T-262.1 Densitometers shall be calibrated every 90 days…..
(a) A national standard step tablet or a step wedge calibration film, traceable to a national standard step tablet having at least 5 steps with densities 1.0 thru 4.0 shall be used.
The step wedge calibration film shall have been verified within the last year by comparison with a national standard step tablet unless……………
My questions are
National standard step tablet ,Is this something that can be purchased or is this something that only a lab would have access too.
And, If I purchase a Calibrated step tablet would this be considered a national standard step tablet and do I need to have this verified yearly (The step wedge calibration film shall have been verified within the last year by comparison with a national standard step tablet).
Any input on this would help
MDK