MFM 393 – Mass Flow Indicator Totaliser

Short description: A microcontroller-based mass flow computation unit that accepts 3 analog inputs (DP, Pressure, Temperature) to calculate and display mass flow rate with 8-digit totaliser, optional retransmission, and RS485 MODBUS RTU connectivity. Designed for mass flow monitoring and process automation.

Key Features

• Rugged, state-of-the-art microcontroller-based system.
• Dual functionality: instantaneous mass flow rate display and 8-digit totalising.
• Accepts three 4–20 mA inputs: DP (non-square rooted), Line Pressure, and Line Temperature.
• On-site configurable ranges for inputs and computed mass flow.
• User-programmable gain & bias for each input and calculated output.
• Retransmission output (optional) corresponding to mass flow rate (4–20 mA).
• Serial connectivity via RS485 with MODBUS RTU protocol (optional).
• Built-in 24 VDC, 100 mA excitation supply for powering external transmitters.
• Battery-backed RAM stores totaliser value and settings.
• LED indications for input selection and communication.
• Manual totaliser reset from password-protected PROG menu.

Technical Specifications

• Inputs: Three 4–20 mA DC (DP, Pressure, Temperature)
• Calculation: Mass Flow = (Input1 × Input2) / Input3
• Display: 7-segment LED; 5-digit for flow rate, 8-digit for totaliser
• Resolution: 4½ digit for flow rate
• Accuracy: ±0.3% of FS ±1 LSD (flow), ±2 counts (totaliser)
• Totaliser: 8-digit; resettable from password-protected menu
• Keyboard: 4-key tactile keypad
• Scaling: Flow rate and totaliser span scalable via keypad
• Excitation Supply: 24VDC, 100 mA for powering transmitters
• Retransmission (Optional): 4–20 mA retransmission corresponding to mass flow rate; max load 500 Ω
• Communication (Optional): RS485 with MODBUS RTU protocol
• Data Storage: Totaliser and settings in battery-backed RAM
• Indications: LEDs for input selection and communication
• Power Supply: 230 VAC or 110 VAC ±10%, single phase, 50 Hz (factory set)
• Connections: Screw-type connectors for supply, inputs, and outputs
• Mounting: Panel mount; Bezel: 96 × 96 mm (H × W); Depth: 150 mm; Cut-out: 92 × 92 mm

Support Videos

Downloads

• 📄 Product Manual (PDF)

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Call us at +91-20-24479210 or email scan@vsnl.com

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