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[MW:646] Re: Hardness by Equotip

By Materials & Welding
I am not agreeing with point 2 of Mr. Venugopal. At lower thickness [lessthan 10mm] we observed erratic readings. We observed this when checking hardness of attachment welds [This may be due to transfer of some amount rebound energy to the piece]. For more accurate results lower thickness pieces should be attached firmly to higher thickness pieces[Good surface contact is essential] before taking the reading
 
regards
 
SRSreddy
Aramco

 
On 3/2/08, juttada venugopal <jamsvenu@gmail.com> wrote:
Dear Reddy,
 

Equotip is digital based, unlike Poldy which is mechanical based.

(1) This needs the surface to be smooth, so that rebound shall be proper for its analysis.

(2) The rebound ball is few grams so thickness of the part shall not be an essential criterion. There is facility for angle setting in this instrument, 0deg  i.e., is hitting the targets vertically down, and other angle hitting facility exists

 (3) Equotip is supplied with thick round calibration block, valves on it are mentioned to match with for calibration purpose.

 (4) These are commonly used in maintenance sections of the plants. It only gives the valves of the hardness, so hope no implications of restriction of any codes prevails.  

 

Hope I have answered your questions.

 

Regards,
 
Venu
Singapore
================================================================
 
On Sun, Mar 2, 2008 at 5:26 PM, tamma reddy <tsr_52@yahoo.co.in> wrote:
Dear Friends,
 
Can any one through light on the following queries of digital hardness tester (Eqotip/TIME Group TH 160, HLN-11A/Krautkramer etc.)
 
1. Can weld joint hardness check up with rebound test principle
2. what is the minimum thickness of test specimen required for hardness check with above equipment (working on Rebound principle)
3. What are the calibration requirement of above instruments
4. Are they supported by any project construction codes/ standards
 
Regards,

T S Reddy
Jamnagar

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