Description General description This proficiency testing sample is produced in accordance with ISO/IEC 17043:2010. All information regarding the use of this material can be found in the reporting packet supplied for each sample. Other Notes Proficiency testing samples are presented as single blind. No values for the samples are released until the testing period concludes. Values of analytes vary lot to lot. Proficiency Testing Schedule (2020-2021) Soils LPTP20-S1 January 29 - March 13, 2020 LPTP20-S2 April 8 - May 22, 2020 LPTP20-S3 July 22 - September 4, 2020 LPTP20-S4 October 7 - November 20, 2020 LPTP21-S1 January 27 - March 12, 2021 LPTP21-S3 July 21 - September 3, 2021 Quick-Turn Study - (non-scheduled proficiency test that is available at any time)