Product Overview

The Thermal Gas Flow Sensor NK330 Series is designed based on the thermal dispersion principle and adopts the constant temperature difference measurement method to accurately measure gas mass flow. Since it directly measures mass flow, the sensor does not require additional temperature or pressure compensation under normal operating conditions, helping simplify system integration.

The NK330 features a programmable digital menu, LCD display, stable measurement performance, and excellent vibration resistance. Its optimized sensor design also supports gas media containing small amounts of moisture, oil mist, or impurities, making it suitable for demanding industrial environments.

The sensor is maintenance-free, offers a wide measuring range, multiple output options, and supports a broad selection of industrial gas applications.

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Why Choose the Thermal Gas Flow Sensor NK330 ?

Selecting the right gas flow sensor is essential for improving process efficiency and equipment reliability. The NK330 Series offers several practical advantages:

• Direct mass flow measurement without additional temperature or pressure compensation
• Constant temperature difference thermal measurement for stable gas monitoring
• Suitable for various industrial gases, including compressed air and natural gas
• Designed for gas media containing limited moisture, oil mist, and impurities
• Fast response and reliable long-term operation
• Maintenance-free design with no moving mechanical parts
• Wide measuring range suitable for small and large pipelines
• Multiple communication and output options for PLC and automation systems
• LCD display with programmable parameters for convenient on-site operation

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Working Principle

The NK330 Series operates using the thermal dispersion principle.

A heated sensing element and a reference temperature sensor are installed inside the probe. As gas flows across the sensing element, heat is transferred from the heated sensor to the flowing medium. The electronic circuit maintains a constant temperature difference between the two sensors, and the power required to maintain this temperature difference is proportional to the gas mass flow.

This constant temperature difference method enables direct mass flow measurement without mechanical moving parts, providing stable performance and long service life.

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Product Features

• Thermal dispersion measurement using constant temperature difference technology
• Direct gas mass flow measurement
• No temperature or pressure compensation required under normal measurement conditions
• Digital programmable menu
• Stable measurement with excellent vibration resistance
• Suitable for gas containing moisture, oil mist, and impurities
• Maintenance-free design
• High measurement accuracy
• Long service life
• Wide turndown ratio
• Multiple engineering units available
• LCD display for convenient operation

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Product Applications

The NK330 Series is suitable for measuring a wide variety of industrial gases, including:

• Compressed air
• Natural gas
• Coal gas
• Liquefied gas
• Flare gas
• Hydrogen
• Argon
• Ammonia
• Other industrial gases
• Gas leakage monitoring

Typical industries include:

• Petroleum
• Chemical processing
• Electric power
• Metallurgy
• Electronics manufacturing
• HVAC systems
• Water treatment
• Food processing
• General industrial automation

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Technical Specifications

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Size chart

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Range table

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Selection Table

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Typical Application Example

In compressed air systems, stable flow monitoring helps operators detect abnormal consumption, leakage, and equipment operating conditions. The NK330 Series can be installed on the main air pipeline or branch lines to continuously monitor gas flow. Combined with PLC or SCADA systems through 4–20 mA or RS485 communication, operators can observe real-time gas consumption and optimize system efficiency.

Because the NK330 measures mass flow directly, it is well suited for industrial applications where operating conditions may change. The maintenance-free design also helps reduce routine service requirements and supports long-term operation.

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Frequently Asked Questions

What gases can the NK330 measure?

The sensor is suitable for compressed air, natural gas, coal gas, hydrogen, argon, ammonia, liquefied gas, flare gas, and other industrial gases.

Does the NK330 require regular maintenance?

No. The sensor has no moving mechanical parts and is designed for maintenance-free operation under normal working conditions.

Can the NK330 be connected to PLC systems?

Yes. It supports Pulse, 4–20 mA, RS485 (HART) communication, and optional relay outputs for industrial automation systems.

What installation types are available?

The NK330 is available in both inline and insertion versions to accommodate different pipe diameters and installation requirements.