The different means for monitoring cracks and for measuring
crack openings
There are currently several types of crack-opening measuring
equipment for buildings which provide varying degrees of precision
and of ease of use.
Devices for measuring cracks that are precise to the hundredth
such as the ball deformeter, the GINGER CEBTP gauge, the Datalogger
(which records the data), and less precise devices such as
the crack test (fissurotest), the graduated ruler, the Vinchon
crack-measuring device, or the eyepiece micrometer.
To help you select the device adapted to crack monitoring
based on the importance of the building (art structures, pavilions,
historical monuments, residential or office building, etc.),
these devices are detailed here below.
The crack test (fissurotest):
Measure crack openings
with the GINGER CEBTP Fissurotest crack test |
This device is a transparent graduated ruler. The operator
places the crack test ruler (fissurotest) on the crack,
selecting the width of the line that corresponds to
the crack opening, using the separating power of his
eyes.
Highly practical as it can be carried in a pocket,
the Fissurotest crack measurer
is, however, an estimating tool.
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The micrometric eyepiece:
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Like the crack test (Fissurotest), this device is used
for measuring crack openings in millimetres.
Designed as a portable microscope, its internal optic
is equipped with a rotating ruler that is placed perpendicular
to the crack.
More precise than the crack test (Fissurotest), the
micrometric eyepiece measures crack openings with a
hundredth of a millimetre resolution. It can be equipped
with an internal light to make reading easier.
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Micrometric eyepiece with internal graduated
ruler for measuring cracks. |
The ball deformeter:
Measuring crack development with the ball deformeter |
The ball deformeter is a device for high-precision
crack monitoring, as its resolution is the micron.
Two balls mounted on a support are placed either side
of the crack.
The operator places the deformeter on the two balls
then measures the space between these two balls. A precision
comparator mounted on the deformeter is used for this
measurement.
Before each series of measurements, the operator resets
the device to zero on an Invar rod using two balls whose
spacing provides high dimensional stability.
The ball deformeter
may also be placed on sealed contact plates for long-term
measurements.
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The GINGER CEBTP Gauge:
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The GINGER CEBTP Gauge is a new product patented by
GINGER CEBTP which offers an excellent solution between
the graduated ruler and the ball deformeter.
The GINGER
CEBTP Gauge is made of two supports placed either
side of the crack, and a digital measuring device with
a 1/100 mm resolution. The supports may be glued or
screwed on either side of the crack for measuring.
The perfect tool for experts who wish to have a quick,
yet precise and cost-effective crack monitoring measurement.
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The GINGER CEBTP Gauge for monitoring crack
development for expertise |
The sliding ruler gauge:
Using a sliding ruler to monitor crack development |
This device offers a cost-effective, though not very
precise way of monitoring crack development. The most
common models offer a 1/10 mm resolution.
This device is comprised of two plastic graduated rulers
which slide against each other. Reading is identical
to that of a calliper gauge.
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The Vinchon crack-measuring device:
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Mechanical equipment for 3D crack development measurements
using a calliper gauge. It provides 1/10 mm precision.
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3D crack development measurement with the Vinchon crack-measuring
device |
The movement sensor:
Measuring crack development with the potentiometric sensor |
If crack monitoring requires recordings, it is advisable
to choose a potentiometric movement sensor connected
to a data acquisition centre.
This centre is programmed to periodically read and
memorize the crack opening. An alarm system initiating
an emergency phone call may be set up if the threshold
is exceeded.
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The recorder datalogger:
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Certain types of crack-monitoring equipment offer the
possibility to record the data at individual sensor
level. The sensor may be outside the Datalogger or integrated
into the recording box.
It may be possible to connect several crack-measuring
sensors to a single datalogger.
The operator intervenes periodically to read the internal
memory for processing and to empty it.
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Monitoring crack opening with several sensors and a datalogger |
You can obtain a complete set of documents about these new
equipments quickly by simply placing a request at :
M. Frédéric BOURDET
By Email
f.bourdet@gingergroupe.com
By Télécopie : +33 1 30 85 23 79
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By courrier :
GINGER CEBTP
Service Pôle Systèmes
12 Avenue Gay Lussac
ZA La Clef St Pierre
78990 ELANCOURT
France
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| The texts in the present document only
have an information purpose, and neither their author
nor CEBTP are committed by them. |
The texts, schemes and photographs represented
in the present pages are an exclusive property of CEBTP
and they cannot be reproduced under any form without a
previous written authorization of CEBTP |
Copyright ©, 2009,
CEBTP All rights reserved
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