Aalborg® Instruments has designed Direct reading flow tube scales exclusively for a specific gas or liquid at a given temperature and pressure valid only for the associated units of flow. Flow rates for a specified set of parameters are clearly indicated in specific engineering units, such as mL/min or scfh. NIST traceably calibrated for specific liquids and gases, these units are suited for OEM applications and processing industries. Direct reading scales are available for argon, carbon dioxide, helium, hydrogen, hydrogen chloride, methane, nitrous oxide, oxygen, and propane.