SevenStar D07-19BM Thermal Mass Flow Meter

Overview

The SevenStar D07-19BM is a precision thermal mass flow meter engineered for real-time, direct measurement of gas mass flow rate without requiring pressure or temperature compensation. Based on the principle of constant-temperature anemometry (CTA), it employs a micro-machined sensor chip with heated and unheated platinum resistance elements embedded in a stainless-steel flow channel. As gas flows across the sensor, convective heat transfer alters the temperature differential between the elements—proportional to the mass flow rate of the gas. This method inherently measures mass flow (in standard cubic centimeters per minute, SCCM, or standard liters per minute, SLM), referenced to NIST-traceable standard conditions (0 °C, 101.325 kPa), eliminating dependency on gas density variations caused by ambient fluctuations. Designed for integration into process-critical environments—including semiconductor tooling, vacuum deposition systems, analytical instrumentation, and controlled atmosphere furnaces—the D07-19BM delivers stable, repeatable output under dynamic flow conditions.

Key Features

• High-accuracy thermal sensing architecture with ±1% F.S. accuracy for full-scale ranges ≤10 SLM and ±2% F.S. for higher ranges, validated against nitrogen calibration gas
• Fast dynamic response (≤2 seconds t₉₀) suitable for closed-loop gas dosing and pulsed-flow applications
• Ruggedized stainless-steel wetted path with multiple sealing material options—FKM (fluoroelastomer), PTFE, and CR—to ensure chemical compatibility across aggressive process gases (e.g., NH₃, Cl₂, SiH₄, O₂, Ar)
• Standard DB15 male electrical interface compliant with SEMI E10 and industrial I/O conventions; supports analog voltage output (0–5.00 V DC) scaled linearly to flow rate
• Wide operating range: 5 SCCM to 30 SLM (N₂-equivalent), with controllable setpoint from 2% to 100% of full scale
• Robust mechanical design rated for up to 10 MPa burst pressure and leak-tight performance (<1×10⁻⁹ SCCS He), enabling use in high-integrity vacuum and ultra-high-purity gas delivery systems
• CE-marked for electromagnetic compatibility (EMC), ensuring reliable operation in electrically noisy manufacturing environments

Sample Compatibility & Compliance

The D07-19BM is calibrated using nitrogen as the reference gas, with flow values traceable to national standards. For non-N₂ gases, optional gas-specific correction factors (GCFs) may be applied via external scaling or integrated firmware mapping—subject to validation per ISO 14040 and ASTM D7213 protocols. Its wetted materials meet USP Class VI biocompatibility requirements for pharmaceutical-grade gas handling and conform to FDA 21 CFR Part 11 data integrity guidelines when paired with compliant control software. The device complies with ISO 9001-certified manufacturing practices and supports GLP/GMP audit trails when deployed with validated SCADA or PLC-based monitoring systems.

Software & Data Management

While the D07-19BM operates as a stand-alone analog flow sensor, its 0–5 V output is fully compatible with third-party data acquisition systems (e.g., National Instruments DAQmx, Keysight PathWave, or Beckhoff TwinCAT). For system-level integration, SevenStar provides optional configuration utilities supporting RS-485 Modbus RTU communication (via add-on module), enabling remote zero calibration, span adjustment, and real-time diagnostics. All analog outputs are designed for seamless connection to PID controllers and distributed control systems (DCS), supporting continuous logging with timestamped metadata in accordance with 21 CFR Part 11 electronic record requirements when implemented within a validated environment.

Applications

• Semiconductor fabrication: Precise dopant and etchant gas delivery in CVD, PECVD, and ALD tools
• Vacuum coating systems: Reactive gas metering for sputtering and ion plating processes
• Pharmaceutical manufacturing: Inert gas purging, fluidized-bed drying, and lyophilization atmosphere control
• Research laboratories: Gas blending for catalytic studies, fuel cell testing, and environmental simulation chambers
• Optical fiber preform fabrication: Controlled helium and chlorine carrier gas flow during MCVD and OVD processes
• Calibration laboratories: Transfer standard for verifying secondary flow meters per ISO/IEC 17025 accreditation criteria

FAQ

Is the D07-19BM suitable for corrosive or reactive gases such as Cl₂ or NH₃?

Yes—when equipped with fluorocarbon (FKM) or PTFE seals and stainless-steel body, it is chemically resistant to most dry, non-condensing process gases. Consult the material compatibility chart before use with halogenated or strongly oxidizing species.
Can the device be recalibrated in-house?

Field zero calibration is supported via the analog offset adjustment procedure outlined in the operator manual; however, full-span recalibration requires certified N₂ gas and traceable pressure/temperature metrology, typically performed at authorized service centers.
Does it support digital communication protocols out of the box?

No—the base model features analog-only output. RS-485 Modbus RTU capability is available via an optional communication module installed externally or at time of order.
What is the maximum allowable upstream/downstream pressure differential?

The specified maximum working pressure drop is <0.02 MPa (≈2 psi) across the sensor at full scale; exceeding this may affect linearity and long-term stability.
Is firmware upgradeability supported?

Firmware updates are available through SevenStar’s technical support portal and require a dedicated programming interface; revision history and validation documentation are provided for regulated industries.