MTU-3 MPI Reference Block Type 1
EN ISO 9934-2:2002
MTU-3 MPI Reference Block Type 1 (also known as MTU Test Block No. 3) is a wet sensitivity
calibration standard block for magnetic particle inspection (MPI),
used to verify the detection capability and system status of
magnetic suspensions/powders. It is the core quality control tool
for non-destructive testing (NDT).
Core functionality
Sensitivity verification: Verify the defect display ability of
magnetic powder/magnetic suspension, and determine whether the
sensitivity has decreased due to aging or contamination.
System quality control: Daily/regular verification of MPI
equipment, magnetic suspension concentration, and lighting
conditions (UV/white light) to ensure compliance.
Benchmark comparison: Comes with a standard reference image, which
compares the measured crack display with the benchmark to determine
whether the system is qualified.
Consumables evaluation: Compare the testing performance of
different brands/batches of magnetic powder and new and old
magnetic suspensions.
MTU-3 MPI Reference Block Type 1 usage and functional analysis
1. Verify the magnetization effect (magnetic field direction and
intensity) | MTU-3 test blocks are usually made of materials with high magnetic
permeability, When the test block is placed on the surface of the
inspected workpiece and magnetized together with the workpiece, The operator determines the direction of the magnetic field on the
surface of the workpiece by observing which directions of defects
display magnetic traces. For example, if only radial cracks are
visible, it indicates that the magnetic field is circumferential;
If only concentric cracks are displayed, it indicates that the
magnetic field is radial. |
2. Evaluate the comprehensive sensitivity of the system | The artificial defects on the test block are very subtle and can
only be clearly displayed when the entire detection system (current
value, magnetization method, magnetic suspension concentration,
cleanliness, lighting conditions, etc.) is in good condition. |
3. Daily performance verification | ·Before starting the testing work every day, or after replacing the
testing process and equipment, using MTU-3 test blocks for a quick
calibration is an important quality control step to ensure the
reliability of the testing results. This meets the regulatory
requirements of high standard industries such as aerospace, nuclear
power, and pressure equipment. |
4. Compare the performance of different magnetic suspensions | ·By using the same MTU-3 test block and the same magnetization
specification, the performance of magnetic suspensions (including
fluorescent and non fluorescent) from different batches or
suppliers can be compared. A better performing magnetic suspension
will result in clearer defect display and higher contrast on the
test block. |
During the magnetic particle testing process, the MTU-3 Type I test
block quickly and intuitively verifies and confirms whether the
comprehensive sensitivity of the entire testing system (including
equipment, magnetization method, magnetic suspension performance,
and operating process) meets the required standards, and displays
the direction of the magnetic field on the workpiece surface.
The MTU-3 MPI Reference Block Type 1 is a key tool for ensuring the
reliability, consistency, and traceability of magnetic particle
testing results.
MTU-3 MPI Reference Block Type 1