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Re: [MW:13902] RE: 13897] best portable hardness tester-digital

By Materials & Welding
Yes,  John is Right leading top clients not accepting, we too have Equo Tip.
At present we are using Foundrax, heavy, good sensor unit connected with PC. Its indentation units also bit heavy. For all subsea pressure equipment this one approved by customers Chevron, BP, FMC, Cameron, Total etc...
 
Regards,
S.SENTHILKUMAR
From: John Henning <jhenning@deltak.com>
To: materials-welding@googlegroups.com
Sent: Friday, 16 March 2012 6:02 PM
Subject: [MW:13901] RE: 13897] best portable hardness tester-digital

In my experience, there is no single "best" portable hardness tester.  Below are several I have worked with and their +'s from my experience:
 
EquoTip         (Leeb type)
+  small, light weight, user friendly, different indenters depending on application
-  needs correction for direction, operator sensitive, needs surface prep for repeatability,  will read significantly low if there is insufficient mass in direction of test
 
Krautkramer MIC10    (ultrasonic, resonant frequency type)
+  small, light weight, user friendly, indent virtually un-noticeable
-  very sensitive to surface prep adequate grinding required for repeatability, may not be useable in some close quarters applications, operator sensitive
 
RockMate
+  simulates standard Rockwell test, portable, user friendly, less sensitive to surface prep than EquoTip or MDC10, not particularly sensitive to operator
-  bulkier than EquoTip or MIC10, requires much larger foot print than EquoTip or MIC10, not for tight quarter use
 
The non-digital, brute force method, i.e. TeleBrineller, is still a valid method that you might want to consider. 
 
Myself, I would avoid the EquoTip (Leeb – falling ball) type.  I have too much experience with the mass effect to trust a value by this method unless the part is truly massive,  the indent orientation can put at least 6 inches (150mm) of material beneath the indenter, or the part is small enough with a flat enough area to be effectively "coupled" to a massive item.   Look at the size of calibration block that is required for  the Equotip – that thickness is required to obtain an accurate, repeatable values and is what one needs to obtain correct hardness values in the field.  EPRI and NUMARC in the 1980's did quite a bit of testing with the EquoTip and found it too read consistently and significantly low in almost all cases. 
 
The non-digital, brute force method, i.e. TeleBrineller, is still a valid method that you might want to consider. 
 
 
Good luck.
 
John A. Henning
Welding & Materials
 
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of pawan
Sent: Friday, March 16, 2012 7:20 AM
To: materials-welding@googlegroups.com
Subject: [MW:13897] best portable hardness tester-digital
 
Hi,
 
Pl. suggest best digital portable hardness tester (HRC) to check the weld metal hardness on 3layers pad.
 
T&R
Pawan tiwari
 
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