considering utility depth, where do Sondes measure utility from?

Answer 29

sondes measure the bottom inside invert of the Utility.