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DFX-7 Ultrasonic Flaw Detector & Thickness Gauge

Made in USA
DFX-7 Dakota Ultrasonic Flaw Detector
Click images to enlarge.
The Dakota DFX-7 is both, an ultrasonic flaw detector, as well as an ultrasonic A/B Scan thickness scope, in a single unit. Thickness gauge are specifically setup to very accurately measure thickness, locate pits, flaws and blind surface corrosion. All the linearity tables, correction curves for various types of longitudinal transducers and features are built with dimensional thickness as its primary focus. Flaw detectors are designed to detect, size, position, and differentiate between flaw types in various materials and welded joints. A flaw detector must be fast, in terms of its sample and screen refresh rate, as inspectors are generally scanning the surface of a part or test specimen at a relatively high speed, rather than looking for the thickness at a specific point or location. While flaw detectors can also measure material thickness with reasonable accuracy, they are not designed with precision thickness as their primary focus. The DFX-7 combines the two types of gauges into one powerful and full featured instrument, that’s equipped with a number of comprehensive toolkits to provide the user the arsenal necessary to address a number of common field applications.

The DFX-7 has the ability to simultaneously measure coatings and material thicknesses while maintaining the ability to locate pits, flaws and defects in the material. Based on the same operating principles as SONAR, the DFX-7 is capable of measuring the thickness of various materials with accuracy as high as ± 0.001 inches, or ± 0.01 millimeters. The principle 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 two versions of the DFX-7 series: DFX-7 and DFX-7+. The DFX-7 is a wide band only gauge, which includes a single wide band filter with a range of 1.8MHz to 19MHz. The DFX-7+ includes the same wide band filter, but also includes a few narrow band filter options at 2MHz, 5MHz and 10MHz. The wide band option is responsive to all signals within the given frequency range. However, narrow band filters eliminate signals outside of the target filter frequency, and focus on the output of the transducer at the specified frequency.

Also known as FD700


Flaw Detector Features
  • TRIG: Trigonometric display of beam path, depth, surface distance, and curved surface correction. Used with angle beam transducers.
  • DAC: Up to 8 points may be entered and used to digitally draw a DAC curve. Reference -2, -6, -10, (-6/-12), (-6/-14), (-2/-6/-10) dB. Amplitude displayed in %DAC, dB, or %FSH.
  • AWS: Automatic defect sizing in accordance with AWS D1.1 structural welding code.
  • AVG/DGS: Automatic defect sizing using probe data. Stores up to 64 custom setups.
  • TCG: Time corrected gain. 50 dB dynamic range, 20 dB per microsecond, up to 8 points for curve definition.
  • Measurement Mode: Pulse-Echo (P-E) range 0.025 in to 100 ft. (0.63mm to 3048 cm).
  • Auto-Cal: Provides automatic calibration with two reference points.
  • Detection Modes: Zero Crossing, Flank and Peak.
  • Display Freeze: Hold current waveform on screen.
  • Peak Memory: Captures peak signal amplitude.
  • Skip Bar: Displays skip legs in the waveform area
Thickness Gauge Features
  • One and two point calibration option for material & coating, or selection of basic material types.
  • Auto probe zero, recognition and temperature compensation.
  • High speed scan up to 50 readings per second.
  • Audible alarm with hi/lo limits.
  • Built-in differential mode for QC inspections.
  • Linear time dependent gain (TDG) with adjustable slope (dB per microsecond).
Measurement Modes (Dual & Single Element):

  • Pulse-Echo Mode (P-E) - (Pit & Flaw Detection) range 0.025 to 96 in (0.63mm to 244 cm). Single Contact - 0.040 in to 100 ft. (1 mm to 3048 cm).
  • Pulse-Echo Coating Mode (PECT) - (Material, Coating, Pit & Flaw Detection): Material: 0.025 in to 96 in (0.63mm to 244 cm). Coating: 0.001 to 0.100 inches (0.01 to 2.54 millimeters).
  • Pulse-Echo Temp Comp Mode (PETP) - (Pit & Flaw Detection) Auto temperature compensation-range 0.025 in to 96 in (0.63 mm to 244 cm).
  • Echo-Echo Mode (E-E) - (Thru Paint & Coatings) range 0.050 to 4.0 inches (1.27 to 102 millimeters). Single Delay Line - 0.007 to 1.00 in (.178 to 25.4 mm). Single Contact - 0.040 in to 10 ft. (1 mm to 305 cm). Will vary based on coating.
  • Echo-Echo Verify (E-EV) - (Thru Paint & Coatings) range 0.050 to 1.0 inches (1.27 to 25.4 millimeters). Will vary based on coating.
  • Coating Only Mode (CT) - (Coating Thickness) range 0.0005 to 0.100 inches (0.0127 to 2.54 millimeters). Range will vary +/- depending on the coating.

New Features

  • USB-C connectivity
  • 4 GB internal SD memory card.
  • PRF adjustable up to 2000Hz.
  • New landscape A-Scan view (right & left hand) – 2.7" waveform view.
  • Skip Bar feature for easy reference (TRIG leg bar).
  • Screen Capture to .tif file for quick documentation/reference.
  • Time dependent Gain (TDG) with adjustable slope
  • Date & time stamp
  • 5v external power via USB-C to PC or USB cell phone power adapter.

Complete Kit

The DFX-7 comes complete with DakView3 PC software and cables, 4 oz bottle of couplant, operating manuals and calibration certificate in a plastic carrying case.


Size2.5W x .5H x 1.24D in (63.5 x 165 x 31.5mm)
Weight14 ounces (.397kgs), with batteries
CaseExtruded aluminum body with nickel plated aluminum end caps (gasket sealed)
Display1/4 VGA AMOLED color display (320 x 240 pixels). Viewable area 1.7 x 2.27 in (43.2 x 57.6 mm). 16 color pallete, multiple color options, and variable brightness
Screen Refresh Rate60Hz
Display ViewsFlaw Detector: Full wave, +/- Rectified, or RF. Thickness Gauge: Digits, +/- Rectified, RF, or B-Scan
Resolution (selectable)± 0.001 in (0.01 mm) or ± 0.0001 in (0.001mm)
TimingPrecision 25MHz TCXO with single shot 100 MHz 8 bit ultra low power digitizer
Measurement GatesTwo independent gates (Flaw), and three gates (thickness). Start & width adjustable over full range. Amplitude 5-95%, 1% steps. Positive or negative triggering for each gate with audible and visual alarms
Operating Temperature14 to 140F (-10C to 60C)
EnvironmentalMeets IP65 requirements
Warranty2 years
Automatic CalibrationLongitudinal (straight), or Shear (angle)
Probe TypesSingle Contact, Dual, Delay, and Angle
UnitsEnglish (in), Metric (mm), or Time (µs)
Velocity0.0100 to .6300 in/µs (256 - 16,000 m/s)
Test Range0 to 0.280in (7.11mm) minimum, to 1200in (30,480mm) maximum at steel velocity. Continuously variable
Zero Offset (Probe Zero)0 - 999.999 µs
Material Velocity TableContains longitudinal and shear velocities for a variety of material types
Pulser TypeTwo adjustable square wave pulsers and receivers
P.R.F.8 to 333Hz in selectable steps (8, 16, 32, 66, 125, 250, 333Hz)
Pulser Voltage200 volt peak amplitude, rise/fall time < 10ns into 50ohm
Pulse Width40 to 400 ns. Selectable step options (spike, thin or wide)
Gain0 to 110dB with 0.2dB resolution. Manual and AGC control
Damping50, 75, 100, 300, 600, & 1500 ohms
Frequency BandsDFX-7 & 7+: Broadband 1.8 – 19 MHz (-3dB)
DFX-7+: Three narrow bands centered at 2MHz, 5MHz, 10MHz
Horizontal Linearity± 0.4% FSW
Vertical Linearity± 1% FSH
Amplifier Linearity± 1 dB
Amplitude Measurement0 to 100% FSH, with 1% resolution
Delay0 - 999in (25,375mm) at steel velocity
Log FormatsGrid (Alpha Numeric), or Sequential (Auto Identifier)
Capacity4 Gb internal SD card
Screen CaptureBitmap graphic capture for quick documentation (.tif )
Custom Setups64 user configurations
Power Source
BatteryThree 1.5V alkaline, 1.2V AA Nicad cells, 1.2V AA NI-MH, or other other equivalent power source
Battery life (continuous use)Alkaline (12hrs), Nicad (5hrs), and NI-MH (12hrs), with default settings
Line PowerUSB-C to PC or power outlet
OutputDirect USB-C 1.1 PC connectivity
Transducer ConnectionsTwo LEMO 00 connectors
Thickness GaugeFactory calibration traceable to NIST & MIL-STD-45662A
Flaw DetectorEN12668-1 compliant


Buy Now

Item Description Price
Dakota DFX-7 Flaw Detector Complete Kit, Z-220-0003, Transducers Sold Separately
Dakota DFX-7+ Flaw Detector Complete Kit, Z-221-0003, Transducers Sold Separately
DakView3 PC Software
Instrument Case with Straps for DFX-7 Series
6 foot RS232 Cable (DB-9 to Lemo 2 pin)
USB to Serial Adapter
Operator Manuals for DFX-7 (Flaw)
Operator Manuals for DFX-7 (Thickness)
Plastic Carrying Case for Dakota / TI Gauges
Coupling Fluid - 4oz - V-000-0001
Coupling Fluid - 12oz - V-000-0003
High Temp Coupling Fluid 4 oz / 118 ml (0 - 600 F / -18 to 316 C)
High Temp Coupling Fluid 4oz (600 - 780 F / 316 - 404 C)
1/4" diameter, 5.0 MHz, dual element transducer, Side In, Potted
1/4" diameter, 5.0 MHz Hi-Damped transducer for thru paint measurement, Side In, Potted
1/4" diameter, 5.0 MHz, dual element, through-coating transducer, Side In, Potted
Protective Rubber Boot for Tall Format Ultrasonic Thickness Gauges
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