PS 200 Ferroscan PS 200 Ferroscan

frizzflowerUrban and Civil

Nov 29, 2013 (4 years and 7 months ago)


Measuring Systems

PS 200 Ferroscan

PS 200 Ferroscan

Measuring Systems

Measuring Systems

Application Knowledge

Application Knowledge

Measuring Systems

Rebar is added to concrete to increase its tensile strength

Concrete is very strong in compression, but very weak in tension

Loads placed on concrete are tension which may cause the concrete

to break

Rebar can be added to concrete for added strength

Measuring Systems

Rebar placement and coverage information can be critical

Rebar Corrosion

weakening of the concrete

Fire Protection

rebar loses its strength

Rebar Verification for Load Changes

can a structure’s use
be changed?

Safe and Fast Drilling

not hitting statically relevant rebar,
less wear and tear on drills and bits

Knowledge of rebar placement and the amount of concrete coverage
can be critical to insure the integrity of the structure

Factors influencing rebar integrity:

Measuring Systems

Concrete surfaces sprayed repeatedly with salty water from
the ocean or road surfaces during winter

The salts penetrate the surface and soak into the rebar

The rebar corrodes and expands

The structure is weakened by the corroded rebar. In some
instances, the concrete surface may blow off

Rebar corrosion weakens concrete structures

Measuring Systems

Concrete surface is exposed to fire over a long period of time

The heat will penetrate the concrete

Rebar that heats up loses its strength. Almost all strength is
lost at about 932
F (500
C) and an average building fire
temperature is 1500
F (815
C). The deeper
the rebar is in the concrete, the less it will heat up

The rebar loses its strength and the structure can be damaged

Rebar loses is strength in high temperatures, such as fires

Measuring Systems

Changing loads on a structure …

Can the structure’s use be changed?

Knowing rebar placement and size can determine the load placed on it

Measuring Systems

Knowing rebar location aids safe and fast drilling

Prevent cutting of statically relevant

Increase life of drill and core bits

Reduce wear and tear on tool motors

Reduce time spent drilling

Measuring Systems


Fire protection

Change of
loads on a

Safe Drilling

General Contractors

Civil Contractors

Civil Engineers

General Contractors

Diamond Specialists

Road, Bridge and
Tunnel Contractors

Mechanical & Electrical

The Issue


Who needs the

Application / User / Scan Mode Matrix






Scan Mode

General Contractors

Civil Contractors

Civil Engineers

Measuring Systems

Detection Principle

Detection Principle

Measuring Systems



Radar waves

Magnetic field

There are 3 main types of detection tools

1. Induction

PS 200

2. Reflection


3. Inflection




Must be processed in an office

Very difficult to analyze

Very poor depth measurement

The size of the tool determines the
depth it will read

the smaller tools
don’t see very deep

Cannot work in a damp or wet

Can see everything in the

Can see very deep in the
concrete with large, push
behind equipment


the working area
has to be cleared of people

No depth measurement

Must have access to both sides of
the structure

Very slow to process image

Extremely expensive

Can see everything in the

Very clear, 2
D image

Instant, 3
D image

Can analyze the image on the

Easy operation

Can analyze large areas quickly

Very good depth accuracy

Can use on floors, walls or ceilings

Detects rebar and other ferrous
objects only

Image depth limited to 7.1” (180 mm)
depending on rebar size

Measuring Systems

The distortion creates a current around the 7 sensor
coils and produces a signal the tool can interpret

When the scanner is far away from rebar or ferrous
metal it produces a perfect magnetic field

When the scanner is placed over rebar the magnetic
field becomes distorted

The magnetic field produced by the PS 200 becomes distorted

Measuring Systems

Because the signal that is created around the sensor coils cannot determine
rebar diameter or depth, other factors also have to be considered:

Signal strength alone cannot determine rebar size


Two different sized bars can have the same signal strength


The signal strength is always strongest at the surface

Additional factors that must be examined


Start and end points of the signal







The PS 200 is programmed to calculate the depth and diameter based on
US and Canadian rebar standards

Other factors are considered in determining rebar diameter and depth






Measuring Systems

A large rebar deeper in the concrete produces the same signal as a smaller bar
near the surface

The amount of signal generated does not indicate rebar size

Two different sized boxes will make the same size shadow depending on the
distance they are away from the light source

Measuring Systems

The software uses
mathematical analysis to
determine the number and
approximate position of the

Next, it separates the
signals into individual

Last, the software
determines the bar size
and depth

The software analyzes the data to determine rebar position, depth and diameter

Location, coverage and diameter

Measuring Systems

Based on the magnetic principle of locating, determining
diameter and depth of rebar, there are other factors that
influence what the PS 200 is able to detect:

Other factors also influence what the PS 200 can detect

Rebar Spacing


Rebar that is closely spaced together

The Shading Effect

Ferrous Metal Detection


The PS 200 is designed to detect ferrous metal,
specifically rebar that meets US and Canadian rebar

Measuring Systems

Rebar Spacing can effect the PS 200’s ability to distinguish rebar

Rebar must be spaced a minimum distance apart for the PS 200 to be
able to distinguish individual bars

C = Coverage S = Spacing

The minimum rebar spacing is defined as the ratio S:C (Spacing:Coverage)
and the bars must be at least 1” in the concrete

For image and depth of rebar, the ratio is
≥ 1:1

To determine diameter, the ratio is
≥ 3:1

Using Quickscan Detection, the ratio is
≥ 2:1

Using Quickscan Recording, the ratio is ≥ 1:1

For example, to determine the image of rebar 4 in
(100 mm) in the concrete, the rebars must be at
least 4 in (100 mm) apart.

Measuring Systems

The Shading Effect

the magnetic field from the first layer of rebar
shades the second layer of rebar preventing detection of second layer.

1st Layer of

2nd Layer of


The Shading Effect can also effect the PS 200’s ability to distinguish rebar