70A-4

Overview

The Omega 70A-4 is a component within the Omega FMA7400/7500 series of thermal mass flow meters and controllers. This series utilizes a corrosion-resistant Hastelloy C-22 sensor to achieve high accuracy and reliability in gas flow measurement and control applications. The system features a programmable full-scale range with a 50:1 turndown ratio and includes an RS485 communication interface as standard. It offers fast response times of less than one second and supports in-process programming for multiple native gas calibrations. The unit is available with elastomer or metal seals and can be configured with 316 SS VCR fittings, ensuring integrity for challenging process gases.

Feature Summary

• Utilizes a corrosion-resistant Hastelloy C-22 sensor for durable long-term operation
• Features a database built on thousands of native gas runs to account for thermal and physical differences among gases
• Provides fast response time with settling time of less than one second
• Supports in-process programming for flexible gas type changes and re-ranging

Applications

• Chemical Vapor Deposition (CVD) processes
• Solar manufacturing processes
• Applications requiring frequent gas type changes
• Demanding gas flow measurement and control environments

Procurement Notes

Verify that the specific part number corresponds to the correct seal type (elastomer or metal) and fitting configuration required for your system. Confirm the native gas calibration reference matches your application needs, as the device relies on a database of native gas runs for accuracy. Ensure compatibility with the RS485 communication protocol if integration into an existing control network is planned. Check for availability of the 316 SS VCR fitting option if leak integrity for challenging process gases is critical.

Selection Notes

Select this model when high flexibility across multiple gas types is required without sacrificing accuracy due to viscosity and density differences. The 50:1 turndown ratio makes it suitable for applications with varying flow rates. Consider the Hastelloy C-22 sensor material for corrosive environments. The fast response time is advantageous for dynamic control loops. Verify that the standard RS485 interface meets your data logging or control system requirements.

Part Context

The 70A-4 is part of the Omega FMA7400/7500 series, designed to overcome limitations of traditional thermal mass flow units. Unlike simple correction factor models, this series uses a comprehensive database to handle complex gas properties. The series is engineered for customers needing to change gas types frequently or re-range while preserving measurement accuracy. It represents a robust solution for industrial gas flow management where reliability and precision are paramount.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. When replacing legacy thermal mass flow units, ensure the new device supports the necessary native gas corrections for your specific application gases to maintain accuracy.