Elcometer 207 User manual

English
Elcometer 207 • 207DL
Ultrasonic Thickness Gauge
Operating Instructions

English
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The Elcometer 207 and 207DL Ultrasonic Thickness Gauges have been tested in accordance
with EU regulations governing Electro-magnetic compliance and they meet the required
directives.
is a registered trademark of Elcometer Instruments Ltd.
All other trademarks acknowledged.
© Copyright Elcometer Instruments Ltd. 2007.
All rights reserved. No part of this document may be reproduced, transmitted, transcribed, stored (in a retrieval
system or otherwise) or translated into any language, in any form or by any means (electronic, mechanical,
magnetic, optical, manual or otherwise) without the prior written permission of Elcometer Instruments Ltd.
A copy of this Instruction Manual is available for download on our Website via www.elcometer.com/
downloads.
Doc.No. TMA-0250 Issue 04
Text with Cover No: 16524

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CONTENTS
Section Page
1 About your gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Quick-start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Getting started. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 Taking a reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6 Set-up options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7 Transferring readings to a computer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8 Using the data logger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
9 Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
10 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
11 Related equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
12 Technical specification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
13 Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
14 Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
15 Transducers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
16 Condition and preparation of surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
17 Application notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
18 Data transfer software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
19 Sound velocities of common materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

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Thank you for purchasing this Elcometer 207/207DL Precision Ultrasonic Thickness Gauge.
Welcome to Elcometer.
Elcometer are world leaders in the design, manufacture and supply of coatings inspection equipment. Our
products cover all aspects of coating inspection, from development through application to post application
inspection.
The Elcometer 207/207DL Precision Ultrasonic Thickness Gauge are world beating products. With the
purchase of this gauge you now have access to the worldwide service and support network of Elcometer.
For more information visit our website at www.elcometer.com.
1 ABOUT YOUR GAUGE
The Elcometer 207/207DL Precision Ultrasonic Thickness Gauges are handheld gauges for fast and
accurate measurement of the thickness of thin materials.
Your gauge is capable of measuring the thickness of various materials with accuracy as high as ± 0.002 mm
(± 0.0001"). The principal advantage of ultrasonic measurement over traditional methods is that ultrasonic
measurements can be performed with access to only one side of the material being measured.
Your gauge is also capable of measuring the thickness of plastics.
There are two versions of the gauge:
• The Elcometer 207 is the basic model.
• The Elcometer 207DL model includes all the features of the Elcometer 207 model plus a data-logging
(memory) facility which allows readings to be stored in batches before being downloaded to a
computer.
This manual describes the operation of both models - Elcometer 207 and 207DL.

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1.1 WHAT THIS BOX CONTAINS
• Elcometer 207 or 207DL Gauge
• Bottle of couplant
• Battery, 2 x
• Carrying case
• Operating instructions
• CD with data transfer and data collection software (DL version only)
• Data transfer cable
• 15MHz, 6mm (1/4”) microdot right angle transducer
Your gauge is packed in a cardboard and foam package. Please ensure that this packaging is disposed of
in an environmentally sensitive manner. Please consult your Local Environmental Authority for further
guidance.
To maximise the benefits of your new Elcometer Ultrasonic Thickness Gauge, please take some
time to read these Operating Instructions. Do not hesitate to contact Elcometer or your Elcometer
supplier if you have any questions.
1.2 FEATURES OF THE GAUGE
E
CHO - TO - ECHO MODE : Allows measurement of coated materials without having to remove the coating.
I
NTERFACE - TO - ECHO MODE : The gauge switches to this mode automatically when measuring thicker
materials and plastic.
P
LAS MODE : For measuring the thickness of plastics.

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S
CAN MODE : Identifies the minimum thickness over a large area while moving the transducer over the
surface. While the transducer is in contact with the material being measured the smallest value is held in
memory and displayed when scanning is complete.
A
LARM : Allows the user to set a target so that an audible and visual alarm operates when taking
measurements. If the measurement falls below a pre-set nominal (target) value a red LED will light and the
beeper sounds. A green LED will light to indicate an acceptable thickness.
D
ATA OUTPUT : Allows the user to send data direct to a printer or PC.
D
ATA - LOGGING (207DL VERSION ONLY ): Memory capacity of up to 1000 readings. Readings are stored in up
to 10 batches each containing up to 100 readings. Batches may be transferred to a PC using supplied
software.
2 QUICK-START
To quickly configure the gauge and start taking readings:
1. Fit batteries: . . . . . . . . . . . . . . . see page 5
2. Fit transducer:. . . . . . . . . . . . . . see page 6
3. Switch on: . . . . . . . . . . . . . . . . . see page 7/9
4. Try taking a reading: . . . . . . . . . see page 13
5. Adjust calibration: . . . . . . . . . . . see page 15
The gauge is now configured and ready to use.

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3 GETTING STARTED
3.1 FITTING BATTERIES
Your gauge may be used with dry cell batteries or rechargeable batteries.
2 x LR6 (AA) alkaline batteries are supplied in the kit.
To fit or replace batteries:
1. Locate battery compartment cover at top of gauge.
2. Unscrew battery compartment cover.
3. Referring to battery polarity instructions on rear of gauge, insert
batteries into gauge ensuring correct polarity.
4. Replace battery compartment cover.
Remove the batteries from the gauge if it is to remain unused for a long
period of time. This will prevent damage to the gauge in the event of
malfunction of the batteries.
When the battery voltage is low the entire display will start to flash. When
this occurs the batteries should be replaced.
Note: Alkaline batteries must be disposed of carefully to avoid
environmental contamination. Please consult your local environmental
authority for information on disposal in your region.
Do not dispose of any batteries in fire.
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3.2 THE TRANSDUCER
The transducer transmits and receives the ultrasonic energy or sound waves that the
gauge uses to determine the thickness of the material being measured. The
transducer is connected to the gauge via a cable and a coaxial connector (Microdot
connector).
The transducer must be used correctly in order for the gauge to produce accurate,
reliable measurements. The Elcometer 207 and the Elcometer 207DL operate only
with the 15 MHz precision ultrasonic transducer.
The diagram shows the side view of the 15 MHz, single-element delay line
transducer. The delay line is attached to the transducer with a retainer ring. A drop of
couplant is applied between the delay line and the transducer body to allow the
energy to be coupled in to the delay line. The transducer body has a single crystal element that generates
the ultrasonic energy and this energy is coupled to the material to be measured. The energy passes from
the transducer in to the material. It is reflected from the far wall of the material and coupled back in to the
transducer. The area directly beneath the delay line is that which is measured.
Your gauge is supplied with two replaceable delay lines, 6.35 mm (1/4") and 12.7 mm (1/2"). The 12.7 mm
(1/2") is suitable for most applications and measures steel up to 25 mm. Generally, it should be used to
measure thicker materials. It will also dampen the signal of noisy materials, providing better accuracy.
The 6.35 mm (1/4") delay line provides more signal strength and may allow you to measure tough-to-
penetrate materials.
To change the delay line, unscrew the end of the transducer and apply couplant to the connecting end of
the delay line before screwing together.

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3.3 THE KEYPAD
ELCOMETER 207
Key Functions For more information see
Press to switch the gauge on or off.
When switching off, the gauge retains all of its settings.
If the gauge is idle for 5 minutes, it will switch itself off.
Press to switch SCAN mode on or off. “Scan mode” on page 20.
Press to adjust calibration. “Calibration” on page 15.
Press to change units (metric/imperial)
a) Increases values on the display (press and hold to change values quickly).
b) Switches between measurement modes (echo-echo, interface-echo or
auto).
a) Decreases values on the display (press and hold to change values
quickly).
b) Switches the display backlight between three settings; on, off and auto. “Backlight” on page 24.
c) Press and hold during gauge switch on to toggle LOC mode on/off “Measurement mode” on
page 18
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a) Press and hold during gauge switch on to toggle the audible beeper on or
off.
b) Press to toggle the alarm on or off, and to adjust the nominal thickness
value. “Alarm” on page 22.
Press to toggle the DIFFERENTIAL mode on or off, and to adjust the nominal
thickness value. “Differential Mode” on page 21.
Press to send the displayed thickness measurement to an external storage
device via the RS232 port. “Transferring data” on page 27.
Key Functions For more information see
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ELCOMETER 207DL
Key Functions For more information see
Press to switch the gauge on or off.
When switching off, the gauge retains all of its settings.
If the gauge is idle for 5 minutes, it will switch itself off.
Press to adjust the features and settings of the gauge (alarm, scan, mode,
units, backlight, and beeper). .
Press to adjust calibration. “Calibration” on page 15.
Press to change units (metric/imperial)
a) Increases values on the display (press and hold to change values quickly).
b) When MODE key has been pressed, scrolls through the various features
and settings of the gauge.
c) When MEM key has been pressed, scrolls through the various files,
memory locations, and functions of the data logger.
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a) Decreases values on the display (press and hold to change values
quickly).
b) When MODE key has been pressed, scrolls through the various features
and settings of the gauge.
c) When MEM key has been pressed, scrolls through the various files,
memory locations, and functions of the data logger.
Press to switch data logging (memory) on/off. “Using the data logger” on
page 27
Press when data logger is switched on to clear the contents of an entire
batch, or an individual memory location.
The CLR key is also used to send an obstruct message (ObSt) to an
individual memory location. The ObSt symbol would indicate that the user
was unable to take a reading at a particular location.
“Using the data logger” on
page 27.
a) Press to send the displayed thickness measurement to an internal
memory location or an external storage device via the RS232 port. “Transferring data” on page 27.
b) Press to select data logging functions. “Using the data logger” on
page 27
Key Functions For more information see
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3.4 THE DISPLAY
Stability indicator
Refer to “Read display” on page 14 and “Transducers” on page 37 for information on how to achieve a
stable measurement.
One bar - no readings are being taken
Less than 5 bars - reading is unstable and may be inaccurate
More than 5 bars - reading is stable
INMM/ s µ
Stability indicator (see below) Units (IN, MM, IN/µs, MM/s)
Thickness value/Menu items

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3.5 FRONT PANEL LIGHTS
Green light illuminates when:
• The alarm mode is active, and
• the measured thickness is greater than the alarm value.
Red light illuminates when:
• The alarm mode is active, and
• the measured thickness is less than the alarm value.

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4 TAKING A READING
Disclaimer: Inherent in ultrasonic thickness measurement is the possibility that the instrument will use the
second echo rather than the first echo from the back surface of the material being measured while in
standard pulse-echo mode. This may result in a thickness reading which is TWICE what it should be.
The responsibility for proper use of the instrument and recognition of these types of phenomenon rests
solely with the user of the instrument.
4.1 BEFORE YOU START
•Calibrate the gauge. . . . . . . . . . . . . . See “Calibration” on page 15.
•Prepare the surface. . . . . . . . . . . . . . See “Condition and preparation of surfaces” on page 39.
1. Apply couplant
For the gauge to work correctly there must be no air gaps between the transducer and the surface of
the material to be measured. This is achieved using a material called a couplant.
Before the transducer is placed on the surface, put a small amount of the couplant supplied with the
gauge on the surface of the material. Typically a single drop is sufficient.
2. Place transducer onto surface of material to be measured
Press the transducer with the delay line into the couplant. Moderate pressure on the top of the
transducer using the thumb or index finger is sufficient; it is only necessary to keep the transducer
stationary and the delay line surface seated flat against the surface of the material.

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3. Read display
If six or seven bars of the stability indicator are showing, the display will be reading the correct
thickness of the material directly beneath the transducer.
If the stability indicator has fewer than five bars showing, or the numbers on the display seem erratic,
check to make sure that there is an adequate film of couplant beneath the transducer, and that the
transducer is seated flat against the material. If the condition persists, it may be necessary to select a
different transducer (size or frequency) for the material being measured.
The gauge will perform four measurements every second when the transducer is in contact with the
surface of the material. The display is updated as each reading is taken.
4. Remove transducer from surface
The display will show the last measurement made.
Note: Occasionally, a small film of couplant will be drawn out between the transducer and the surface as
the transducer is removed. When this happens, the gauge may perform a measurement through this
couplant film, resulting in a measurement that is larger or smaller than it should be. This phenomenon is
obvious when one thickness value is observed while the transducer is in place, and another value is
observed after the transducer is removed. If this happens, take the reading again using less couplant.

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5 CALIBRATION
In order for the gauge to make accurate measurements, it must be set to the correct sound-velocity for the
material being measured.
Different types of material have different sound-velocities. For example, the velocity of sound through steel
is 5918 m/s (about 0.233 in/µs) and the velocity of sound through aluminium is 6350 m/s (about 0.248 in/
µs).
If the gauge is not set to the correct sound-velocity, all of the measurements the gauge makes will be
erroneous by some fixed percentage.
There are three methods of calibrating your gauge:
K
NOWN THICKNESS CALIBRATION : This is the simplest and most commonly used calibration procedure -
optimising linearity over large ranges. One-point calibration is carried out using a known thickness.
K
NOWN VELOCITY CALIBRATION : The sound-velocity of the material being measured is entered directly into
the gauge.
Note: Known thickness calibration must be performed on material with the paint or coating removed. Failure
to remove the paint or coating prior to calibration will result in a multi-material velocity calculation that may
be different from the actual material velocity intended to be measured.

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5.1 KNOWN THICKNESS CALIBRATION
This procedure requires a sample piece of the material to be measured, the exact thickness of which is
known, e.g. from having been measured by some other means.
1. Switch on the gauge.
2. Apply couplant to the sample piece.
3. Press the transducer against the sample piece, making sure that the transducer is flat against the
surface of the sample. The display should show some (probably incorrect) thickness value, and nearly
all the bars of the stability indicator should be illuminated.
4. Having achieved a stable reading, remove the transducer.
If the displayed thickness changes from the value shown while the transducer was coupled, repeat
step 3 and 4.
5. Press the CAL key. The MM (or IN) symbol should begin flashing.
6. Use the UP and DOWN arrow keys to adjust the displayed thickness up or down, until it matches the
known thickness of the sample piece.
7. Press the CAL key again. The M/s (or IN/µs) symbols should begin flashing. The gauge is now
displaying the sound-velocity value it has calculated.
8. Press the CAL key once more to exit the calibration mode.
The gauge is now ready to perform measurements.

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5.2 KNOWN VELOCITY CALIBRATION
This procedure requires that the operator knows the sound-velocity of the material to be measured. A table
of common materials and their sound-velocities can be found in “Sound velocities of common materials” on
page 43.
1. Press ON/OFF key to switch on the gauge.
2. Press the CAL key to enter calibration mode. If the MM (or IN) symbol is flashing, press the CAL key
again, so that the M/s (or IN/µs) symbols are flashing.
3. Use the UP and DOWN arrow keys to adjust the displayed velocity up or down, until it matches the
sound-velocity of the material to be measured.
4. Press the CAL key once more to exit the calibration mode.
The gauge is now ready to perform measurements.
Note: At any time during the gauge calibration procedure (IN, MM, IN/µs, or M/s flashing in the display),
pressing the SCAN key (207) or CLR key (207DL) will restore the gauge to the factory default sound-velocity
for steel, 5918 m/s (0.233 in/µs).
To achieve the most accurate measurements possible, it is generally advisable to calibrate the gauge to a
sample piece of known thickness. Material composition (and thus, its sound-velocity) sometimes varies from
batch to batch and from manufacturer to manufacturer. Calibration to a sample of known thickness will
ensure that the gauge is set as closely as possible to the sound-velocity of the material to be measured.

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6 SET-UP OPTIONS
6.1 MEASUREMENT MODE
The gauge has three measurement modes; echo-echo, interface-echo and automatic.
E
CHO - ECHO : The gauge has the ability to read thin metals from 0.15 mm to 10.14 mm (0.006" to 0.399").
The echo-echo mode also allows the user to measure the thickness of metals that have been previously
coated or painted on the surface. This enables the user to determine the thickness of the metal without
having to remove the paint.
I
NTERFACE - ECHO : The gauge has the ability to read thicker metals from 1.65 mm to 25.4 mm (0.065" to 1.0"),
plastics and other difficult materials.
A
UTOMATIC : In Automatic, the gauge will automatically switch between modes according to the different
materials being measured.
P
LAS : Plas mode can be used to measure thin plastics using a special graphite tip - see “Spares” on
page 35.
The automatic (Auto) mode will generally be the mode of choice for the majority of common applications
with the following exceptions:
• The gauge should be set to echo-echo mode when through-coating measurements are required.
• The gauge should be set to interface-echo when plastics above 1.52 mm (0.060") are being
measured.