I am looking for a calibration procedure to do in-house calibration of height gages, particularly the stack style like the Starrett Digi-Chek models. Can someone share a procedure with me?

I normally use GIDEP (Government Industry Data Exchange Program) procedures for such things. But their distribution is restricted. So if it is of any possible help, you might consider trying to join GIDEP. It's free, but your company has to "SOMEHOW" provide products or services to the U.S. government. If you in any may qualify, that would easily cover you.

The other option might be ASTM procedures. If you don't have any strict compliance requirements, could be someone could send you some instructions which you could convert into your own internal procedure. If that ends up the case, please feel free to send me an email offline with an example model, and I could try to get something for you.

Here is the procedure that I use in my lab.

1.0 PURPOSE
This work instruction defines the standard procedure for the calibration of height gages.

2.0 SCOPE
This instruction applies to all like height gages.

3.0 DEFINITIONS
NIST - National Institute of Standards & Technology

4.0 REFERENCE DOCUMENTS
Measuring & Test Equipment Calibration Record - F1101

5.0 PROCEDURE
CALIBRATION AND STANDARDIZATION
All standards used in calibration are traceable to the NIST.


EQUIPMENT REQUIRED
Lint-free cloth.
Gage Blocks
.0001 Indicator
Height Gage (other than the one being calibrated)
Soft brass brush
Calibration Record - Form F1101 or electronic record.
Parallel Bar

METHOD
1. The initial calibration is to be done by the manufacturer or outside lab. The calibration certificate from the manufacturer or outside lab is to become part of the permanent record.

2. Examine the height gage for obvious external damage or other signs of abuse or wear which may affect the accuracy or function of the instrument. Note this in the “as found” condition in calibration record.

3. Clean all surfaces to remove oil and/or any foreign material. Do not allow cleaning solution to enter the dial assembly or electronics if so equipped.

4. Verify that the height gage is in good working order: i.e. no sticking or binding in travel

5. Clean the bottom of the scriber holder. Clamp the parallel to the scriber holder.

6. Clean the bottom of both height gage bases. If necessary use an Arkansas stone to insure a smooth surface. Clean the surface plate with surface plate cleaner.

7. Clamp the indicator to the non-calibrating height gage.

8. With the parallel close to the surface plate, check the top of the parallel with the indicator to make sure it is parallel to the surface plate.

9. Raise the parallel to the top of the column and then indicate the top of the parallel to check square of the column to the base.

10. Remove the parallel and install the indicator.

11. Using gage blocks, check the height gage from the surface plate to its full height in increments of 2” inch. Double check at random heights to assure accurate measurements are being taken. Record the results in the calibration record.

12. If the height gage fails to pass calibration, try to determine the reason and repair if possible. If unable to repair then send to an outside lab for repair and calibration.

13. When finished put a light coating of oil on column to protect it from moisture.



ACCEPTANCE LIMITS
0-12” height gages will be within ± .001”, 0-18” height gages and 0-24” height gages will be within ± .002”


6.0 QUALITY RECORDS
Quality Record Name Storage Location Index method Retention

Hope this will help. Feel free to use this in whole or any part that applies to your lab.

:cool:

Thanks so much, this is very helpful. Just what I was looking for.

I'm looking for calibration instruction of micrometers, calipers, verniers, dial and digital indicators. Can somebody help me?