UKAS certificate of first calibration for 5xxE standard

Certificate established for a maximum of 3 parameters to be chosen from 7 parameters Ra, Rq, Rz, Rt, Rmax, Rp, Rv to be specified when ordering

In January 2015, the Rubert Calibration Laboratory received accreditation to International Laboratory Management Standard ISO 17025:2005 from The United Kingdom Accreditation Service (UKAS). In December 2019 Rubert were accredited against the new ISO 17025:2017 standard by UKAS. This makes it one of only two UK calibration laboratories that are UKAS accredited for measurements of surface texture parameters, and the uncertainties of 2% + 4 nm which we offer for measurements of Ra and Rq within the range 0 to 25 µm, are currently the lowest uncertainty values available from any UK calibration laboratory.

Rubert can provide UKAS Calibration Certificates for any roughness specimen or measurement standard, whether manufactured by Rubert or by any other manufacturer. (UKAS No. 4685)

Full details of the parameters and their corresponding Best Measurement Capabilities are shown in the table below

Measured Quantity	Range	Calibration and Measurement Capability (CMC) Expressed as an Expanded Uncertainty (k = 2)		Remarks
LENGTH
Surface texture measurement standards	ISO5436-1:2001 Types B, C and D(Ra, Rz, Rt, Rq, Rmax, Rp, Rv)			NOTES : The uncertainty quoted is for the distance separating the two parallel plane lines which just enclose the profile under consideration. All linear calibrations may be given in inch units.
	Peak to valley range	Ra, Rq	Rz, Rt, Rmax, Rp, Rv
	10 nm to 100 nm	2.0 % + 4 nm	3.0 % + 4 nm
	100 nm to 1.0 µm	2.0 % + 4 nm	3.0 % + 10 nm
	1.0 µm to 25.0 µm	2.0 % + 4 nm	3.0 % + 20 nm
	Notes:The specific characteristics of the standard being calibrated may significantly affect the estimate of the measurement uncertainty.	ExampleA calibration certificate might report on a measurement standard whose nominal values are Ra = 1 µm, Rz = 3.0 µm, thus: Ra = 1.01 µm +/- 0.0242 µm Rz = 3.20 µm +/- 0.116 µm

The schedule above means that Rubert is able to measure any roughness standard, whose total peak to valley roughness height is in the range 10 nm up to 25 µm, for any of the seven R-parameters quoted, and issue a traceable calibration certificate with statement of uncertainty for that roughness standard.

The exact method of measurement (often referred to as the measurement protocol) which we use, is chosen to be suitable to the type of specimen and also the specific needs of the customer. Usually this will consist of twelve measurements made over the specimen’s measuring area, at evenly-spaced locations subject to the absence of serious defects, followed by software evaluation of the roughness parameters. Wherever applicable, procedures and requirements set out in standards ISO 5436-1, ISO 12179 and ISO 25178-70 are followed.