Reference Block Type 1 (MTU Test Block Nr. 3)
Use to check the
performance of MPI materials
Use our Reference Block Type 1 (EN-ISO 9934-2, also known
as MTU Test Block No. 3) to test the concentration of your magnetic powder
suspensions, to ensure optimal error indication while carrying out magnetic
particle inspection. The disc is used to check the performance and sensitivity
of of the magnetic particle materials, to allow you to assess the material
degradation and/or bath contamination.
Construction of the Reference Block
The test piece is produced as a disc with a diameter of 50
mm and a thickness of 10 mm. A drilled hole with a diameter of 10 mm is located
at the centre of the block. This drilling hole serves as support of a
magnetising mandrel, for which a magnetising field strength of 24 A/cm is
required within the test piece. The test piece is constructed of an alloy
consisting of steel and vanadium. This construction ensures that, once magnetised,
the reference block will retain its optimum performance as a reference block
for crack indications without the need for further magnetisation.
Crack Pattern
The crack indications that are present on both surfaces of
the reference block are produced by specific grinding and have a size of 0.1 -
1.0 µm. Each reference block has a unique crack pattern. Unlike test pieces
with reproduceable crack widths, our reference block type 1 has ‘net shaped’
crack indications which are designed to mimic ‘naturally grown’ cracks. These
are directly comparable with cracks produced during typical manufacturing
processes.
Applications
Before using the test piece, ensure it is free from dust,
oil and other repellent materials. If necessary, clean with our SKC-S cleaner.
Ensure that the magnetic particle suspension is adequately mixed for at least 5
minutes prior to its application to the reference block. Spray the reference
block on both sides with the magnetic particle suspension. The spraying time
should match the cycle time preselected on the magnetic particle inspection
test unit, to ensure that it reflects the test process. After spraying the
block, place it vertically onto an absorbent cloth so any surplus liquid can
run off, then inspect the crack pattern. Each reference block is supplied with
a certificate which contains reference photographs showing the test results
that were obtained on both sides of the block. These tests were carried out in
accordance with EN-ISO 9934-2 using our 601.1 magnetic powder (average particle
size: 5.0 µm). Compare the test results that you have obtained with these
indications. After the visual test, clean the reference block with SKC-S.
Magnetic powder residue left on the surface for any length of time may lead to
permanent indications being shown
Ordering Information
Reference Block Type 1: 135012 After rinsing with test liquid, the MTU test
block displays the extent to which the test liquid can deliver indications.
Product Properties
NDT Type: Fluorescent
Magnetic Particle Testing, Visible Magnetic Particle Testing