How to calibrate Hardness Rockwell, Brinnell & Vickers Tester machine

[jhoniegudel]

We have Hardness Rockwell, Brinnell & Vickers Tester machine.
We still confused how to calibrate this equipment.
Does anyone have Calibration procedure???? (base on ISO)

thanks

jhonie gudel

[Benjamin28]

Typically we have these calibrated by an outside accreditted laboratory, who has the correct tools and expertise. We do however perform the routine operational checks (prior to use) which is perhaps what you're asking about?

Here is what we consider for operational checks:

Prior to test, verify that the test equipment is in good operating condition by performing and recording the prescribed Operational Checks. Verify that the test instruments carry a valid calibration sticker.

Operational check for the Brinell machine consists of:

4.3.1. Verify Brinell diameter measuring system
4.3.2. Verify condition of anvil
4.3.3. Verify condition of indenter
4.3.4. Verify hardness on certified test block for the applicable range to be used

Operational check for the Rockwell hardness testing machines consist of:

4.4.1. Balance depth-measuring device
4.4.2. Balance load cell
4.4.3. Verify condition of anvil
4.4.4. Verify condition of indenter
4.4.5. Verify hardness on a certified test block for the applicable range to be used


For the device calibration this is a guideline we follow to ensure the outside calibration company performs suitable calibrations.

BRINELL HARDNESS TESTING MACHINES

4.6. An NIST Traceable Load Cell or Proving Ring shall be used to verify Load applied over the range of the Testing Machine. A minimum of three readings shall be taken at each applicable load.

4.7. The Calibration Technician shall assist and supervise the Hardness Tester Calibration Technician and monitor all recorded data.

BRINELL HARDNESS OPTICAL SCANNING SYSTEM

4.8. The Brinell Hardness Optical Scanning system is verified by the Calibration Technician using calibrated WCG’s. These are calibrated using a stage micrometer with metric divisions of 0.01mm. Choose appropriate reference points in order to insure that the 0.01 mm divisions of the Stage Micrometer can be utilized for measurement. Record all measurements and deviations.

ROCKWELL HARDNESS TESTING MACHINES

4.9. The diamond indenter shall be free from surface defects (cracks, chips, pits, etc.) and polished to such an extent that no unpolished part of its surface makes contact with the test piece when the indenter penetrates to a depth of 0.3 mm for Rockwell hardness testing and 0.2 mm for Rockwell superficial hardness testing.

4.10. The Rockwell Testing Machine shall be verified by means of certified test blocks for multiple readings encompassing the ranges in which the machine is used. #### currently has two Rockwell Testing Machines; one is used for Standard Rockwell Testing and the other is used for Superficial Rockwell Testing.

4.11. For Standard Rockwell Testing, a minimum of six indentations shall be measured for each of the following ranges:
HRC: 60 - 68
HRC: 40 - 50
HRC: 23 - 30
HRA: 72 – 80
HRB: 80 – 90
4.12. For Superficial Rockwell Testing a minimum of six indentations shall be measured for each of the following ranges:
HR15N: 60 -70
HR30N: 70 - 80
HR45N: 65 - 75
HR30T: 60 - 70

Having an accreditted lab calibrate these testers will almost certainly be your best approach. For the operational checks you need to have an assortment of certified test blocks within the ranges of your testing activities.

Hope this helps.

[Hershal]

I agree with getting an accredited calibration lab to calibrate the machine.....but checking it is also a good idea.....

You should get certified blocks, and obtain a copy of ASTM E 18 (available through ASTM in the U.S.), and implement a check methodology between calibrations.

Hope this helps.

Hershal

[jhoniegudel]

Thanks to Benjamin & Hershal

In our company we have allready use Block refference for hardness tester verification. And we already verificated it. That is enough?
Our customer required for calibrating our hardness tester machine. Does anyone know where we can calibrated our hadness tester machine and can explain how this equipment calibrated?


jhoniegudel

[Benjamin28]

You can use any appropriately accreditted source for your calibrations.

http://www.instron.us/wa/services/ca...ab_wilson.aspx

This is one example. You'll want to ensure they are accreditted for hardness calibrations. How your calibrations are performed will depend on what type of equipment you're utilizing.

[micron master]

In Reply to Parent Post by jhoniegudel

Thanks to Benjamin & Hershal

In our company we have allready use Block refference for hardness tester verification. And we already verificated it. That is enough?
Our customer required for calibrating our hardness tester machine. Does anyone know where we can calibrated our hadness tester machine and can explain how this equipment calibrated?


jhoniegudel

Since the testers are in use, you will be performing "indirect verification" by using test blocks. You can find the procedure for this in either ASTM E-18, or ISO 6508-2.

Basically, for the ASTM method, you make 5 readings on three test blocks per scale, one from the low, mid, and high hardness ranges. You only need to verify the scales that you actually use. You may have an outside source do this, or you may do it yourself.

Please feel free to contact our distributor in Singapore, lau@noblelab.com. He can either help you himself or direct you to someone in Indonesia who is familiar with the procedure.