Surface Profile Meter

Are you looking for an Optical Comparator? This is a visual inspection device.

This is just a wild guess to get us moving.

What is 50 nb?

50 nb means 50 mm Normal Bore.

Or 2" size pipe.

We are in speciality coating mfg. Prior to internal coating of pipes we sandblast it to prepare rogh surface for good adhesion of coating. For big pipes we can control / check the surface profile [By STD. SA 2 1/2 ]. but for small pipes i cannot get any handy instrument.

This is as far as I got, before being asked for money, to address your question.

NEAR WHITE METAL, NACE No. 2/SSPC-SP10 [link is to spec at TechStreet], SWEDISH Sa.2.5

1.1 This joint standard covers the requirements for nearwhite metal blast cleaning of uncoated or coated steel surfaces by the use of abrasives. These requirements include the end condition of the surface and materials and procedures necessary to achieve and verify the end condition.

1.2 The mandatory requirements are described in Sections 1 to 9. Section 10, "Comments," and Appendix A, "Explanatory Notes," are not mandatory requirements of this standard. 1.3 Information about the function of near-white metal blast cleaning is in Paragraph A1 of Appendix A. 1.4 Information about use of this standard in maintenance coating work is in Paragraph A2 of Appendix A.

I have emboldened the part that seems to pertain to your question.

If you require ideas on achieving this in small bores - please acquire the Standard and post the relevant sections.

thank you for reply.

But i need handy instrument for checking the quality of INTERNAL surface OF small dia. pipes.

I googled too much [as usual] but instruments are available for big curvatures.

You are not explaining what is is you want to measure

Checking what "quality of INTERNAL surface"

Choices range from expanding bore gauge, through internal micrometer, to surface finish, to roundness, to plug gauges, to laser bore, and on and on, to pits, inclusions, voids, thickness .....

It's like posting "how long is a piece of string?"

Please explain: small sizes @ 50 nb ???

And: do you need roughness or waviness or diameter or lengthwise measurements or all?

Roughness and short wavelength waviness: optical straylight

long wavelength waviness to geometry: optical triangulation, specialised interferometrs, specialised capacitive probes.

RHABE

50 nb means 50 mm Normal Bore.

Or 2" size pipe.