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 -

732 views
Technical Discussions
Ehsan
Ehsan
06:11 Mar-09-2009
Circular shot current calculation

Dear All,
as per ASTM for circular shot NI=K/(L/D).
but i am not very clear at the time of calculating L/D for many parts Viz Crankshaft/Camshafts/spindles and other difficult geometry components.
your valuable responce are awaited.

Thanks

Ehsan

    
 
 
Michel Couture
NDT Inspector,
consultant, Canada, Joined Sep 2006, 821

Michel Couture

NDT Inspector,
consultant,
Canada,
Joined Sep 2006
821
15:49 Mar-09-2009
Re: Circular shot current calculation
In Reply to Ehsan at 06:11 Mar-09-2009 (Opening).

Ehsan,

Andreas brought a valid point. But one thing I would like to mention to all who do MT is the formulas given in ASTM E709 and E1444 are in my opinion only guidleine or starting point if you will. On factor we never really consider in our calculation is: "permeability".

For this reason, when I taught MT, I used to tell my students the calculations are only a starting point. I would always magnetised my parts using a lower amperage than what my calculation showed me. Always, verify with my pie gauge or QQI to ensure you are getting the proper magnetisation. You will be surprise at how low the amperage is compare to calculations. Other things to consider when doing MT is particle mobility and background.

One other thing, whenever you do MT, try to picture the part as being a straight piece of round stock. You were talking about a crackshaft, well how long would it be if it was straight?

Remember, always verify your magntisation with a QQI or pie gauge.

Cheerio's

I hope this will be of help.

    
 
 
Andreas
NDT Inspector, Specially in the oilfield
Tuboscope Vetco(Deutschland)Gmbh, Germany, Joined Oct 1999, 126

Andreas

NDT Inspector, Specially in the oilfield
Tuboscope Vetco(Deutschland)Gmbh,
Germany,
Joined Oct 1999
126
19:17 Mar-09-2009
Re: Circular shot current calculation
In Reply to Michel Couture at 15:49 Mar-09-2009 .

The E 709 eveen state that is only a guideline and you should verify the field by a "gausmeter" , correct would be a Tesla meter to use correct SI units.
I like the so called "Burmah-Castrol strip" , it shows you the magnitude and direction of the field.
If you see the three indication on the strip ,the field is 2.4 kA/m or greater (2 - 6 kA/m is required by EN specs).If not placed perpendicular (90° ) to the applied magnetic ,then no indication will be shown.

    
 
 

Product Spotlight

High Resolution Industrial CT System for Small/Medium Size Parts Inspection

The YXLON FF35 CT computed tomography system is designed to achieve extremely precise inspection res
...
ults for a wide range of applications. Available in a single or dual tube configuration, it is perfect for very small to medium size parts inspection in the automotive, electronics, aviation, and material science industries.
>

Mentor UT – Ultrasonic Phased Array Flaw Detector

With Mentor UT, you get an accessible and efficient inspection experience. Create user-defined menus
...
and workflows (“apps”) with GE’s desktop software Mentor Create to ensure consistency, even for the most complex inspections, every time. Mentor UT is the first UT device to easily allow wireless connectivity and live streaming, so you get second opinions when you need them most—in real-time.
>

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.
>

Varex Imaging Large Field of View (FOV) Digital Detector Arrays (DDAs)

A larger FOV DDA can reduce the space and volume of the X-ray inspection system on the factory floor
...
, enable faster scanning times, better throughput and better resolution images at a lower dose. Customers can also save time and money. With these benefits in mind, Varex Imaging has designed a family of large FOV detectors (4343HE, XRD 1611, 4343DX-I, 4343CT) for our industrial imaging customers.
>

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