Sierra Instruments” Cal=Trak XL primary standard gas flow calibrator is designed for high flows up to 500 SLPM. The calibrator is a good fit for calibration of gas measuring instruments, including mass flowmeters and controllers and offers accuracy of +/- 0.25 percent of reading. The dimensionally based primary accuracy of the device is backed by a rigorous uncertainty analysis. At 24″W x 30″H x 12″D, the calibrator can fit on any laboratory bench. It can be used in the manufacture, inspection, validation and recalibration of mass flow controllers, flowmeters and other varieties of flow equipment with flowrates too high for common primary standard devices. In either manual or automatic operation, the calibrator measures, displays and outputs the flow of gas, either in mass or volumetric units. The menu-driven configuration allows end-users to customize the calibrator to fit changing needs. The single integrated piston chamber of the calibrator can measure flows from 5 SLPM to 500 SLPM, over a 100-to-1 range. The Cal=Trak family of products provides primary NIST traceability, is manufactured under ISO 17025 certification, and is CE approved.