Proficiency Testing and Interlaboratory Cross Check Programs

2024 Cross-Check Program Schedule

The verification of analytical performance through a blind cross-check program, also known as a proficiency testing (PT) is an integral part of an effective quality assurance program. It is required by the ISO/IEC 17025 standard, ‘The general requirements for the competence of testing and calibration laboratories’ and the US DOD/DOE Consolidated Quality System Manual (QSM) for Environmental Laboratories.  The US Nuclear Regulatory Commission, Regulatory Guide, 4.15, recommends the use of cross-checks samples as an important independent check on methods used in a radiological monitoring program.  

In addition to ISO 17025, Eckert & Ziegler Analytics maintains accreditation to the ISO/IEC 17043:2010 standard, demonstrating technical competence in the field of Proficiency Testing Provider under a broad scope, covering solids, liquids, gasses and flowing materials.  We maintain traceability through a measurement assurance program, conducted according to ANSI N42.22 with a national metrology institute.

Two distinct-inter-laboratory cross-check programs are offered by Analytics. The Inter-laboratory Cross-Check Program for Nuclear Power Plant laboratories provides blind samples that simulate routine effluent samples. The Inter-laboratory Cross-Check Program for Environmental Measurements laboratories provides blind samples at environmental levels in water, milk, soil, simulated vegetation, air filters and charcoal cartridges. Each program provides quarterly, blind samples at concentrations that permit an evaluation of your analytical accuracy. The concentration of radionuclide covers a range that allows for reasonable counting statistics.


  • Samples can be used for the training and testing of personnel and procedures.
  • Interferences and activity levels can be varied to better test procedures and equipment.
  • Analytics' samples are carefully prepared from calibrated standards and shipped in stable forms, therefore the samples' activities are more accurately known.
  • Traceability is maintained through Analytics' participation in measurement assurance programs with NIST following ANSI N42.22.

Training, procedure testing and measurements assurance are all areas that benefit from Analytics' Inter-laboratory Cross-Check Programs.


  • Performance and technique evaluation
  • Technician qualification
  • Internal quality-control samples
  • Accuracy and precision evaluation
  • Evaluating sample-preparation procedures
  • Testing radiochemical procedures
  • Exploring new laboratory techniques
  • Qualifying computer software

Choose from:

USA / North and South America / Australia / China & Far East Asia


Eckert & Ziegler
Analytics, Inc.
1380 Seaboard Industrial Blvd.
Atlanta, GA 30318

Phone: +1 404 352 8677
Fax:     +1 404 352 2837

Europe / Africa / Middle East Asia / Japan

Eckert & Ziegler

Nuclitec GmbH
Gieselweg 1
38110 Braunschweig

Phone: +49 5307 932 0
Fax:     +49 5307 932 272



Eckert & Ziegler Isotope Products France
12 avenue des Tropiques
Hightec Sud - bâtiment B
91955 Courtaboeuf cedex
Phone: +33 1 64 86 22 22
Fax:     +33 1 69 86 10 65