Dakota Ultrasonics Flaw Detectors

Q: How do DAC, TCG, AVG/DGS, and AWS sizing toolkits differ in flaw evaluation?

DAC (Distance Amplitude Correction): Digitally plots a curve across up to 8 reference reflectors of identical size at increasing depths to compensate for sound attenuation over distance, displaying echo amplitude in %DAC , dB , or %FSH . TCG (Time Corrected Gain): Automatically increases receiver gain with depth (20 dB/µs up to 50 dB dynamic range) so that identical reflectors at different depths appear at the exact same screen height ( %FSH ). AVG / DGS (Distance Gain Size): Uses mathematical probe characteristics and a single reference echo to compare an unknown flaw against an Equivalent Flat-Bottom Hole (ERS) diameter. AWS (American Welding Society D1.1): Automatically computes the weld discontinuity severity rating ( D = A − B − C ) required for structural steel weld acceptance.

Q: Should I choose the Dakota FX70-DL (DFX-7) or the FX80-DL / FX81-DL (DFX-8 / DFX-8+)?

Choose the Dakota FX70-DL (DFX-7) if you need an ultra-portable, one-handed field instrument for rope-access technicians, scaffolding weld inspections, and pipe thickness surveys with USB-C connectivity and a reversible right/left-handed landscape display. Choose the Dakota FX80-DL or FX81-DL (DFX-8 / DFX-8+) if you prefer a large 5.7-inch sunlight-readable color QVGA screen , up to 64GB expandable SD memory, dual Li-Ion + AA battery packs, or require 0–10V analog outputs, B-Scan crawler encoder inputs, hardware alarm relays, and an Auto Interface Gate for immersion tank testing .

F.A.Q.

What is the difference between an ultrasonic thickness gauge and an ultrasonic flaw detector?

A standard Ultrasonic Thickness Gauge uses a straight-beam (typically dual-element) probe to measure wall thickness parallel to the surface for corrosion and erosion monitoring. An Ultrasonic Flaw Detector—such as the Dakota FX70-DL or Dakota FX80-DL—supports both straight-beam thickness gauging and angle-beam shear wave inspection, adding high-speed A-Scan waveform analysis, trigonometric beam-path location, and DAC, TCG, AVG/DGS, and AWS D1.1 defect sizing to locate internal cracks, voids, and weld defects oriented at an angle to the surface.

How do DAC, TCG, AVG/DGS, and AWS sizing toolkits differ in flaw evaluation?

DAC (Distance Amplitude Correction): Digitally plots a curve across up to 8 reference reflectors of identical size at increasing depths to compensate for sound attenuation over distance, displaying echo amplitude in %DAC, dB, or %FSH.

TCG (Time Corrected Gain): Automatically increases receiver gain with depth (20 dB/µs up to 50 dB dynamic range) so that identical reflectors at different depths appear at the exact same screen height (%FSH).

AVG / DGS (Distance Gain Size): Uses mathematical probe characteristics and a single reference echo to compare an unknown flaw against an Equivalent Flat-Bottom Hole (ERS) diameter.

AWS (American Welding Society D1.1): Automatically computes the weld discontinuity severity rating (D = A − B − C) required for structural steel weld acceptance.

Should I choose the Dakota FX70-DL (DFX-7) or the FX80-DL / FX81-DL (DFX-8 / DFX-8+)?

Choose the Dakota FX70-DL (DFX-7) if you need an ultra-portable, one-handed field instrument for rope-access technicians, scaffolding weld inspections, and pipe thickness surveys with USB-C connectivity and a reversible right/left-handed landscape display.

Choose the Dakota FX80-DL or FX81-DL (DFX-8 / DFX-8+) if you prefer a large 5.7-inch sunlight-readable color QVGA screen, up to 64GB expandable SD memory, dual Li-Ion + AA battery packs, or require 0–10V analog outputs, B-Scan crawler encoder inputs, hardware alarm relays, and an Auto Interface Gate for immersion tank testing.

Are transducers and angle-beam wedges included with the flaw detector kit?

Because NDT applications vary widely between structural weld inspection (1 MHz to 5 MHz shear wave probes with 45°, 60°, or 70° wedges), heavy castings, and thin-wall corrosion testing, transducers and wedges are ordered separately to match your exact material and code specification. Browse our dedicated Flaw Detector Transducers page to select Single-Element Contact, Shear Wave Quick-Change, Delay Line, and AWS Snail Wedges.