Volumetric glassware complies with Class A tolerance requirements of ASTM E 288 and NIST Circular 434; it is calibrated before first use and
recalibrated regularly in accordance with ASTM E 542 and NIST Procedure NBSIR 74-461. Balances are calibrated regularly with weights certified
traceable to the NIST national mass standard. Thermometers and temperature probes are calibrated before first use and recalibrated regularly with a
thermometer traceable to NIST standards. All products are prepared according to master documents that assure manufacture according to validated
methods. Batch records document raw material traceability and production and testing history for each lot manufactured.