Elcometer CG30, CG50DL, CG50 Operating Instructions Manual

Download

Model CG30

Model CG50, CG50DL

Corrosion Gauge

Operating Instructions

This product meets the Electromagnetic Compatibility Directive.

The product is Class A, Group 1 ISM equipment according to CISPR 11. Group 1 ISM product: A product in which there is intentionally generated and/or used conductively coupled radio-frequency energy which is necessary for the internal functioning of the equipment itself. Class A product are s uitable for use in all e stablishment s other than domestic and t hose directl y connected t o a low voltage power supply network which supplies buildings used for domestic purposes.

These operating instructions are available for download on our website www.elcometerndt.com. The following tradema rk is a registe red trademark o f Elcometer Limite d, Edge Lane, Ma nchester, M43 6BU. United

Kingdom:

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 Limited.

.Doc.No. TMA-0497 Issue 01

Text with Cover No: 23195

Contents

1 About your gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 The keypad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3 Getting started. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4 The display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

5 Setting up the gauge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

6 Taking a reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

7 Measurement options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

8 Measurement - Recording your Readings (CG50DL only) . . . . . . . . . . . . . . . . . . . . . . 15

9 Transferring readings to a computer - CG50/CG50DL only . . . . . . . . . . . . . . . . . . . . . 17

10 Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

11 Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

12 Technical specification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

13 Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

14 Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

15 Transducers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

16 Condition and preparation of surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

17 Application notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

18 Sound velocities of common materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Thank you for purchasing this Elcometer NDT product. Welcome to Elcometer NDT. The Model CG30, CG50 and CG50DL Ultrasonic Thickness Gauges are world beating products.

With the purchase of this gauge you now have access to the worldwide service and support network of Elcometer NDT. For more information visit our website at www.elcometerndt.com.

1 ABOUT YOUR GAUGE

The Model CG30, CG50 and CG50DL Ultrasonic Thickness Gauges are handheld gauges for fast and accurate measurement of material thickness.

Your gauge is capable of measuring the thickness of various materials with accuracy as high as ± 0.1 mm (± 0.004"). 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.

There are three versions of the gauge:

• The Model CG30 is the basic model.

• The Model CG50 includes all features of the CG30 plus differential mode, an alarm and data output.

• The Model CG50DL model includes all the features of the Model CG50 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 all three models - CG30, CG50 and CG50DL.

1.1 STANDARDS

The Models CG30, CG50 and CG50DL can be used in accordance with the following International Standards ASTM E 797, EN 14127 & EN 15317.

1.2 WHAT THIS BOX CONTAINS

Model CG30, CG50 or CG50DL Gauge, Bottle of couplant, Battery, (2 x), Carrying case, Test certificate, Operating instructions, CD with data transfer and data collection software - CG50DL only, RS232 and USB to Serial converter CG50DL only.

Note: The box does not include a transducer; these must be ordered separately. To order a transducer, contact Elcometer NDT or your local Elcometer NDT supplier.

To maximise the benefits of your new Elco meter NDT Ultrasonic Thickness Gauge, please take some time to read these Operating Instructions. Do no t hesitate to contact Elcometer NDT or your Elcometer NDT supplier if you have any q uestions.

1.3 PACKAGING

Your gauge is packed inside its carrying case within a cardboard box. Please ensure that this packaging is disposed of in an environmentally sensitive manner. Please consult your Local Environmental Authority for further guidance.

Model CG30 Model CG50

SCAN

PRB

CAL

CORROSION GAUGE

Figure 1. Models CG30 - CG50 - CG50DL

Model CG50DL

MODE

SEND

CAL

PRB

MEM

CLR

2 THE KEYPAD

MODEL CG30 (6 BUTTONS) AND CG50 (9 BUTTONS)

PRB

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 zero the gauge. See “Transducer - Zeroing” on page8.

Press to adjust calibration. See “Calibration” on page 9.

Press to change units (metric/imperial)

a) Increases values on the display (press and hold to change values quickly).

b) Switches SCAN measurement on and off. See “Scan mode” on page 12.

a) Decreases values on the display (press and hold to change values quickly).

b) Switches the display backlight between three setti ngs; on, of f and auto. See “Backli ght” on page 15.

a) Press and hold when switching the gauge on to switch the audible beeper on or off. b) Press to toggle the alarm on or off, and to adjust the nominal thickness value. See

“Alarm - CG50 and CG50DL only” on page 13. Press to toggle the DIFFERENTIAL mode on or off, and to adjust the nominal thickness

value. See “Differential Mode - CG50 and CG50DL only” on page 13.

Press to send the displayed thickness measurement to a n e xternal stora ge d evice via the RS232 port. See “Transferring readings to a computer - CG50/CG50DL only” on page 17.

CG30 CG50

CG50

MODEL CG50DL

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 zero the gauge.

PRB

See “Transducer - Zeroing” on page8.

Press to adjust calibration. See “Calibration” on page 9.

Press to adjust the features and settings of the gauge (alarm, sca n, units, backlight, and beeper).

MODE

MEM

CLR

SEND

a) Increases values on the display (press and hold to change values quickly).

b) Scrolls up through features and settings of the gauge and through files, memory locations, and functions of the data logger.

a) Decreases values on the display (press and hold to change values quickly).

b) Scrolls down through features and settings of the gauge and throug h files, memor y locations, and functions of the data logger.

Press to switch on/off data logging (memory). See “Measurement - Recording your Readings (CG50DL only)” on page 15.

Press when data logger is switched on to clear the content s 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 locat ion. The ObSt symbol would indicat e that the user was unable to take a reading at a particul ar location. See “Measurement - Recording your Readings (CG50DL only)” on page 15.

Press to send the displayed thickness measurement to an internal memory location or an external storage device via the RS232 port. See “Data T r ansfer Software” on page 17. The SEND key is also used to select data logging functions in the Model CG50DL.

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 (Figure 2) 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.

Note: 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.

Battery compartment cover

Elcometer 206

Elcometer 208

Ultrasonic Thickness Gauge

ALRM

DUAL

DIFF

MULTI

SCAN

SEND

CAL

PRB

OFF

Figure 2. Fitting batteries

3.2 CHOOSING THE TRANSDUCER

When you purchased your gauge you should have also purchased a suitable transducer for your application. If you have not yet done so, refer to “Transducers” on page 20 , which will help you

identify the correct transducer type. Alternatively contact Elcometer NDT, your local Elcometer NDT supplier or visit www.elcometerndt.com.

3.3 FITTING THE TRANSDUCER

The transducer transmits (see Figure 3) and receives ultrasonic sound waves that the gauge uses to calculate the thickness of the material being measured.

The transducer connects to the gauge via the attached cable, and two coaxial connectors. When using transducers manufactured by Elcometer NDT, the orientation of the dual coaxial connectors is not critical; either plug may be fitted to either socket.

The transducer must be used correctly in order for the gauge to produce accurate, reliable measurements.

Figure 4 shows the two semicircles of the wearface and the barrier separating them. One of the semicircles transmits ultrasonic sound into the material being measured, and the other semicircle receives the sound echoes back into the transducer. When the transducer is placed against the material being measured, it is the area directly beneath the centre of the wearface that is being measured.

Figure 3. Typical transducer

Wearface

Figure 4. Transducer - bottom view

3.4 SWITCHING ON/OFF

To switch on or off, press the on/off key The gauge will switch off automatically after 5 minutes of inactivity.

4 THE DISPLAY

Stability indicator (see below)

INMM/ s

Thickness value/

Menu items

Stability indicator

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

Refer to “Read display” on page 12 and “Transducers” on page 20 for information on how to achieve a stable measurement.

Units (IN, MM IN/µs, MM/s)

4.1 FRONT PANEL LIGHTS (CG50 & CG50DL ONLY)

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.

5 SETTING UP THE GAUGE

5.1 TRANSDUCER - ZEROING

Setting the zero point for the transducer is important for the same reason that setting the zero on a mechanical micrometer is important. If the zero point of the transducer is not set correctly, all of the measurements the gauge makes will be in error by some fixed number. When the zero point of the transducer is set, this fixed error value is measured and automatically corrected for in all subsequent measurements. Though the gauge will remember the last zero point, it is generally a good idea to set the zero point whenever the gauge is switched on, as well as any time a different transducer is used. This will ensure that the zero point of the instrument is always correct. The zero probe routine must be done prior to calibration.

To set the zero point:

1. Plug the transducer into the gauge ensuring that the connectors are fully engaged. Check that the wearface of the transducer is clean and free of any debris.

2. Switch on the gauge.

3. The battery compartment cover on the top end of the gauge acts as a metal ‘probe-disc’. Apply a single droplet of ultrasonic couplant to the top of this disc.

4. Press the transducer against the probe-disc, making sure that the transducer is flat against the surface (Figure 5). The display should show some thickness value, and nearly all the bars of the stability indicator should be illuminated.

Elcometer 206

Elcometer 208

Figure 5. Transducer pressed against probe-disc

5. While the transducer is firmly coupled to the probe-disc, press the PRB-0 key on the keypad. The gauge will display ‘Prb0’ while it is calculating the zero point.

6. Remove the transducer from the probe-disc.

When setting the zero point, the gauge will always use the sound-velocity value of the built-in probe-disc, even if some other velocity value has been entered for making measurements.

Although the gauge will remember the last zero point, it is generally a good idea to set the zero point whenever the gauge is switched on, as well as any time a different transducer is used. This will ensure that the zero point of the instrument is always correct.

5.2 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: One-point 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. Two-point CALIBRATION: This allows for greater accuracy over small ranges. Two-point

calibration is carried out using two known thicknesses. Known velocity CALIBRATION: The sound-velocity of the material being measured is entered

directly into the gauge.

Note: One-point and two-point calibrations must be performed on material with the paint or coating removed. Failure to remove the paint or coating prior to calibra tion will result in a multi-material velocity calculation that may be different from the actual material velocity intended to be measured.

5.2.1 One-point 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. Set the zero point of the gauge - see “Transducer - Zeroing” on page 8.

3. Apply couplant to the sample piece.

4. 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.

5. 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.

6. Press the CAL key. The MM (or IN) symbol should begin flashing.

7. 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.

8. 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.

9. Press the CAL key once more to exit the calibration mode.

The gauge is now ready to perform measurements.

5.2.2 Two-point calibration

This procedure requires that the operator has two known thickness points on the test piece that are representative of the range to be measured.

1. Set the zero point of the gauge - see “Transducer - Zeroing” on page 8.

2. Apply couplant to the sample piece.

3. Press the transducer against the sample piece, at the first calibration point, 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 steps 3 and 4.

5. Press the CAL key. The IN (or MM) symbol should begin flashing.

6. Use the UP and DOWN arrow keys to adjust the displayed thickness up or down, until it matches the thickness of the sample piece.

7. Press the PRB-0 key. The display will flash 1OF2.

8. Repeat steps 3 to 6 on the second calibration point.

9. 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.

10. Press the CAL key once more to exit the calibration mode.

The gauge is now ready to perform measurements within this range.

5.2.3 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 24.

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 PRB-0 key 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 t o calibrate the gauge to a sample piece of known thickness. Material compositio n (and thus, its sound-velocity) sometimes varies from lot to lot 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.

6 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.

6.1 BEFORE YOU START

• Set the zero point of the gauge. See “Transducer - Zeroing” on page 8.

• Calibrate the gauge. See “Calibration” on page 9.

• Prepare the surface. See “Condition and preparation of surfaces” on page 22.

6.2 PROCEDURE

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 wearface 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 wearface seated flat against the surface of the material.

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 nu mbers 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 t he 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 readin g aga in using less couplant.

7 MEASUREMENT OPTIONS

7.1 SCAN MODE

Although your gauge excels at making single point measurement, it is sometimes desirable to examine a larger area, searching for the thinnest point. The gauge includes a feature called Scan Mode which allows it to undertake that function.

The mode increases the overall repetition rate from 4 readings per second to 8 readings a second. This feature enables you to make scanned passes over an arbitrary length of test material while still

maintaining a reasonable representation of th ickness over the scanned area/region. This feature can be used in conjuction with the alarm limit feature.

To switch scan mode on/off:

Model CG30/CG50

1. Swi tch on the gauge.

2. Press UP/SCAN key to toggle the status of the Scan mode. The gauge will display SCAn

OFF or SCAn

On depending on which mode the gauge is

in.

3. Repeat step 2 to switch scan mode on or off.

1. Switch on the gauge.

2. Press MODE key to activate features and settings.

3. Press UP and DOWN arrow keys to scroll to SCAn symbol. The gauge will display SCAn OFF or SCAn

On depending on which mode the gauge is

in.

4. Press SEND key to switch scan mode on or off.

5. Press MODE key when finished.

Model CG50DL

7.2 DIFFERENTIAL MODE - CG50 AND CG50DL ONLY

Your gauge includes Differential Mode which allows it to display the positive or negative difference from an entered nominal value.

To switch differential mode on/off and enter the value:

Model CG50 Model CG50DL

1. Switch on the gauge.

2. Press the dIFF key. The gauge will display dIFF OFF or dIFF followed by a thickness value and flashing MM (or IN), depending on which mode the gauge is in.

3. Repeat step 2 to switch differential mode on or off.

4. Assuming dIFF value flashing MM is displayed, use the UP and DOWN arrow keys to scroll to the desired nominal thickness value.

5. Press the dIFF key once again to select the nominal value entered.

7.3 ALARM - CG50 AND CG50DL ONLY

The Alarm feature of the Models CG50 and CG50DL allows the user to set an audible and visual alarm when taking measurements.

If the alarm is switched on, the green light on the front panel of the gauge is illuminated. If the measurement falls below the value set by the user, a red light shows on the front panel of the gauge and the beeper is sounded (if it is switched on).

Use of the red light and beeper improves the speed and efficiency of the inspection process by eliminating constant viewing of the reading displayed.

1. Switch on the gauge.

2. Press MODE key to activate features and settings.

3. Press UP and DOWN arrow keys to scroll to dIFF symbol. The gauge will display dIFF OFF or dIFF followed by a thickness value and flashing MM (or IN), depending on which mode the gauge is in.

4. Press SEND key to switch differential mode on or off.

5. Assuming dIFF value flashing MM is displayed, use the UP and DOWN arrow keys to scroll to the desired nominal thickness value.

6. Press SEND key to select the desired nominal value and return to mode menu.

7. Press MODE key when finished.

To switch beeper on/off

Model CG50 Model CG50DL

1. While the gauge is off, press and hold down ALRM key.

2. Switch on the gauge.

3. Release ALRM key. The gauge will display bEEP OFF or bEEP On depending on whether the beeper is on or off.

4. Repeat steps 1 to 3 to toggle between

bEEP ON and bEEP OFF.

To set alarm value and switch alarm on:

Model CG50 Model CG50DL

1. Switch on the gauge.

2. Press ALRM key to toggle the status of the alarm until the gauge displays:

ALAr followed by a thickness value and flashing MM (or IN) symbol.

3. Press UP and DOWN arrow keys to adjust thickness value.

4. Press ALRM key when correct value is displayed.

1. Switch on the gauge.

2. Press MODE key to activate features and settings.

3. Press UP or DOWN arrow keys to scroll to bEEP. The gauge will display bEEP OFF or bEEP On depending on whether the beeper is on or off.

4. Press SEND key to toggle the status of the beeper on/off.

5. Press MODE key when finished.

1. Switch on the gauge.

2. Press MODE key to activate features and settings.

3. Press UP or DOWN arrow keys to scroll to

ALAr. The gauge will display: ALAr OFF

4. Press SEND key. The gauge will display: A thickness value and flashing MM (or IN)

mbol.

5. Press UP and DOWN arrow keys to adjust thickness value.

6. Press SEND key when correct value is displayed.

7. Press MODE key.

The alarm value is now set and the alarm is switched on.

To switch alarm off Repeat the steps above, but select ALAr OFF.

7.4 BACKLIGHT

The gauge display includes a backlight. The backlight can be set to one of three modes on/off/auto.

• ON - backlight is on

• OFF - backlight is off

• AUTO - backlight automatically illuminates while the gauge is making a measurement and switches off after several seconds (to conserve battery life).

To set backlight mode

Model CG30/CG50 Model CG50DL

1. Switch on the gauge.

2. Press DOWN key to toggle the status of the backlight. The gauge will display OFF, On or AutO, depending on backlight setting.

3. Repeat step 2 until the correct setting is displayed.

1. Switch on the gauge

2. Press MODE key to activate features and settings.

3. Press UP and DOWN arrow keys to scroll to the LItE symbol. The gauge will display LItE OFF, LItE On or LItE AutO, depending on backlight setting.

4. Press SEND key until the correct setting is displayed.

5. Press MODE key.

8 MEASUREMENT - RECORDING YOUR READINGS (CG50DL ONLY)

The Model CG50DL is equipped with a data logging feature. This is a valuable reporting gauge for inspection purposes. It increases efficiency by reducing the time it takes to manually record the measurements during the inspection process. The gauge can then be connected to a computer or serial printer to save and print the results of the inspection.

The gauge has a memory capacity of 1000 readings. Measurements are stored in up to 10 batches (files), each consisting of up to 100 readings (memory locations).

8.1 SETTING-UP THE DATA LOGGER

1. Switch on the gauge.

2. Press MEM key to activate the data logger. The display will flash FILE F-01 (or the last batch used). There are 10 batches, numbered F-01

to F-10.

3. Press the SEND key to enter batch setup. The cur rent batch will be displayed (F-01, F-03, etc.)

4. Press the UP / DOWN arrow keys to scroll to the batch (1-10) that will be used.

5. Press the SEND key once again to select the batch. The display will flash FILE F-04 (or the selected batch).

6. Press the MEM key, to access the memory locations in the batch selected. The display will flash the current memory location (L007, L039, etc.), followed by the status of

the memory location. The memory location can contain one of three possible things:

• a measurement that was previously stored

• CLr in the display, indicating that the memory location is empty

• ObSt (obstruct) in the display, indicating that a measurement could not be obtained

7. Press the UP / DOWN arrow keys to advance to the desired memory location.

8.2 STORING A MEASUREMENT

1. Take a measurement and press the SEND key to store a reading in the memory location. The data logger will then automatically advance to the next memory location in sequential

order.

2. Repeat step 1 as required.

8.3 DELETING CONTENTS OF A MEMORY LOCATION

The user may require a memory location that is currently full to be over written. The procedure for deleting (clearing) the contents of the memory location is outlined in the following steps:

Note: This procedure assumes the steps in 8.1 and 8.2 have been completed, a nd 8.2 is being repeated.

1. Press the UP / DOWN arrow keys to move to the memory location to be cleared. If the memory location is currently full, the display will flash the FuLL symbol.

2. Press the CLR key to delete the contents of the memory location. The display will flash the memory location (L011, L099, etc.) and the CLr symbol.

3. Take another measurement, and press the SEND key to write to the same memory location just cleared.

8.4 DELETING CONTENTS OF AN ENTIRE BATCH

The user may require the contents of an entire batch to be cleared of all measurements. This would allow the user to start a new list of measurements starting at memory location L001, for example. The procedure is outlined in the following steps:

1. Press ON/OFF key to switch on the gauge.

2. Press MEM key to activate the data logging functions and settings.

3. Press SEND key to enter batch setup.

4. Press UP / DOWN arrow keys to scroll to the batch that is to be cleared of all measurements.

5. Press SEND key once again to select the batch. The display will flash FILE F-05 (or the batch selected).

6. Press UP / DOWN arrow keys to scroll to the flashing CLr F-05 (or the batch selected).

7. Press SEND key to select the clear batch option. The display will show CLr?

8. Press CLR key to confirm and clear the contents of the entire batch.

9. Press MEM key at any time to exit data logging functions.

8.5 DELETING CONTENTS OF ALL BATCHES

1. Press ON/OFF key to switch on the gauge.

2. Immediately press the

3. Press CLR key once again to clear all batches.

CLR ke

y. The display will show CLr?

9 TRANSFERRING READINGS TO A COMPUTER - CG50/CG50DL ONLY

Readings can be transferred from the Model CG50 and Model CG50DL to a computer. The Model CG50 will transfer readings as they are taken. The Model CG50DL will transfer readings as they are taken and also transfer the contents of its memory.

A data transfer cable is used to connect the gauge to the computer. This cable is supplied with the Model CG50DL and is available as an optional accessory for the Model CG50 (see “Spares” on page 19).

Elcometer NDT recommends the use of NDT Link communications software to transfer the data see “Data transfer software” on page 23. Other types of software may also be used.

9.1 DATA TRANSFER SOFTWARE

Software is available which allows data to be transferred from your gauge to a PC. Presently Elcometer NDT supplies NDT Link software for this purpose.

To set-up other types of communications software:

1. Start the communications software.

2. Configure the software using the following parameters:

Data Bits - 8, Parity - None, Stop Bits - 1, Baud Rate 1200 (to print a report), or 9600 to transfer data file. Note: A report can be printed to a communications program (i.e. HyperTerminal), or printed to

a serial printer using A4 or 8.5" x 11" paper.

3. Set the communications software COM port to the port number that the gauge is connected to.

9.2 TRANSFERRING MEASUREMENT DATA TO YOUR COMPUTER

9.2.1 RS-232 Connector

The RS-232 connector, located on the bottom end cap of the gauge, is a 2 pin female Lemo

OFF

connector. It is designed to connect directly

from the gauge to a standard AT serial port on

a PC. A Lemo to 9 pin serial cable is supplied with the Model CG50DL and is available as an accessory for the Model CG50, see “Spares” on page 19.

RS232 data connection socket

Figure 6. RS232 data connection socket

9.2.2 Computer System Requirements

NDT Link will run on many different operating systems: Windows 98 (1st or 2nd edition), Windows NT 4.0 with Service Pack 5, Windows ME, Windows XP, Windows 2000 Professional, Windows 2000 Server, or Windows 2000 Advanced Server operating systems running on Intel or AMD hardware. A Pentium 166MHz or faster processor with at least 32 megabytes of physical RAM is required. You should have 40 megabytes of free disk space before attempting to install NDT Link. NDT Link requires an available communications port in order to transfer data to and from the gauge. NDT Link supports COM1, COM2, COM3, and COM4.

9.2.3 USB to Serial Converter

Some newer laptop computers do not have standard serial ports. In such cases a USB to Serial converter should be used. This is supplied as standard with the Model CG50DL and is available as an accessory for the Model CG50, see “Spares” on page 19.

9.2.4 Installing NDT Link

NDT Link comes on a CD-ROM with an automatic installer program. Place the CD in your computer's CD tray and close the door. Open the CD-ROM by double clicking on the My Computer ICON, then double click on the CD. Finally, double click on the SETUP icon to begin the installation.

Refer to the help section in NDT Link software for the complete operating manual, setup, and operation.

9.3 TRANSFERRING DATA

Model CG50 After taking a measurement, press the SEND key to send the measurement to the computer.

Model CG50DL TRANSFERRING ONE BATCH

1. Connect the gauge to a computer and start the data transfer software - see “Transferring readings to a computer - CG50/CG50DL only” on page 17.

2. Press ON/OFF key to switch on the gauge.

3. Press MEM key to activate the data logging functions and settings.

4. Press SEND key to enter batch setup.

5. Press UP / DOWN arrow keys to scroll to the batch that is to be sent to the computer.

6. Press SEND key once again to select the batch. The display will flash FILE F-05 (or the batch selected).

7. Press UP / DOWN arrow keys to scroll to LISt F-05 (or the batch selected) flashing on the display.

8. Press the SEND key to send readings to the computer. The display will show buSY during data transfer. Wait until all the data has been transferred.

9. Press the MEM key to exit the data logging functions.

TRANSFERRING ALL BATCHES

1. Connect the gauge to a computer and start the data transfer software - see “Transferring readings to a computer - CG50/CG50DL only” on page 17.

2. Press ON/OFF key to switch on the gauge.

3. Press MEM key to activate the data logging functions and settings.

4. Press UP / DOWN arrow keys to scroll to SEnd ALL flashing on the display.

5. Press the SEND key to send readings to the computer. The display will show buSY during data transfer. Wait until all the data has been transferred.

6. Press the MEM key to exit the data logging functions.

Press the MEM key, at any time, to exit the data logging functions.

10 STORAGE

Your gauge has a Liquid Crystal Display. If the display is heated above 50°C (120°F) it may be damaged. This can happen if the gauge is left in a car parked in strong sunlight.

Always store the gauge in its case when it is not being used.

If the gauge is to remain unused for long periods of time, remove the batteries and store them separately. This will prevent damage to the gauge in the event of malfunction of the batteries.

11 MAINTENANCE

The Models CG30/CG50/CG50DL are designed to give many years reliable service under normal operating and storage conditions.

The transducer will wear with repeated use. Transducer life depends on the number of measurements taken and the manner in which readings are taken. To extend transducer life, always set the transducer down so that it is perpendicular to the panel surface. Dragging the transducer along the surface will reduce the life of the transducer.

Replacement transducers are available from your local Elcometer NDT sup plier or directly from Elcometer NDT.

The gauge does not contain any user-serviceable components. In the unlikely event of a fault, the gauge should be returned to your local Elcometer NDT supplier or directly to Elcometer NDT. The warranty will be invalidated if the instrument has been opened. Contact details can be found at www.elcometerndt.com.

12 TECHNICAL SPECIFICATION

Range: 0.63 mm to 500 mm (0.025" to 19.999") Resolution: 0.01 mm (0.001") Accuracy: ±0.1 mm (±0.004"), depends on material and conditions Sound-velocity range: 1250 m/s to 10 000 m/s (0.0492 in/μs to 0.3937 in/μs) Weight: 295 g (10 oz) including batteries Size: 63.5 mm x 120.6 mm x 31.5 mm (2.5" x 4.5" x 1.24") Operating temperature: -30°C to 50°C (-20°F to 120°F) (depending upon climatic conditions) Case: Extruded aluminium body

Nickel plated aluminium end caps

Battery type: 2 x LR6 (AA), alkaline dry batteries or rechargeable

Battery life: 200

hours continuous (alkaline dry batteries)

13 SPARES

equivalents

The following consumables, replacement and optional items are available from your local Elcometer NDT supplier or direct from Elcometer NDT.

Description Sales Part No.

2.25 MHz 1/4” Potted Side Transducer TX2M25CP-2 5 MHz 1/4” Potted Side Transducer TX5M00CP-4 5 MHz 1/4” Potted Side High Damped Transducer TX5M00CP-10 7 MHz 1/4” Potted Side High Damped Transducer TX7M50CP-6 10 MHz 1/4” Potted Side Transducer TX10M0CP-4 Ultrasonic Couplant, 120 ml (4 oz) TC-24034-1 Ultrasonic Couplant, 360 ml (12 oz) TC-24034-2 Ultrasonic Couplant, High Temperature 340°C (650°F), 60 ml (2 oz) TC-24034-4 Ultrasonic Couplant, High Temperature 480°C (896°F), 60 ml (2 oz) TC-24034-5 RS232 Cable USB to Serial Converter TL-24031

Note: A wide range of other transducers and accessories are available - see www.elcometerndt.com

1. Rechargeable batteries can be used if they are charged outside the gauge.

2. Battery life is reduced to approximately 120 hours when using rechargeable batteries. Follow the instructions provided by the battery manufacturer when charging and disposing of rechargeable batteries.

14 WARRANTY

Elcometer NDT warrants the Model CG30, CG50 and CG50DL ultrasonic gauges against defects in materials and workmanship for a period of two years from receipt by the end user.

Additionally, Elcometer NDT warrants transducers and accessories against such defects for a period of 90 days from receipt by the end user. If Elcometer NDT receives notice of such defects during the warranty period, Elcometer NDT will either, at its option, repair or replace products that prove to be defective. The warranty will be invalidated if the gauge has been opened.

Should Elcometer NDT be unable to repair or replace the product within a reaso nable amount of time, the customer's alternative exclusive remedy shall be refund of the purchase price upon return of the product.

14.1 Exclusions

The above warranty shall not apply to defects resulting from: improper or inadequate maintenance by the customer; unauthorised modification or misuse; or operation outside the environmental specifications for the product.

Elcometer NDT makes no other warranty, either express or implied, with respect to t his product. Elcometer NDT specifically disclaims any implied warranties of merchantability or fitness for a particular purpose. Some states or provinces do not allow limitations on the duration of an implied warranty, so the above limitation or exclusion may not apply to you. However, any implied warranty of merchantability or fitness is limited to the two-year duration of this written warranty.

This warranty gives you specific legal rights, and you may also have other rights, which may vary from country to country, state to state or province to province.

14.2 Obtaining service during warranty period

If your hardware should fail during the warranty period, contact Elcometer NDT and arrange for servicing of the product. Retain proof of purchase in order to obtain warranty service.

For products that require servicing, Elcometer NDT may use one of the following methods:

• Repair the product

• Replace the product with a re-manufactured unit

• Replace the product with a product of equal or greater performance

• Refund the purchase price.

14.3 After the warranty period

If your hardware should fail after the warranty period, contact Elcometer NDT for details of the services available, and to arrange for non-warranty service.

15 TRANSDUCERS

Your gauge is capable of performing measurements on a wide range of materials, from various metals to glass and plastics. Different types of material, however, have different properties. The following paragraphs highlight the important properties of transducers which should be considered when assessing a particular measurement task.

The best measurement condition is one where sufficient ultrasonic energy is sent into the material being measured such that a strong, stable echo is received by the gauge.

Several factors affect the strength of ultrasound as it travels. These are outlined below:

15.1 INITIAL SIGNAL STRENGTH

The stronger a signal is to begin with, the stronger its return echo will be. Initial signal strength is largely a factor of the size of the ultrasound emitter in the transducer. A large emitting area will send more energy into the material being measured than a small emitting area. Therefore a 6 mm (1/4”) transducer will emit a stronger signal than a 3 mm (1/8”) transducer.

15.2 ABSORPTION AND SCATTERING

As ultrasound travels through any material, it is partly absorbed. If the materials through which the sound travels have any grain structure, the sound waves w ill experience scatter ing. Both of these effects reduce the strength of the waves.

Higher frequency ultrasound is absorbed and scattered more than ultrasound of a lower frequency. It may seem therefore that using a lower frequency transducer might be better in every instance, however low frequencies are less directional than high frequencies.

15.3 GEOMETRY OF THE TRANSDUCER

The physical constraints of the measuring environment sometimes determin e the suitability of a transducer for a given job. The transducer may simply be too large to be used in confined areas. Also, the surface area available for contacting with the transducer may be limited. Measuring on a curved surface may require the use of a transducer with a matching curved wearface.

15.4 TEMPERATURE OF THE MATERIAL

When it is necessary to measure on surfaces that are exceedingly hot, special high-temperature transducers may be necessary. Additionally, care must be taken when performing a ‘Calibration to Known Thickness’ with a high temperature application - see “Measuring hot surfaces” on page 22.

15.5 SELECTING THE CORRECT TRANSDUCER

Elcometer NDT have a complete range of transducers to meet your requirements, including:

• A range of frequencies and sizes

• Straight and right angle

• Transducers available as potted or microdot transducers:

Potted transducers - transducer cable is permanently fixed to the transducer head. Microdot transducers - transducer cable is fixed to the transducer head by a connector - allows

transducer heads to be replaced quickly and easily.

• High temperature transducers - temperature up to 480°C (896°F)

When selecting a transducer, it is important to choose one which will best meet your application, taking into consideration:

• The measurement range

• The type of material to be tested

• The design of the transducer probe type

For full details of the Elcometer NDT range of transducers contact your local Elcometer NDT supplier, or visit the Elcometer NDT website www.elcometerndt.com

16 CONDITION AND PREPARATION OF SURFACES

The shape and roughness of the test surface are of paramount importance when carrying out ultrasonic thickness testing. Rough, uneven surfaces may limit the penetration of ultrasound through the material, and result in unstable, and therefore unreliable, measurements.

The surface being measured should be clean, and free of any small particles, rust, or scale. The presence of such obstructions will prevent the transducer from seating properly against the surface. Often, a wire brush or scraper will be helpful in cleaning surfaces. In more extreme cases, rotary sanders or grinding wheels may be used, tho ugh care must be taken to p revent surface gouging, which will inhibit proper transducer coupling.

Extremely rough surfaces, such as the pebble-like finish of some cast iron, will prove most difficult to measure. These kinds of surfaces act on the sound beam like frosted glass acts on light, the beam becomes diffused and scattered in all directions.

In addition to posing obstacles to measurement, rough surfaces contribute to excessive wear of the transducer, particularly in situations where the transducer is ‘scrubbed’ along the surface.

17 APPLICATION NOTES

17.1 MEASURING TUBING

When measuring a piece of pipe to determine the thickness of the pipe wall, orientation of the transducers is important.

If the diameter of the pipe is larger than approximately 100 mm (4”), measurements should be made with the transducer oriented so that the gap in the wearface is perpendicular (at right angles) to the long axis of the pipe.

If the diameter of the pipe is small, two measurements should be performed, one with the wearface gap perpendicular to the long axis of the pipe, another with the gap parallel to the long axis of the pipe (Figure 7). The smaller of the two displayed values should then be taken as the thickness at that point.

Perpendicular Parallel

Figure 7. Transducer positioning on small diameter pipe

17.2 MEASURING HOT SURFACES

The velocity of sound through a material depends upon the temperature of the material. As materials heat up, the velocity of sound in the material decreases. In most applications with surface temperatures less than approximately 100°C (~200°F), no special procedures are required. At temperatures above 100°C (~200°F), the change in sound-velocity of the material being measured starts to have a noticeable effect upon the accuracy of ultrasonic measurement.

At such elevated temperatures, it is recommended that the user perform a calibration procedure (see “Calibration” on page 9) on a sample piece of known thickness, which is at, or near, the temperature of the material to be measured. This will allow the gauge to correctly calculate the velocity of sound through the hot material.

When performing measurements on hot surfaces, it may also be necessary to use a high-temperature transducer. It is recommended that the transducer be left in contact with the surface for as short a time as needed to acquire a stable measurement. While the transducer is in

contact with a hot surface, it will begin to heat up, and through thermal expansion and other effects, may adversely affect the accuracy of measurements.

17.3 MEASURING LAMINATED MATERIALS

The density (and therefore sound-velocity) of laminated materials may vary considerably from one piece to another. Some laminated materials may even exhibit noticeable changes in sound-velocity across a single surface. The only way to reliably measure such materials is by performing a calibration procedure on a sample piece of known thickness. Ideally, this sample material should be a part of the same piece being measured, or at least from the same lamination batch. By calibrating to each test piece individually, the effects of variation of sound-velocity will be minimised.

An additional consideration when measuring laminates, is that any air gaps or pockets within the laminate will reflect the ultrasound beam. This will be noticed as a sudden decrease in thickness in an otherwise regular surface. While this may impede accurate measurement of total material thickness, it does provide positive indication of air gaps in the laminate.

17.4 MEASURING THROUGH PAINT AND COATINGS

When measuring through paints and coatings the sound-velocity of the paint/coating may be significantly different from the sound-velocity of the actual material being measured. An example of this would be a mild steel pipe with approximately 0.6 mm (.025") of co ating on the surface. The sound-velocity of the pipe is 5918 m/s (.2330 in/µsec), and the sound-velocity of the paint is 2286 m/s (.0900 in/µsec). If the gauge is calibrated for mild steel pipe and measu res through bo th materials, the actual coating thickness will appear to be 2.5 times thicker than it actually is, as a result of the differences in sound-velocity.

The error can be eliminated by using the echo-echo mode to perform measurements for applications such as these. In echo-echo mode, the paint/coating thickness will be eliminated entirely and the steel will be the only material measured.

17.5 DATA TRANSFER SOFTWARE

Software is available which allows data to be transferred from Models CG50/C G50DL to a PC. Presently Elcometer NDT supplies NDT Link.

The Model CG50 gauge is supplied without any software but NDT Link is available as a free download from the Elcometer NDT website www.elcometerndt.com.

The Model CG50DL gauge is supplied with a CD containing NDT Link.

To set-up other types of communications software

Model CG50 Model CG50DL

1. Start the communications software.

2. Configure the software using the following parameters:

Data Bits - 8, Parity - None, Stop Bits - 1, Baud Rate 1200.

3. Set the communications software COM port to the port number that the gauge is connected to.

1. Start the communications software.

2. Configure the software using the following parameters:

Data Bits - 8, Parity - None, Stop Bits - 1, Baud Rate 1200 (to print a report), or 9600 to transfer data file.

Note: A report can be printed to a

communications program (i.e. HyperTerminal), or printed to a serial printer using A4 or 8.5" x 11" paper.

3. Set the communications software COM port to the port number that the gauge is connected to.

18 SOUND VELOCITIES OF COMMON MATERIALS

Material

Aluminium 6350 0.CG30 Paraffin 2210 0.087 Bismuth 2184 0.086 Platinum 3962 0.156 Brass 4394 0.173 Plexiglas 2692 0.106 Cadmium 2769 0.109 Polystyrene 2337 0.092 Cast Iron 4572 0.180 (Approx) Porcelain 5842 0.230 (Approx) Constantan 5232 0.CG50 PVC 2388 0.094 Copper 4674 0.184 Quartz Glass 5639 0.222 Epoxy Resin 2540 0.100 (Approx) Rubber, Vulcanised 2311 0.091 German Silver 4750 0.187 Silver 3607 0.142 Glass, Crown 5664 0.223 Steel 5918 0.233 Glass, Flint 4267 0.168 Steel, Stainless 5664 0.223 Gold 3251 0.128 Stellite 6985 0.275 (Approx) Ice 3988 0.157 Teflon 1422 0.056 Iron 5893 0.232 Tin 3327 0.131 Lead 2159 0.085 Titanium 6096 0.240 Magnesium 5791 0.228 Tungsten 5334 0.210 Mercury 1448 0.057 W ater 1473 0.058 Nickel 5639 0.222 Zinc 4216 0.166 Nylon 2591 0.102 (Approx)

Sound-velocity (m/s)

Sound-velocity (in/µs)

Material

Sound-velocity (m/s)

Sound-velocity (in/µs)

Elcometer CG30, CG50DL, CG50 Operating Instructions Manual

Specifications and Main Features

Frequently Asked Questions

User Manual