As a category of certified reference materials (CRMs), Standard Reference Materials (SRMs) are produced by the National Institute of Standards and Technology (NIST) to ensure that measurements from analytical instrumentation are reliable. Essentially, NIST Standard Reference Materials can act as calibration standards or serve as a control sample. Standard Reference Materials can provide evidence that results are accurate and your quality controls are functioning properly. This is through their metrological traceability and accountability for associated measurement uncertainty.
There is a price linked with Standard Reference Materials because of their required levels of testing. This expense is due to the strict sampling, assay techniques, and data analysis performed by NIST. If you intend to use Standard Reference Materials, especially as calibration standards, you need