SI-20FD High Accuracy Gas Mass Flow Controller

The SI-20FD high-accuracy mass flow controller boasts a measurement error of only ±0.5% of full scale, making it the preferred choice for measuring and controlling small flow rates of gas. It supports analog outputs of 0-5V, 4-20mA, and 1-5V, and digital outputs of RS232/485, MODBUS, and PROFIBUS protocols.

The superior accuracy of this series stems from its unique sensor probe. This sealed probe consists of two sensing elements: a velocity sensor and a temperature sensor. It automatically corrects for the effects of temperature and pressure changes.

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Features

Specifications

Model and measuring range:

High Accuracy Gas Mass Flow Controller Working Principle

The SI-20FD is a high-accuracy series of flow meters/controllers with a measurement error of only ±0.5% of full scale. This series’ superior accuracy stems from its unique sensor probe. This sealed probe consists of two sensing elements—a velocity sensor and a temperature sensor—that automatically correct for the effects of temperature and pressure variations.

The SI-20FD High Accuracy Gas Mass Flow Controller circuit heats the velocity sensor to a constant value above the gas/liquid temperature. It then measures the cooling effect on the gas flow rate.

The flow rate is calculated based on the principle that the electrical power consumed to maintain a constant temperature difference is proportional to the gas mass flow rate. Both sensors are standard-grade platinum resistance temperature detectors (RTDs) sealed within a 316 stainless steel housing.

Laboratory and Industrial Environment Applications

The SI-20FD High Accuracy Gas Mass Flow Controller has a measurement error of ±0.5% of full scale, sufficient to meet the needs of most customers. It can be used for various experiments in laboratories as well as in complex industrial environments.

It plays an important role in research and production in various fields such as semiconductor and integrated circuit industries, special materials science, chemical industry, petroleum industry, pharmaceuticals, environmental protection, and vacuum systems.

Typical applications include:

Electronic process equipment, such as diffusion, epitaxy, CVD, oxidation, plasma etching, sputtering, and ion implantation; and coating equipment, fiber optic melting, microreactors, gas mixing systems, capillary measurement, gas chromatographs, and other analytical instruments.

To adapt to complex industrial environments, some models also support IP67 dust and water resistance and IICT4 intrinsically safe explosion protection. In addition to standard analog input/output interfaces, it also supports 485/232 interfaces, and the communication protocol is the standard Modbus RTU protocol.

Gas Conversion Coefficient Usage Instructions

Sino-Inst mass flow controllers and mass flow meters are generally calibrated with N2 at the factory. In actual use, if other gases are being used, reading correction may be necessary. This is done by multiplying the flow rate displayed on the flow meter by the flow conversion coefficient.

For single-component gases, the conversion coefficient can be found in the coefficient conversion table.

For a multi-component gas (assuming it consists of n gases), calculate its conversion using the following formula:

Coefficient C: Basic Formula: C = 0.3106N/ρ(Cp)

Where:
ρ—density of the gas under standard conditions
Cp—specific heat at isobaric pressure of the gas
N—molecular composition coefficient of the gas (related to the components of the gas molecules, see the table below)

For a gas mixture: N = N1(ω1/ωT) + N2(ω2/ωT) + … + Nn (ωn /ωT)

Where:
ω1…ωn—flow rate of the corresponding gas
ωT—flow rate of the gas mixture
ρ¹…ρn—density of the corresponding gas under standard conditions (values ​​see the gas conversion coefficient table)
Cρ¹…Cρn—specific heat at isobaric pressure of the corresponding gas (values ​​see the gas conversion coefficient table)
N1…Nn —These are the molecular composition coefficients for the corresponding gases; values ​​can be found in the Gas Molecular Composition Coefficients Table.

Notes:

1) Standard conditions: Pressure—101325 Pa (760 mmHg), Temperature—273.15 K (0℃).

2) For parameters of gases not listed in the Gas Mass Flow Rate Conversion Coefficients Table, please consult Sino-Inst.

Gas Mass Flow Controller Gas Flow Conversion Factor

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Sino-Inst specializes in manufacturing gas/liquid mass flow meters and controllers. Designed according to customers’ specific operating conditions and needs, our products are widely used in various industries for the precise measurement and control of gas/liquid mass flow rates.

They play a vital role in research and production in numerous fields, including the semiconductor and integrated circuit industry, specialty materials science, chemical industry, petroleum industry, pharmaceuticals, environmental protection, and vacuum systems. If you require a customized High Accuracy Gas Mass Flow Controller, please feel free to contact our sales engineers!

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SI-20FD High Accuracy Gas Mass Flow Controller | Sino-Inst

The SI-20FD High Accuracy Gas Mass Flow Controller circuit heats the velocity sensor to a constant value above the gas/liquid temperature. It then measures the cooling effect on the gas flow rate.

Product SKU: SI-20FD

Product Brand: Sino-Inst

Product In-Stock: InStock