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Technical Specifications
| Item | 20 | 60 | 100 | 200 | 300 |
| Measured Variable | Mass Flow | ||||
| Flow Range (L/min) | 0.2~20 | 0.6~60 | 1~100 | 2~200 | 3~300 |
| Turndown Ratio | 1:100 | ||||
| Outputs | |||||
| Analog Output | 4–20 mA, load resistance ≤ 650 Ω | ||||
| Communication Output | RS485 interface, MODBUS-RTU protocol | ||||
| Pulse Output | Pulse width 2 ms, passive output, external voltage ≤ 30 VDC | ||||
| Alarm Output | 1 channel | ||||
| Power Supply | |||||
| Supply Voltage | 9–24 VDC (Note: 24 VDC is required when using 4–20 mA current output) |
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| Power Consumption | ≤ 2 VA | ||||
| Electrical Connection | GX16-7 aviation connector | ||||
| Performance | |||||
| Accuracy | ±1.5% FS | ||||
| Repeatability | 0.5% | ||||
| Instantaneous Flow Resolution | Flow < 100 L/min: 0.01 Flow ≥ 100 L/min: 0.1 | ||||
| Process Conditions | |||||
| Medium | Air, Oxygen, Nitrogen, Argon, Carbon Dioxide, Carbon Monoxide | ||||
| Process Pressure | ≤ 1 MPa | ||||
| Process Loss | ≤600P | ≤1000P | ≤1000P | ≤2000P | ≤2000P |
| Ambient Conditions | |||||
| Operating Temperature | -10℃~55℃ | ||||
| Operating Humidity | ≤ 80% RH (non-condensing, no icing) | ||||
| Storage Temperature | -25℃~80℃ | ||||
| Ingress Protection | IP52 | ||||
| Construction | |||||
| Material | Housing: Aluminum alloy Base: SS304 stainless steel | ||||
| Weight | 750g | ||||
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Applications
The Micro Thermal Mass Gas Flow Meter is suitable for gas flow measurement and monitoring in the following fields:
Medical equipment and devices
Oil and gas industry
Chemical processing plants
Energy and power systems
Industrial gas monitoring and control
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Measuring principle
The flow meter operates based on the thermal mass flow measurement principle. Two temperature sensors are integrated into the measuring section of the meter. One sensor measures the actual process gas temperature, while a heated Pt100 thermal resistor is maintained at a constant temperature difference relative to the process temperature.
As the mass flow rate of the gas increases, the cooling effect on the heated sensor becomes stronger, requiring a higher electrical current to maintain the constant temperature difference. By monitoring the current supplied to the heating element, the instrument accurately calculates the gas mass flow rate.
This method enables direct mass flow measurement independent of pressure and temperature variations, ensuring stable and reliable performance.
