Additional Information

Accessories:

No.	Item	Quantity
1	GAOTek Flaw Detector with Signal Processing (Varied Pulser Function)	1
2	Straight Beam Probe	1
3	Angle Probe	1
4	Machine-probe Cable	1
5	Battery Module	1
6	Power Adapter (Charger)	1
7	Support Pillar	1
8	Manual	1
9	Instrument Case	1
10	Datapro Software	1
11	USB communication Cable	1

Working Principle

The instrument incorporates many advanced signal processing features including a 15 MHz RF bandwidth to permit testing of thin materials, narrowband filters to improve signal to noise in high gain applications, a spike pulser for applications requiring higher frequencies and a tuneable square wave pulser to optimize penetration on thick or highly attenuating materials. When presence of a defect in a workpiece with homogenous material, due to the defects, it will inform the interface among different mediums between the defect and workpiece. As the acoustic resistance is different at the interface, after the pulsing ultrasonic wave met the interface, it will produce reflection. The reflected energy will be received by the probe. Then it will show a reflection waveform in a certain abscissa position in the display screen which is the defect depth in the workpiece. The height and shape of reflecting wave would be different caused by the different defects which reflect the defect’s character.

Screen Display

The instrument displays are designed to be easy to interpret.

The Instrument has a digital screen for the display of A-Scan.
The status bar above the wave display shows values of range settings and measured values.

The names of the menus or submenus are displayed at the bottom of the screen. The selected menu or submenu is highlighted. Indicated at the right of the display, next to the A-Scan, are the functions of the corresponding menu.

Keys and Rotary Knob Features

The instrument is designed to give the user quick access to all of the instrument’s functions. Its easy-to-use menu system allows any function to be accessed with no more than three key presses.

To access any function:

Functions of the keys:

Home key immediately returns the instrument to the main screen (full screen)
Freeze key freezes the A-Scan
Magnify key expands the gate range to full screen
For turning the instrument On/Off
Db-Step key selects the gain submenus or switch the db step
Gate key – Gate functions selecting gate functions and Gate A/B switch
Range key – Range function selecting
Probe-Delay key – Probe Delay calibration
Probe-Angle key selects the angle calibration functions
Save key performs a data-storage of the A-Scan pattern
Auto-Gain key starts or stops the Auto-Gain function
Envelope key turns the Envelope function on and off
Peak-Hold key turns the Peak-Hold function on and off.
Video key starts or stops recording a segment of the display
DAC-AVG key selects the menus of DAC/AVG
Up Arrow key – Move the cursor up to select the desired function
Down Arrow key – Move the cursor down to the desired function
Searches next echo towards left, or move the cursor to left when inputting digit numbers.
Searches next echo towards right, or move the cursor to right when inputting digit numbers.
Confirms or switches current selection

Rotary knob makes it convenient for handling device parameters and functions.
It supports three operations: turn clockwise, turn counter-clockwise and single press.

Menus and Functions

The instrument menu system consists of several menus, submenus, and functions. It allows the operator to select and adjust various features and instrument settings.

Note that some functions, like RANGE, have both coarse and fine adjustment modes. There are three steps in the fine adjustment mode. Coarse and fine modes are selected by pressing the knob more than once. An icon of “” will appear on the left of the function name when the function is in fine adjustment mode. When the function is in coarse adjustment mode, turning the function knob will produce large changes in the selected function’s value. When the function is in fine adjustment mode, rotating the function knob will change the value by smaller amounts.

Alarm Lights

Two alarm lights appear at the top-right corner front of the instrument’s keypad. One alarm light is marked as ALRM, which is assigned to the gate alarm. When a gate alarm is triggered, this light will illuminate. The other light is marked as PWR indicating power and battery status.

Status	ALRM LED	PWR LED
Gate alarm	Red on	×
Battery charging	×	Flash red/green
Battery charge completed with external power connected	×	Green on
External power connected No battery installed	×	Green on
No external power	×	off

Initial Start-up
Power Supply

Operation Using the Power Supply Unit

Connect the instrument to the mains socket-outlet using the power supply unit. The plug receptacle is at the top left of the instrument. Push the plug of the power supply unit into the plug receptacle until it snaps into place with a clearly audible click. The PWR LED on the keypad of the instrument will light in green color if the connection is properly aligned

Operation Using Batteries

Use a lithium-ion battery pack provided with the instrument for the battery operation.
The battery compartment is situated at the instrument back. The cover is fastened with 4 screws. To insert the battery pack:

Connecting a Probe

To prepare the instrument for operation, you have to connect a probe to it. The instrument is available with the probe connectors BNC (LEMO connectors are optional).

When connecting a probe to the instrument, it’s not only important that the probe’s physical connection be properly made. It’s also important that the instrument is properly configured to work with the installed probe. The Instrument will operate with one or two single-element probes or with a dual-element probe.

To install a single-element probe, connect the probe cable to either of the two ports on the front of the instrument. When two probes or a dual-element probe is connected to the instrument, the “Receive” probe connector should be installed in the right port and the ‘Transmit’ probe connector in the left port.

Connect one single element probe to either port. Connect leads from a Dual Element Probe to both ports.For through-transmission, connect two single element probes to the transmit  and receive ports

Starting the Instrument

To start the instrument, simply press down the On/Off key. If it operates on the internal battery pack, make sure to install the battery pack correctly before starting.The start display of the instrument appears; here you will also see the current software version and the serial number of the instrument. The instrument carries out a self-check and then switches over to stand-by mode.The instrument will automatically reload the last instrument setting. It has a special memory that retains all of its settings even when the power is off.The instrument will shut off automatically when the battery capacity level is too low.

Operation

Display mode selection

Mode A: Common display with explore menu on the foot.

Mode B: Common display with function items on the right and explore menu on the foot. Selection menu is on top level.

Mode A: Any key in F1~F5 is pressed and display mode will change to B.
Mode B: Any key in F1~F5 is pressed and display mode keeps in C but function items on the right of the screen will change accordingly. If is pressed, Display mode will change to A.

Parameter Item Selection

Any parameter item can be selected using shortcut key, function group selection key and function item selection key. The selected parameter item will be highlighted on screen.

For example if we want to change GATE MODE for 1 GATES to 2 GATES in display mode B. Firstly we press F1, secondly we press F4, It will now in Gate Logic setting interface. Press  or   key to move the cursor to GATE MODE item. Finally turn Rotary knob and select 2 GATES item.

Adjusting the Display Range

The function group BASE enables you to make the basic adjustment of the display range. The display on the screen must be adjusted for the material to be tested and for the probe used.

Calibration requires the use of calibrated standard made of the same material as the test piece. Prior to calibrating the instrument/probe combination, the A-Scan display-screen range (the material thickness value represented by the full horizontal width of the screen) will normally be set to a value equal to or slightly larger than the calibrated standard. 

Setting the Material Velocity

Use VEL to set the sound velocity within the test object. Always ensure that the function VEL is correctly set. The instrument calculates all range and distance indications on the basis of the value adjusted here.

Velocity range	Coarse adjustment, in steps as follow
1000 m/s ~ 15000 m/s	2260 m/s 2730 m/s 3080 m/s 3230 m/s 4700 m/s 5920 m/s 6300 m/s

Setting the Display Delay

Here you can choose whether to display the adjusted range (for example 11.8 in (300 mm)) starting from the surface of the test object, or in a section of the test object starting at a later point. This allows you to shift the complete screen display and consequently also the display zero. If the display should for example start from the surface of the test object, the value in D-DELAY must be set to 0. To set the display delay

D-DELAY range	Coarse adjustment	Fine adjustment
-20 μS ~3400 μS	12 pixel space (in μS)	1 pixel space (in μS)

Selecting the Probe Test Mode

You can use the function PROBE to activate the pulse-receiver separation. The following modes are available:

Select the probe model step:

Selecting a Rectification Mode
You can select the rectification mode of the echo pulses according to your application in the function RECTIFY (BASIC→ECHO→RECTIFY).Rectification affects the orientation of the A-Scan on the display screen. The A-Scan represents the pulse (echo) that’s returned from the material being tested to the instrument. The series of echoes looks like the Radio Frequency (RF) signal.

Use the following procedure to select a rectification mode

Configuring the Gates

The gates monitor the range of the test object where you expect to detect a flaw. If an echo exceeds or falls below the gate, an alarm signal is shown via the ALRM LED. The gate chooses the echo for the digital time-of-flight or amplitude measurement.

The instrument has two gates: gate A and B. Gate A and B are independent of one another. Setting the position and characteristics of the A- and B-Gates is the first step to configuring the instrument for flaw detecting or material-thickness measurement. The GATE functions controls not only the location of the A and B-Gates, but also the alarms and other features activated when an A-Scan signal crosses a specific gate.

A-Scan signals crossing the A or B-Gate are evaluated for the purposes of flaw detection and Material-thickness evaluation. When the signal crosses the A or B-Gate, the maximum point (peak) of the signal (in the specific gate) is used for evaluation purposes. The measured value is indicated on the status line.

Selecting a Gate

Selecting a gate by using the GATE SEL function in the GATE submenu

You can also repeatedly pressto switch the selected gate between Gate A and Gate B.
The selected gate will be shown in solid line. The unselected gate will be shown in dashed line.

Positioning Gates

Use the following procedures to set the vertical and horizontal position of the A and B-Gates. Remember that gate position has the following effects on instrument performance:

Setting a Gate’s Starting Point
You can fix the starting point of the gates A or B within the display range.

Coarse adjustment	Fine adjustment
half of a lattice	1 pixel space

Adjusting a Gate’s Width

You can determine the gate width within the display range.

Coarse adjustment	Fine adjustment
12 pixel space	1 pixel space

Setting a Gate’s Threshold (Vertical Position)

You can determine the threshold value of the gates within the range of 0 to 99 % FSH (Full Screen Height) for triggering the LED alarm if this value is exceeded or not reached, depending on the setting of the LOGIC function.

Setting the Pulse Energy Level

Use the function ENERGY to set the pulse voltage. The relative energy with which the pulse fires can be set to 200 V, 300 V, 400 V, 500 V or 600 V.

The setting 400 V and 500 V is recommended for most inspections. HIGH is used for inspections in which maximum sensitivity is import, e.g. for the detection of small flaws. Choose the setting LOW for broadband probes or if narrow echoes are required (better lateral resolution).

To set the pulse energy

Setting the Probe X-Value

The function X-VALUE enables you to set the X-Value (distance between the probe’s leading face and probe index/sound exit point) of the probe used. This value is required for the automatic calculation of the reduced projection distance in angle beam transducer operation.

Adjustment range: 0 in ~ 1.96 in (0 mm ~ 50 mm)

Selecting Units
In the function UNITS you can choose your favourite unit system between METRIC and IMPERIAL unit systems.

Scale Setting

As an alternative to the measured values, the instrument enables to display a scale on the first status line. The scale gives you an overview of the position of echoes.

The following settings are possible:

Select the function SCALE. Then use the knob to set the required display mode.
As an alternative, you can repeatedly press to switch the scale.
Key Sound

The key sound can be turned on or off using the KEY SOUND function located in the HORN submenu (CFG→DISP/SND→KEY SOUND).

Resetting the Instrument

In case the instrument can no longer be operated, or you need to make a basic initialization (factory setting), you can reset the instrument to original.

The instrument can be reset by the RESET ALL function. All the memory data, including the wave files, the channel files and the video files, will be cleared during system reset. And the instrument settings will be reset to default.

To reset the instrument

NOTE:

Connecting to a Computer

The instrument is equipped with a USB port at the upper left of the instrument. The PC can be connected with the instrument via the USB port. A-Scan display, instrument settings, and videos stored in the memory of the instrument can be transferred to the computer through the USB port. Detailed information of the communication software and its usage refer to the Data Pro software manual.

Calibration and Measurement

Before working with the instrument, you have to calibrate the instrument: you have to adjust the material velocity and display range and allow for the probe delay depending on the material and dimensions of the test object.To ensure a safe and proper operation of the instrument, it is necessary that the operator be adequately trained in the field of ultrasonic testing technology.

Below you will find some examples of common calibration methods for certain test tasks.
Calibration with Straight- and Angle-Beam Probes
Case A: With Known Material Velocity
Calibration process

Example:
You are carrying out the calibration with a straight probe for the calibration range of 11.8 in (300 mm) via the function group BASE using the calibration block DB-P (thickness 8.85 in (225 mm)) which is laid flat-wise.

This completes the calibration of the instrument to the material velocity of 5920 m/s with a calibration range of 11.8 in (300 mm) for the straight-beam probe used.
Case B: With Unknown Material Velocity

Use the semiautomatic calibration function of the instrument via the function group CAL for this calibration case.The distances between two calibration echoes must be entered. The instrument will then carry out a plausibility check, calculate the material velocity and the probe delay, and automatically set the parameters using the calculation result.

Calibration Process

The calibration is confirmed by the message “Calibration is finished”. The instrument will now automatically determine the sound velocity and the probe delay and set the corresponding functions accordingly. The value of the function P-DELAY will be set to the correct value.

If the instrument is not able to carry out any valid calibration on the basis of the input values and the echoes recorded, a corresponding error message is displayed. In that case, please check the values of your calibration lines and repeat the process of recording the calibration echoes.

Calibration with Dual-Element (TR) Probes
Dual-element (TR) probes are especially used for wall thickness measurement. The following peculiarities must be taken into account when using these probes:

Echo Flank. Most dual-element (TR) probes have a roof angle (transducer elements with inclined orientation toward the test surface). This causes mode conversions both at beam index (sound entry into the material) and at the reflection from the back wall, which can result in very jagged echoes.

V-Path Error. Dual-element (TR) probes produce a v-shaped sound path from the pulse via the reflection from the back wall to the receiver element. This so-called “V-path error” affects the measuring accuracy. You should therefore choose two wall thicknesses that cover the expected thickness measurement range for the calibration. In this way, the V-path error can be corrected to the greatest possible extend.

Higher Material Velocity. Due to the V-path error, a higher material velocity than that of the test material is given during calibration, especially with small thicknesses. This is typical of dual-element (TR) probes and serves for compensation of V-path error.

With small wall thicknesses, the above-described effect leads to an echo amplitude drop which has to be especially taken into account with thicknesses less than 0.078 in (2 mm).A stepped reference block having different wall thicknesses is required for calibration. The wall thicknesses must be selected so that they cover the expected readings.
Calibration Process

We recommend using the semiautomatic calibration function for the calibration with T/R probes.

The correct calibration is confirmed by the message “Calibration is finished”. The instrument will now automatically determine the sound velocity and the probe delay and set the corresponding functions accordingly. The value of the function P-DELAY will be set to the correct value.If necessary, check the calibration on one or several known calibration lines, e.g. using the stepped reference block.

Distance Amplitude Curve

The instrument is available with Distance Amplitude Curve (DAC) function. Functions for the distance-amplitude curve are accessed through the DAC Menu, which is located by pressing.

When displayed, the DAC curve visually represents a line of constant reflector peaks over a range of material depths. A new feature of the instrument is a multiple-curve option that displays three dB offset DAC curves simultaneously. Each curve represents constant reflector size at varying material depth. Remember that in DAC mode, the only deviation from traditional display and operation is the appearance of the DAC curve. All A-Scan echoes are displayed at their non-compensated height.

A DAC curve is programmed using a series of same-reflector echoes at various depths covering the range of depths to be inspected in the test material. Because near field and beam spread vary according to transducer size and frequency, and materials vary in attenuation and velocity, DAC must be programmed differently for different applications. A DAC curve can be based on up to 16 data points (material depths).These points are recorded from the DAC menu as described below.

Recording the DAC Curve

DAC Curve points are typically taken from a standard with equally sized reflectors (holes) located at various material depths. The primary echo from each of these points (for up to a total of 16 echoes) are recorded. When DAC is active, the instrument displays a curve that represents echo peaks for constant reflectors at varying material depth. Before starting to record a reference curve, the instrument must be correctly calibrated. To program the DAC Curve:

Note that you can change the DAC curve line type between CURVE and DIRECT.

Creating DAC Offset Curves

The three curves can be offset from the original DAC curve (ML) by a user-inputted amount.When operating with DAC turned on, three DAC curves including RL, SL and EL are typically displayed.

The offset range is from -50 dB to 50 dB.

    

Specifying the DAC Reference Curve

Once the DAC curve is recorded and displayed (if not displayed, switch on by turning DAC DISP on), echoes are automatically compared to the size reference curve, which can be specified in the SIZE REF selection. The options include RL, SL, EL, and ML.

The dB equivalent height of the signal above or below the corresponding DAC Reference Curve amplitude is displayed as a comparison result.

Deleting a DAC Curve
To delete a stored DAC curve

Turning On/Off the DAC display
Turning DAC DISP on and off causes the DAC curves to be displayed or removed.

Note that if the DAC curve is not created, it will prompt out “No DAC curve found” and DAC DISP will be set to OFF.
Echo Evaluation with DAC

Curved Surface Correction

When using angle beam transducers on a curved surface the instrument will calculate the surface distance and depth of defect, taking into account the internal or external radius.

THICK: Use the THICK function to set the material’s wall thickness. This value is required for the 30 automatic calculation of the real depth. Adjustment range: 0 in ~ 196.8 in (0 mm ~ 5000 mm)

O-DIAM (Outside diameter of the test object): You will need the CSC function for tests on circular curved surfaces, for example when testing longitudinally welded tubes. In order to make the instrument carry out the corresponding correction of (reduced) projection distance and depth, you should enter the outside diameter of your test object in this function. Adjustment range: 0 in ~ 196.8 in (0 mm ~ 5000 mm)

CSC: If you plan to carry out the flaw position calculation for the curved surface workpieces, the CSC function should be turned on. Otherwise turn off the CSC function.

Flaw Sizing Feature
Using the Flaw Sizing feature, you can calculate the equivalent size of the flaw easily and quickly.

Crack Height Measuring Feature

This feature allows measuring the height of a crack found inside the workpiece. Before starting to use the Crack Height Measure function, the instrument and the probe must be correctly calibrated.

Envelope Function

When the ENVELOPE function is activated, the echoes with the highest amplitude within selected gate will be recorded and displayed statically on the screen additionally to the live A-Scan. And the icon will in the wave window. To activate the ENVELOPE function

Also you can repeatedly press to turn on/off the ENVELOPE function.Note that PEAK HOLD and ENVELOPE cannot function simultaneously.
Peak Hold Feature

When PEAK HOLD is activated, the echo with the highest amplitude in the selected gate becomes the reference echo displayed statically on the screen additionally to the live A-Scan. And the icon will appear on the top-left of the display. You can use this function to record and document the peaked, maximum echo display.

To activate the Peak Hold Feature

Weld Figure Feature

Weld Figure feature can be enabled when detecting the weld parts using angle transducer.Weld parameters should be set before using this feature. Refer to figure.

Data Storage

The instrument is equipped with a data-storage system. A-Scans patterns, instrument settings, and video can be stored in data files for later retrieval. File data can be saved, recalled and deleted by using the MEM menu.

Wave Files

Wave files are used to store A-Scan pattern, along with the instrument settings. Data in the wave files can be stored, recalled and erased.

Wave SAVE
You can save the A-Scan pattern to a wave file using the SAVE function.

Note: The asterisk (*) before a selected file name indicates that this file is already occupied. It is not possible to overwrite an occupied file. Users should select another file name which is still empty, or clear the occupied file to save to. To avoid loss of data e.g. in case of a software update you should save the file to a PC.
Wave RECALL 

You can recall a stored wave file; your instrument will then display all the test-relevant technical features that existed at the moment of the setup. A frozen display of the stored A-Scan appears.

Wave CLEAR

An occupied file is marked with an asterisk (*) before the file name. You can clear the file if you no longer need them. Wave Files are cleared using the CLEAR function.

The file is now cleared; the asterisk preceding the file name is no longer there.
Maintenance and Care
Care of the Instrument
        Clean the instrument and its accessories using a moist cloth. Only use the following recommended instrument cleaners: water, a mild household cleaner or alcohol (no methyl alcohol).
Attention:
Do not use any methyl alcohol, solvents, or dye penetrated cleaners.The plastic parts can be damaged
Maintenance
The instrument requires basically no maintenance.
Safety

The design of the instrument meets safety standard. During the operation, it shall meet the specified external ambient condition, and the operator shall be furnished with concerned technology background, so as to guarantee safe operation.

Charging the Batteries

Internal Charging

If a battery pack is located in the instrument, the charging process is started automatically when you connect the plug-in power supply unit. You can carry out ultrasonic inspections and charge a battery at the same time.The charging time is about 10 hours with a simultaneous ultrasonic inspection. If the instrument is not being used for ultrasonic inspections, the charging time is about 8 hours. This charging time applies to ambient temperatures from 77 °F ~ 86 °F (25 °C to 30 °C). Please take into consideration that the batteries are not charged to their full capacity at higher temperatures.The POWER LED display at the top-right corner of the keypad indicates the status of the charging process. It will flash red/green during the charging process. And the flash will stop when the charging process stops.

External Charging
Lithium-ion batteries can be charged by means of an external battery charger.

Note: