Control samples are any type of well-known samples used to verify the correctness of the analyzes / tests. These control samples are fully known to the customer in terms of their type, values of certain parameters and values of their standard deviations and uncertainties. They can also be used as blind samples. Blind sample - a sample known by the submitter but submitted to an analyst in such a way that its identification as a check/control sample is unknown.
Control samples are used for laboratory control purposes to verify the validity of the test results in terms of their reliability.
PTS Bulgaria Ltd. offers control samples that are left over from a certain PT scheme. Each control sample shall be accompanied by a certificate stating the values of the relevant parameters as well as their standard deviations and standard uncertainties.
Available control samples:
|Type of the sample||Subject of PT scheme №||Parameter with known values of the result and its standard deviation and standard uncertainty||Code of the standard|
|Coarse aggregate||PTS 22/02||Resistance to wear - micro Deval coefficient||EN 1097-1:2011|
|Resistance to fragmentation - Los Angeles coefficient||EN 1097-2:2020, clause 5|
|Pre-dried particle density, ρp||EN 1097-6:2022, Annex А, clause А.4|
|Magnesium sulfate value||EN 1367-2:2009|
|Asphalt mixture||PTS 21/07||Bulk density||EN 12697-6:2020, Procedure В (item 9.3)|
|Maximum density||EN 12697-5:2018, Procedure А (item 9.2)|
|Bitumen||PTS 21/07||Penetration||EN 1426:2015|
|Softening point||EN 1427:2015|
|Flash point||EN ISO 2592:2017|
|Percentage of change in mass||EN 12607-1:2014|
|Percentage of retained penetration at 25 ℃||EN 12607-1:2014, EN 1426:2015|
|Change in ring and ball softening point||EN 12607-1:2014, EN 1427:2015|