Recalibration Tool – SFC5XXX / SFM5XXX – Mass Flow Controller / Meter

Software Installation

1.1. SFC5XXX Recalibration Tool

Double-click the SFC5xxx_RecalibrationTool_Vx_xx.msi file to start the installer and follow the onscreen instructions.

The installer window displays a welcome message for the "SFC5xxx Recalibration Tool" and prompts the user to click 'Next' to continue. It includes a warning that the program is protected by copyright law.

Note: This software requires Microsoft .Net Framework 3.5. On most computers with Windows XP or newer this software should be pre-installed. If not, you can download it from the Microsoft website.

1.2. Virtual COM Port Driver

• Plug the RS485-to-USB adapter cable into the computer and wait for the automatic driver installation.
• If automatic installation does not take place, you have to do this manually. The Virtual Com Port (VCP) driver can be downloaded here (be sure to choose the correct version: 64/32 bit operation system): http://www.ftdichip.com/Drivers/VCP.htm

Software Manual

2.1. Start Recalibration Tool

Navigate through the Start Menu: Start → All Programs → Sensirion AG → SFC5xxx Recalibration Tool.

2.2. Connect to the Device

Ensure the Mass Flow Controller (MFC) is connected to the computer and powered on.

• Select the COM-Port/USB-Serial-Port that is connected to the Mass Flow Controller.
• Set an appropriate baud rate (default is 115200) and RS485 address (default value is 0).
• Click "Open".

Write down your settings if you have changed the connection parameters (refer to the relevant chapter for details).

Baudrate: .................................. Address: ..................................

The "SFC5xxx Recalibration Tool" window displays connection status. Key information includes System Information (Product Type, Product Name, Article Code, Serial Number, Version), Communication Interface (SHDLC) with Baudrate and Device Address, and a section for Active Calibration details. It also lists "Available Flow Calibrations" with Gas, Range, Gas ID, Location in Calibration Memory, Initial Calibration date/company/temperature/accuracy, and Last Recalibration date/company/temperature/accuracy.

2.3. Main Window

2.3.1. Select Calibration

After successfully connecting to the MFC, a list of calibrations will be displayed. The active calibration is highlighted in red. If multiple calibrations are stored, non-active ones appear in green, and unused fields are grey.

Above the list of calibrations, system information from the MFC is shown. On the right side, details about the currently activated calibration are presented.

To select an appropriate gas calibration from the "Available Flow Calibrations" list, right-click on the desired calibration and choose "Load Calibration".

2.3.2. Change Baud Rate / Device Address

The "Communication Interface (SHDLC)" section allows modification of the Baudrate via a dropdown menu and the Device Address via an input field. A "Change Address" button is available.

• To change the baud rate, select a new rate from the dropdown list. You will be prompted to confirm the change by clicking "Yes".
• To change the address, enter a new address between 0 and 254 in the address field and click "Change Address".

Note: The new baud rate and address settings will persist after a device reset or power down. They are required for future connections. It is recommended to record these settings.

2.4. Menu

2.4.1. Device: Get Device Error State

The SFC5xxx features an internal error status register. Access this information by selecting the menu item Device → Get Device Error State.

The "Device Error State" window lists various flags, their status (OK or ERROR), and a description. For example, Flag 0 indicates "System booted normally" (OK), while Flag 10 might indicate "Gas pressure is too small for given setpoint" (ERROR).

If the gas supply pressure drops or the MFC cannot reach the setpoint, the corresponding error status in the "Device Error State" list will turn red.

2.4.2. Reset

A device reset can be performed by selecting the menu item Device → Reset. This function is equivalent to a power cycle.

2.4.3. Device → Factory Reset

Selecting Device → Factory Reset will revert all settings to their factory defaults. Gas-specific settings, including calibrations, remain unaffected.

2.4.4. Device → Firmware Update

To update the device's firmware, navigate to Device → Firmware Update.

In the "Firmware Update" dialog, click "Browse" to select the firmware file (*.hex), then click "Update". Do not disconnect the device during the update process.

Note: If the update process is interrupted, a final attempt can be made by returning to the firmware update dialog, selecting the firmware file, checking the "Emergency Update" box, and clicking "Update".

Caution: Ensure the correct firmware is loaded, as the emergency update does not verify compatibility. Loading incorrect firmware may render the device unrecoverable.

2.4.5. Device → Advanced Settings/Tools → User Defined Medium Unit

This feature allows you to define custom units for setting the setpoint and reading the current flow. When setting a setpoint or reading flow values, you can select the "User Defined Medium Unit" scaling.

The "User Defined Medium Unit" dialog explains the scaling options: Normalized [0...1], Physical (Calibration Unit) [0... Fullscale @ Calibration Unit], and User Defined Medium Unit [0... Fullscale @ User Defined Medium Unit]. Users can input a custom unit name (e.g., "Percent %") and define its range.

2.4.6. Device → Advanced Settings/Tools → Controller Gain

The "User Gain" setting allows adjustment of the controller's speed.

The "Flow Controller User Gain" dialog explains that "User Gain" is a global, additional gain factor applied to all calibrations, stored in non-volatile memory. The default value is 1.0. Lower values result in a smoother, more stable controller, while higher values increase speed but risk instability or oscillation. This parameter is global and persists through resets.

2.4.7. Device → Advanced Settings/Tools → Gas Recognition Tool

The "Gas Recognition Tool" verifies if an activated gas calibration matches the gas in the line. This is a safety feature to prevent incorrect operation due to user error.

The "Gas Recognition Tool" dialog measures the gas's heat conductivity and compares it to a reference value from the loaded calibration. It displays fields for "Reference heat conductivity [Ticks]", "Measured heat conductivity [Ticks]", and "Tolerance +/- [Ticks]". A "Measure" button initiates the check, and the tool indicates "Gas OK!" if the measured value is within the specified tolerance.

2.4.8. Device → Advanced Settings/Tools → Sensor Temperature

This function displays the chip temperature of the flow sensor.

The "Sensor Temperature" dialog shows the current "Sensor Temperature" (e.g., 26.2°C) and provides "Read OK" and "Close" buttons.

2.5. Create New Calibration

New gas calibrations can be created based on existing calibrations for similar gases.

• To open the "Create new Calibration" window, right-click on an empty, grey calibration field in the main window and select "Create new Calibration" from the context menu.
• Select an existing calibration with similar gas characteristics from the dropdown menu.

The "Create new Calibration" dialog allows input of calibration metadata. Fields include "Gas and Range" (Gas ID, Gas Name, Fullscale Flow, Unit Encoding), "Initial Calibration" (Company, Operator, Temperature, Inlet Pressure, Accuracy), "Calibrated with process Gas" checkbox, "Differential Pressure", "Accuracy (% of FS)", and "Date and Time" (Year, Month, Day, Hour, Minute) with options to set to "Now" or "Invalidate". After entering the metadata and clicking "OK", a recalibration process can be initiated.

2.6. Perform a Recalibration

Before starting recalibration, ensure the desired calibration is activated (highlighted in red). If not, right-click the calibration field and select "Load Calibration" from the context menu.

To open the "Flow Recalibration" window, right-click the active (red) calibration field and choose "Recalibrate" from the context menu. The recalibration window will then appear.

2.6.1. Recalibration Window

The "Flow Recalibration" window displays "Calibration Information" (Gas ID, Gas Name, Fullscale Flow, Medium Unit, Location in Flash) and a graph showing "Sampling Points" with axes for "Flow from Sensor" and "Corrected Flow". It also includes "Recalibration Conditions" (Company, Operator, Temperature, Inlet Pressure, Accuracy, Diff. Pressure, Calibrated with process Gas, Date and Time) and "Current Setpoint and Measured Flow" (Setpoint, Measured Flow). Buttons are provided for "Setpoint MFC Setpoint", "Flow Reference", "Flow Value Scaling", "Write Data to Device and enable Correction", and "Close". The status "Flow correction disabled, enter Samples" is shown.

This tool enables correction of sensor readings that may have become inaccurate due to environmental changes or aging, using an additional lookup table.

2.6.2. Recalibration Metadata

The top-left portion of the "Flow Recalibration" window is used to enter metadata for the recalibration. This includes "Recalibration Conditions" such as Company, Operator, Temperature, Inlet Pressure, Accuracy, Differential Pressure, and Date/Time, along with a "Calibrated with process Gas" checkbox.

2.6.3. Physical/Normalized Flow Values

Choose the desired scaling for the flow values when filling the lookup table:

• Physical: Uses the physical unit from the initial calibration (e.g., 200 ml/min).
• Normalized: Uses values from 0 to 1, where 1 corresponds to full-scale.

2.6.4. Fill Lookup Table

Enter a series of setpoints into the "MFC Setpoints" column of the green table.

It is crucial that the process gas is connected to the MFC and the entire system, including the reference flow meter, is purged with it.

Once a setpoint's checkbox is selected, the MFC flow is adjusted to that value. Measure the actual flow using a reference flow meter.

A schematic illustrates the setup: "Process Gas" flows into an "MFC" (Mass Flow Controller), which is connected to an "MFM Reference" (Mass Flow Meter Reference).

Enter the measured reference reading in the "Flow Reference" column. Repeat these steps for all setpoints (up to 31 points).

After completing the lookup table, click the "Write Data to Device and enable Correction" button.

2.6.5. Verify Lookup Table

Important: For accurate recalibration, include the measured reference flow (offset) at the 0 setpoint of the MFC in the lookup table.

For recalibrating a mass flow meter (MFM), input the MFM flow reading in the left column (instead of the MFC setpoint) and the flow reference measurements in the right column.

The "Sampling Points" graph now shows "Flow correction enabled". The flow correction can be verified by re-selecting the setpoints. The mass flow controller and reference flow meter readings should now correspond to the selected setpoint.

• If no setpoint is selected, the setpoint defaults to zero, and the valve closes independently of the measured flow and correction.
• If deviations are detected, the recalibration procedure must be repeated.
• If the results are satisfactory, the recalibration is complete. Close the window using the "Close" button.

2.7. Edit Calibration Metadata

To open the "Edit Calibration Metadata" window, right-click on a calibration field in the main window and select "Edit Calibration Metadata" from the context menu.

This window allows modification of the metadata for a given calibration. It displays fields such as Gas ID, Gas Name, Fullscale Flow, Unit Encoding, Initial Calibration details (Company, Operator, Temperature, Inlet Pressure, Accuracy), Calibrated with process Gas status, Differential Pressure, Accuracy (% of FS), and Date and Time.

Important Notices

Warning, Personal Injury

Do not use this product as safety or emergency stop devices or in any other application where failure of the product could result in personal injury. Do not use this product for applications other than its intended and authorized use. Before installing, handling, using or servicing this product, please consult the data sheet and application notes. Failure to comply with these instructions could result in death or serious injury.

If the Buyer shall purchase or use SENSIRION products for any unintended or unauthorized application, Buyer shall defend, indemnify and hold harmless SENSIRION and its officers, employees, subsidiaries, affiliates and distributors against all claims, costs, damages and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if SENSIRION shall be allegedly negligent with respect to the design or the manufacture of the product.

ESD Precautions

The inherent design of this component causes it to be sensitive to electrostatic discharge (ESD). To prevent ESD-induced damage and/or degradation, take customary and statutory ESD precautions when handling this product. See application note "ESD, Latch up and EMC" for more information.

Warranty

SENSIRION warrants solely to the original purchaser of this product for a period of 12 months (one year) from the date of delivery that this product shall be of the quality, material and workmanship defined in SENSIRION's published specifications of the product. Within such period, if proven to be defective, SENSIRION shall repair and/or replace this product, in SENSIRION's discretion, free of charge to the Buyer, provided that:

• Notice in writing describing the defects shall be given to SENSIRION within fourteen (14) days after their appearance.
• Such defects shall be found, to SENSIRION's reasonable satisfaction, to have arisen from SENSIRION's faulty design, material, or workmanship.
• The defective product shall be returned to SENSIRION's factory at the Buyer's expense.
• The warranty period for any repaired or replaced product shall be limited to the unexpired portion of the original period.

This warranty does not apply to any equipment which has not been installed and used within the specifications recommended by SENSIRION for the intended and proper use of the equipment. EXCEPT FOR THE WARRANTIES EXPRESSLY SET FORTH HEREIN, SENSIRION MAKES NO WARRANTIES, EITHER EXPRESS OR IMPLIED, WITH RESPECT TO THE PRODUCT. ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE EXPRESSLY EXCLUDED AND DECLINED.

SENSIRION is only liable for defects of this product arising under the conditions of operation provided for in the data sheet and proper use of the goods. SENSIRION explicitly disclaims all warranties, express or implied, for any period during which the goods are operated or stored not in accordance with the technical specifications.

SENSIRION does not assume any liability arising out of any application or use of any product or circuit and specifically disclaims any and all liability, including without limitation consequential or incidental damages. All operating parameters, including without limitation recommended parameters, must be validated for each customer's applications by customer's technical experts. Recommended parameters can and do vary in different applications.

SENSIRION reserves the right, without further notice, (i) to change the product specifications and/or the information in this document and (ii) to improve reliability, functions and design of this product.

Copyright © 2021, by SENSIRION. CMOSens® is a trademark of Sensirion. All rights reserved.

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