Calibration Standards are an important part of the measuring system. Without this, the measuring meter is redundant. Trans Instruments makes its best efforts in adhering to strict standards of conformance to the National Institute of Standard Test Methods (NIST). These solutions are tested against instruments calibrated against certified standards. Each standard solution is made in soluble form, sealed and date coded to ensure the highest quality and accuracy when delivered. Never compromise with using power form standards which require mixing and handling.