38
en
23.2 CALIBRATION BLOCKS
Elcometer NDT offer a comprehensive range of calibration blocks to suit a wide range of applications and
standards.
Selecting the correct calibration block for the application is essential to ensure accurate evaluation. The
form, shape and material of the calibration block should be appropriate for the material being inspected.
Any artificially induced flaw should closely resemble that of the actual flaw being tested for.
The calibration blocks listed below are a selection of those available - details of the full range can be found
on www.elcometerndt.com
Description
Sales Part No.
Glass Calibration Block, 1”, 2” and 3”
TW-24028
Calibration Bar, 3”, Steel
TW-24029-S1
Calibration Bar, 3” and 6”, Steel
TW-24029-S2
Calibration Block: 8 Step; 1 - 8mm
TW-24005-*
Calibration Block: 10 Step; 2 - 20mm
TW-24006-*
Calibration Block: 10 Step; 2.5 - 25mm
TW-24007-*
Replace * with S1018 = 1018 Steel Block;
A = Aluminium Block; SS = Stainless Steel Block; T = Titanium Block.
23.3 ULTRASONIC COUPLANT
Each gauge is supplied with a 120ml (4oz) bottle of standard ultrasonic couplant. Replacement bottles and
couplant for high temperature applications are available from your local Elcometer NDT supplier or directly
from Elcometer NDT.
Description
Sales Part No.
Ultrasonic Couplant, 120 ml (4 oz)
TC-24034-1
Ultrasonic Couplant, 360 ml (12 oz)
TC-24034-2
Note: A wide range of other transducers and accessories is available - see www.elcometerndt.com for
details.
23.4 MISCELLANEOUS
Description
Sales Part No.
RS232 Cable USB to Serial Converter
TL-24031
24 TRANSDUCERS
Transducer selection is a very important part of getting the best results from your gauge. The frequency and
diameter of transducer should be carefully selected using the following information.
24.1 TRANSDUCER DIAMETER
Select the largest diameter transducer that will seat completely on the end of the bolt. If there are multiple
applications and diameters to consider, select a diameter that will work for as many applications as possible,
thus reducing the overall number of transducers needed.
24.2 FREQUENCY
When selecting the proper frequency, the following items should be taken into consideration:
•
Higher frequencies are typically a better choice when measuring smaller diameter bolts as the sound
is better focused resulting in less beam spread and a more direct path.
•
Lower frequencies are more forgiving of potential bending and attenuating materials. This is primarily
due to the longer wavelength avoiding smearing or distortion of the waveform. Longer wavelengths
require more of a phase shift before distortion will occur. Lower frequencies offer an increased amount
of dispersion and a less direct path. As this may seem to go against what may typically be considered
a good choice, in the case of bending it is actually the best choice overall.
