MFD350B Ultrasonic Flaw Detector




Measuring range:

0 to 6000 mm, at steel velocity

Resolution Accuracy:

Horizontal: +/-0.2% FSW, Vertical: 0.25% FSH, Amplifier Accu

Communication storage:

USB2.0;100 groups of flaw detecting parameters channels;1000

Working time:

More than 8 hours.

Main unit weight:




Package dimensions:


Total weight:



  • Overview
  • Graphic
  • Technical
  • Configuration
  • Related


  • Overview
  • Graphic
  • Technical
  • Configuration
  • Related
  • Product Overview

      Based on ultrasonic principle, digital ultrasonic flaw detector MFD350B with 320*240 TFT LCD, it can test, orient, evaluate and diagnose various flaws such as crack, lard, air hole in workpiece’s interior swiftly and accurately without any destruction. It can be used in Laboratory as well as in engineering filed. With range of 0-6000mm, it can meet the requirement for general defect inspection in manufacturing industry, metallurgical industry, metal processing industry, chemical industry and so on. Low power design with large capacity and high performance lithium battery module, it can be long standby for months. High quality with low price, it is the first choice for the practical economic model for ultrasonic testing equipment.

    Function & application

    The instrument can be widely used in locating and sizing hidden cracks, voids, disbands and similar discontinuities in welds, forgings, billets, axles, shafts, tanks, pressure vessels, turbines and structural components.

    Working Principle

    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.

    Working Conditions

    Operating Temperature: -10 to 50;

    Storage Temperature-30 to 50

    Relative Humidity: (20 ~ 95)% RH

    The surrounding environment should avoid of vibrating, strong magentic field, corrosive medium and heavy dust.

    Instrument Features

    Gate Alarm

    Gate position, gate width and gate height can be adjustable at will. The B gate can chose to set wave-getting alarm or wave-losing alarm. The beep in gate and LED light can be alarmed or closed (the LED light alarm is very effective under the noise environment).

    Data Storage

    The instrument is built with mass storage, the data and files will not be lost because of instrument power breakdown. The storage contents included channel parameters, waveform pictures and video files. It supports 100 groups of flaw detecting parameters channels. It can preset well for the combination parameters of various types of probes and instruments as well as set testing standards for each industry freely. It can save 1000 pictures of detecting echo signals and parameters. It can realize to save, read and transfer the data via the USB port.

    Video Function

    The instrument supports for saving the inspection process as video file and save it to the internal storage card. Video file can be replayed through the instrument. The instrument can support 2 minutes video. 


    Record and save the tracking record of detecting date and time in real time.


    With USB2.0 high speed communication interface, it also can use special software to upload and download data through the USB port.

    Battery Module

    The large capacity lithium battery module is easy to be assembled and disassembled. It can be charged independently but also charged by inserting wire. Its continuously working time is more than 8 hours.  

    Operating Method and Attentions

    Simple Operation Way:

    1. Connect the probe to instrument with probe cable

    2. Power on the instrument

    3. Choose the channel and clear the present channel

    4. Calibration the probe

    Straight Probe: P-Delay

    Angle Probe: P-Delay, X-value, Angle

    5. Make AVG curve (straight probe), DAC curve (angle probe)

    6. Choose the function setting

    7. Detecting flaw in the workpiece

    8. Record the flaws

    9. Power off the instrument after operation


    1. During pressing key operation, please not be too hard. Please not use the hands with much oil or mud for operating the instrument keypad to avoid affecting the keypad working life.

    2. Please clear the instrument cover after operation

    3. Please keep the instrument in a dry and clean place

    4. Please avoid oil, water or other liquids into the instrument and clean the instrument surface regularly.

    5. Make sure not twist or press the probe cable, communication cable and power cable. Please grasp the plug root during inserting or pulling the cable. Don’t grasp the cable for pulling or inserting.

    6. Please make sure the standard battery for working power adapter for charging. Otherwise, the instrument would be damaged easily.


    Instrument Maintenance

    1. 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).


    Do not use any methyl alcohol, solvents, or dye penetrated cleaners!

    The plastic parts can be damaged or embrittled by these.

    2. Care of the Batteries

    Capacity and life of batteries mainly depend on the correct handling. Please therefore observe the tips below.

    You should charge the batteries in the following cases:

    Before the initial startup

    After a storage time of 3 months or longer

    After frequent partial discharge

    3. Maintenance

    The instrument requires basically no maintenance.


    If the accident occurred during instrument using, the instrument will be abnormal which means the instrument will not be able to use. Please turn off the instrument connection with the battery by putting the battery switch to off. Then, power on the instrument again after waiting one minutes to see if it is back to normal.

    We provide two year’s warranty and life-long maintenance to the instrument. Please kindly contact with our company or agent for instrument repair. Please don’t disassemble the instrument by yourself without our agreement.

  • Display Resolution (320×240 pixels) multi-color TFT LCD
    Blind Area 5MM
    Flaw Sizing Automatic flaw sizing using AVG/AVG or DAC, speeds reporting of defect acceptance or rejection.
    Weld Figure Feature Weld Figure feature can be enabled when detecting the weld parts using angle transducer.
    Auto-Calibration Automated calibration of transducer zero offset and/or material velocity
    Memory be able to store, recall the A-Scan patterns and instrument settings
    Flaw Locating Live display Sound-path, Projection (surface distance), Depth, Amplitude
    Defect Quantification directly display the result with db unit
    Defect characterization calculate the equivalent size of the flaw easily and quickly to facilitate the judgment of artificia
    Curved Surface Correction used to measure the surface distance and depth of defect on a curved surface
    AWS D1.1 one of the AWS(American Welding Society) standa
    Crack Height Measuring measure and display the height of a crack found inside the workpiece
    Magnify Gate spreading of the gate range over the entire screen width
    Video Recording more than 10 minutes
    A Scan Freeze Display freeze holds waveform and sound path data
    Coded Echo Color locate the flaw position
    B-Scan display a graphical cross-section of the workpiece
    Power-Saving Method low power consumption
    Protection Level IP54
    Communication Interface High Speed USB2.0 port
    DataPro Software Y
    Working Language freely switch between Chinese and English
    Total Weight 6.0KG
    Measuring Range (0 ~ 6000) mm at steel velocity
    Bandwidth 0.5 to 10MHz automatic matching according to the probe frequency
    Material Velocity (1000~ 9999) m / s
    Dynamic Range ≥ 36dB
    Vertical Linear Deviation ≤ 3.0%
    Horizontal Linear Deviation ≤ 0.2%
    Resolution > 40dB (5P14)
    Sensitivity Leavings >60dB (flat-bottomed deep hole 200mmФ2)
    Rejection (0 to 80)% Linear without affecting the linearity and gain
    Noise Level ≤ 10%
    Probe Type straight beam probe, angle beam probe, dual element probe, through-transmit probe
    Gates Wave-getting Gate, Wave-losing Gate, Single Gate Reading, Dual Gate
    Alarm Beep Alarm and LED light Alarm
    Power Supply DC 9V
    Working Time >8 hours
    Overall Dimensions 263 × 170 × 61(mm)
    Operating Temperature (-10 ~ 50) ℃
    Relative Humidity (20 ~ 95)% RH
    Pulse Energy Low, Medium and High spike pulse selectable, suitable for various probe
    Pulse Width (0~99.99)µs range with continuous adjustment to match the different frequency probes
    Probe Damping 100Ω、200Ω、400Ω selectable to meet different requirements for resolution and sensitivity
    Sampling 10 digits AD Converter at the sampling speed of 160MHz, waveform of highly fidelity.
    Rectification Positive half wave, negative half wave, full wave, RF
    Gate Reading optional for single gate and double gate reading mode, both peak and edge can trigger it
    Gain 0 dB to 110 dB adjustable in selectable steps 0.1 dB, 1 dB, 2dB and 6dB
    Transducer Connections BNC or LEMO