where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -

The Specialist of electronics for ultrasonic testing.

Technical Discussions
Israel, Joined Sep 2017, 4


Joined Sep 2017
14:31 Jan-09-2019
Water US TT material frequency attenuation

I used a water through transmission method to measure and calculate frequency dependent ultrasound attenuation in several materials, by applying FFT to each waveform and comparing the amplitude of the signals at each frequency (Water TT vs Sample+Water TT).
In case of highly attenuating materials I had to increase the gain in Sample+Water TT case such that the amplitude of Sample+Water TT signal at Gain Y was equal to the amplitude of Water TT signal at Gain X (X<Y). In this case the difference Y-X in dB is the ratio of amplitudes between the two signals.
The problem is, that now I don't know how to compare the signals in frequency domain. Due to increased gain the signal in Sample+Water TT case has higher amplitude than in Water TT case.
Merely decrease the amplitude of first signal by Y-X dB and compare the result to second signal seems me wrong since the amplitude of received signal in frequency domain is not proportional to increase in Gain in time domain...
Any ideas?

Edward Ginzel
R & D, -
Materials Research Institute, Canada, Joined Nov 1998, 1254

Edward Ginzel

R & D, -
Materials Research Institute,
Joined Nov 1998
15:04 Jan-09-2019
Re: Water US TT material frequency attenuation
In Reply to Alex at 14:31 Jan-09-2019 (Opening).

Alex, in a paper I prepared for NDT.net (https://www.ndt.net/article/ndtnet/2016/17_Ginzel.pdf) I used a similar configuration and several of the materials were highly attenuative. The paper references an Excel template that Ben Turnbull prepared for me to do what you are also doing in TT. The template was uploaded to the forum at
The template is open to see all the equations used. If you would like to take a look at the format you will see that there is a correction factor that you can apply to adjust the FFT for gain differences between the reference (water) and sample. One subsequent revision was made to the template since it was uploaded so if it looks useful just give me an email and I can send you the latest edition.


Product Spotlight

IntraPhase Athena Phased Array System

The Athena Phased Array system, manufactured by WesDyne NDE Products & Technology, consists of a pha
sed array acquisition system and PC running IntraSpect software. A PC is used to perform acquisition, analysis and storage of the data. System hardware is capable of operating up to four data sets with any combination of phased array or conventional UT probes. NOW AVAILABLE IN 64-64 CONFIGURATION.

NOVO Armor 15 & NOVO Armor 22

The Armor Kit Contains the NOVO Armor, which provides additional mechanical protection to the NOVO 1
5WN & NOVO 22WN Detectors, the Armor Stand and a traveling soft cover. - Newest shock absorbent technology case - Water resistant design - Supports wired & wireless communication - Multiple positioning options - Tripod connection using the Built-in 1/4” threads - Simple Detector battery replacement

Immersion systems

ScanMaster ultrasonic immersion systems are designed for high throughput, multi shift operation in a
n industrial or lab environment. These fully integrated systems provide various scanning configurations and incorporate conventional and phased arrays technologies to support diverse applications, such as inspection of disks, bars, shafts, billets and plates. All of ScanMaster immersion systems are built from high accuracy scanning frames allowing for scanning of complex parts and include a multi-channel ultrasonic instrument with exceptional performance. The systems are approved by all major manufacturers for C-scan inspection of jet engine forged discs. Together with a comprehensive set of software modules these flexible series of systems provide the customer with the best price performance solutions.


NDTkit RT, TESTIA's Digital Radiography software The NDTkit product line software for X-ray analysi
s. NDTkit RT is a software benefiting from the Ultis kernel which is dedicated to radiographic image analysis. It offers a set of tools and filtering processes to assist RT operators in finding relevant flaws.

We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
this is debug window