130+ Gas Calibrations Including Pure and Mixed Gases. Response Time of 50 to 100 ms Typical. Pressure, Temperature, and Mass Flow Simultaneously Displayed. Easy-to-Use Pushbutton Interface. NIST Traceability Standard. Full Scale Ranges from 0.5 SCCM to 500 SLM. Turndown Ratio of 200:1. Position Insensitive. ±0.8% Reading Accuracy. RS232 Standard. Custom Live Gas Blend Programming. Store Up to 20 User Defined Gas Blends. More
The FMA-LP2600A Series mass flow controllers use the principle of differential pressure within a laminar flow field to determine and control mass flow rate. A laminar flow element (LFE) inside the meter forces the gas into laminar (streamlined) flow. Inside this region, the Poiseuille equation dictates that the volumetric flow rate be linearly related to the pressure drop. A differential pressure sensor is used to measure the pressure drop along a fixed distance of the LFE. This, along with the viscosity of the gas, is used to accurately determine the volumetric flow rate. Separate absolute temperature and pressure sensors are incorporated and correct the volumetric flow rate to a set of standard conditions. This standardized flow rate is commonly called the mass flow rate and is reported in units such as standard cubic centimeters per minute (SCCM) or standard liters per minute (SLM).
The controller uses a true proportional valve coupled to the flow body to control flow using the integral PID loop controller. Standard units include a 0 to 5V output (4 to 20 mA optional) and RS232 communications. The gas-select feature and the setpoints can be adjusted from the front keypad or via RS232 communications. Volumetric flow, mass flow, absolute pressure, and temperature can all be viewed or recorded through the RS232 connection. It is also possible to multi-drop up to 26 units on the same serial connection to a distance of 46 m (150').
Accuracy: ±(0.8% of reading + 0.2% FS)
Repeatability: ±0.2% FS
Turndown Ratio: 200:1
Control Response Time: 100 ms
Input Control Signal: 0 to 5 Vdc, RS232
Output Signal: 0 to 5 Vdc, RS232
Optional Input/Outputs: 4 to 20 mA, 0 to 10 Vdc
Operating Temperature: -10 to 50°C (14 to 122°F)
Zero Shift: 0.02%/ATM FS/°C
Span Shift: 0.02%/ATM FS/°C
Humidity Range: 0 to 100% RH, non-condensing
Excess Flow Rate: 2.4% FS
Wetted Materials: Standard: 303 and 302 SS, FKM, silicone RTV (rubber), glass-reinforced nylon, aluminum, brass, 410 SS, silicone, glass; >250 SLM: 416 SS and nickel replace brass; -LSS (Option):316LSS, 303SS, 430FRSS, Perfluoroelastomer standard, FKM, EPDM, Buna, Neoprene Maximum Pressure: 50 psig
To Use in Volumetric Mode: Near atmosphere, 15 psig recommended maximum. Volumetric flow meters and controllers not certified for accuracy at mass flow rates above the rated flow range of the meter. They are designed for near atmospheric pressure conditions only. The recommended maximum operating pressure is 15 psig
Supply Current: 0.250 A for 20 SLM and under; 0.75 A for 50 SLM and above (typical)
Supply Voltage: 15 to 30 Vdc for units 2 SLM and smaller; 24 to 30 Vdc for units 5 SLM and larger
Electrical Connections: 8-pin circular mini DIN
Complete informations can be found in the spec sheet (PDF), see the "Download" section.
A thermal mass flow meter measures the flow rate of gas mass based on the convective heat transfer of a heated surface to the flowing fluid. The components of a basic thermal mass flow meter include two temperature sensors with an electric heater between them. The heater can protrude into the fluid stream or can be external to the pipe.
In the past, mass flow was often calculated from the outputs of a volumetric flow meter and a densitometer. Density was either directly measured, or was calculated using the outputs of process temperature and pressure transmitters...
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