Kelly Pneumatics, Inc. Digital Mass Flow Meter

The Digital Mass Flow Meter accurately measures and displays mass flow rate, volumetric flow rate, gas temperature, atmospheric pressure and gas pressure, for both Air and Oxygen. Unlike most flowmeters, the Digital Mass Flow Meter has a touch screen interface, offering immediate customization in seconds. This customization includes selecting the preferred units for each specification, including many standard units typical to scientific and engineering applications. For using a mixture of Air and Oxygen, the percentage of oxygen is adjustable. And unlike most flowmeters, the Digital Mass Flow Meter can automatically adjust for typical errors in flow calculation due to back pressures of up to 100 psig. The unit also has an optional output of 0-5 volts as a measure of flow rate, with an adjustable sample rate based on user preference, for use with an oscilloscope or volt meter. The Digital Mass Flow Meter uses four sensors to accurately measure pneumatic specifications. Three sensors are in direct contact with the flow path: an anemometer for mass flow, a thermistor for gas temperature and a gauge pressure transducer for gas/back pressure. The fourth sensor, an absolute pressure transducer, is contained within the unit and away from the flow path for atmospheric pressure. Using the readings from all four sensors, the mass flow is calculated using the current environmental and application conditions. This mass flow is than converted to volumetric flow based on the current density of the environment and back pressure in the system. Specifications Supported Media Air, Oxygen and Nitrogen Flow Range 0 to 300 SLPM of Air Flow Accuracy 2% of reading or 0.05 SLPM, whichever is greater, at 70 °F and 14.7 psia Flow Sample Rate 50 milliseconds Temperature Range 0 to 50 °C (0 to 122 °F) Accuracy ±1 °C (±1.8 °F) at flows >1 SLPM Atmospheric Pressure Range 15 to 115 kPa (2.17 to 16.68 psia) Atmospheric Pressure Accuracy ±1.5% F.S. Maximum Allowable Atm. Pressure 400 kPa (58.0 psia) Back Pressure Range 0 to 100 psig Back Pressure Accuracy ±3.0% of Reading Max Allowable Back Pressure 200 psig Port Sizes 3/8" Female NPT (Standard), 1/4" Female NPT, Male 22 MM Tapered, Female 22 MM Tapered, Male 22 MM Straight Power Requirements 120 VAC via wall adapter, converted to 9 vdc at 500 mA Operating Temperature 0 to 50 °C (0 to 122 °F) Touch Screen Interface 3.5" TFT LCD Resistive, Backlit, 320 x 480 pixel Analog Feedback Voltage 0 to 5 volts DC, 16 bit resolution