High Accuracy mass flow meter/flow controller

Performance and Operating Principle of SRK-20FD Micro gas flow meter

The SRK-20FD is a high-precision flow meter/controller with an exceptional measurement accuracy of ±0.5% of full scale. This superior accuracy is achieved through an advanced thermal mass flow sensing technology, incorporating a specialized dual-element sensor probe.
The sealed probe features two precision-engineered sensing elements: a velocity sensor and a temperature sensor, which work in tandem to automatically compensate for variations in temperature and pressure. The micro flow instrument’s circuit maintains the velocity sensor at a fixed temperature differential above the process gas temperature and continuously measures the heat dissipation caused by gas or air flow. The mass flow rate is determined based on the principle that the power required to sustain a constant temperature difference is directly proportional to the mass flow rate of the gas.
Both sensing elements are high-precision platinum resistance temperature detectors (RTDs), encapsulated within a 316 stainless steel housing to ensure long-term stability, corrosion resistance, and reliability in industrial applications.

Applications in Laboratories and Industrial Environments

The SRK-20FD series high-precision flow meter/controller delivers a ±0.5% full-scale accuracy, ensuring reliable performance for a wide range of laboratory experiments  (lab flow meter) and demanding industrial applications. Its precision and stability make it suitable for use in scientific research , process control, and fluid measurement applications across various sectors.
To withstand harsh industrial environments, select models in this series feature an IP67-rated dustproof and waterproof design, ensuring protection against contaminants and moisture ingress.
The SRK-20FD series micro thermal mass flow meter /flow controller supports standard analog input/output interfaces while also offering RS485/RS232 communication, utilizing the Modbus RTU protocol for seamless integration with industrial automation and control systems.

Key Features of the SRK-20FD Micro thermal mass Flow Meter/Controller

• High Accuracy: Measurement precision up to ±0.5% of full scale (F.S.)
• Excellent Repeatability: ±0.2% of F.S., ensuring consistent performance
• Rapid Response and Control: Fast reaction time with precise flow adjustments
• Intuitive Touchscreen Display: User-friendly operation and real-time monitoring
• Direct Mass Flow Measurement: No need for additional pressure or temperature compensation
• Automatic Temperature Compensation: Ensures stable and accurate readings under varying conditions
• Integrated PID Control: Enables real-time flow rate regulation and process automation
• Configurable Gas Medium Selection: Supports manual switching of measured gases,availbe for different type gas flow measurement, such as hydrocarbon gases ，HCL gas flowmeter，chlorine gas (Cl2) ,AR gas,H2 flow meter, HBr,He,N2 flow meter,NH3,O2,SiH4 GAS , SF6 gas flow measurement and so on.
• Advanced Thermal Mass Flow Sensing: Delivers high accuracy (0.5% ) with ultra-fast response (within 0.2 s response time)
• Optimized Flow Path Design: Tubular flow diversion structure minimizes clogging risks
• Versatile Pipeline Compatibility: Suitable for both high-pressure flow meter and low-pressure flow meter applications
• Minimal Warm-up Time & High Stability: Short preheating duration, low zero drift, and enhanced reliability

Technical Specifications of Micro mass flow meter for gas

High precision quality flow controller		High precision mass flow meter
Technical indicators
Range range	2S CCM~6000 SLM	2SCCM~6000 SLM
Measurement and control range	Controller valve control range 50:1	Flow metering ratio 100:1
Accuracy	±0.5%F.S(Full range)
linear	±0.25%F.S
Repetitive accuracy	±0.2%F.S
response time	<0.2s	<0.1s
temperature coefficient	±0.025%F.S/℃
working temperature	0~50℃
Preheating time	30S available,5Min reaches optimal state
working pressure	Working pressure difference:0.1~0.5Mpa     Working pressure drop:<0.01Mpa
Maximum withstand voltage	3MPa/10MPa
Leakage rate	1X10-9Pam3/S
Mechanical Components
Base material	Stainless steel
Joint	φ8,φ10,φ12.Flange installation
Sealing material	Fluorine rubber,chloroprene rubber,nitrile rubber,metal seal
Shell protection level	IP40
Installation location	Horizontal installation
Electrical Performance
Electrical connections	DB9 hole,RJ11,5.5x2.1 power fast plug
Display status	With LCD display,without LCD display
Digital quantity	RS232/485,MODBUS protocol,PROFIBUS protocol
Analog quantity	0~5V,4-20mA,1~5V
power supply	24VDC,±15VDC