FMM504 Thermal Gas Mass Flow Meter

The FMM 504 series of thermal gas mass flow meters are instruments that measure the mass flow of gases using the principle of heat transfer.

The meter’s sensor consists of two reference-level thermal resistors (platinum RTD). One is the mass velocity sensor T1, and the other is the temperature sensor T2 that measures the temperature change of the gas. When the two RTDs are placed in the gas to be measured, the sensor T1 is heated to a constant temperature difference above the gas temperature, and the other sensor T2 Used to sense the temperature of the gas being measured. As the gas mass flow rate increases, the airflow takes more heat, and the temperature of the sensor T1 decreases. To maintain a constant temperature difference between T1 and T2, the heating power of T1 increases. According to the law of Kin’s law of thermal effect, the heating power P, the temperature difference ΔT (T1-T2) and the mass flow rate Q have a certain mathematical relationship.

Parameter :

ITEMS Plug-in type Pipe segment type
Installation process form sleeve + ball valve, flange connection flange, threaded connection
Pipe diameter range DN80~6000mm DN15~2000mm
Work pressure Medium pressure ≤2.5Mpa Medium pressure ≤4.0Mpa
Sensor material stainless steel Stainless steel, carbon steel
Measuring medium Various gases (except acetylene gas)
Flow rate range 0 ~ 120Nm / s (20 ° C, 101.33KPa)
Range ratio usually 1000: 1 (depending on the range of calibration flow)
Accuracy ±1% of reading ±0.5% of full scale
Ambient temperature -40°C to +85°C (no display); -30°C to +70°C (with display)
Medium temperature -40 ° C ~ +100 ° C; -40 ° C ~ +200 ° C;-40 ° C ~ +450 ° C; -40 ° C ~ + 510 ° C
Power supply One machine (DC24V or AC220V ≤ 18W) split converter (AC220V ≤ 19W)
Output signal 4-20mA (optical isolation, maximum 500Ω load) RS-485 (optical isolation)
Pipe material Glass, stainless steel, plastic, etc.
Display Integrated: 8-bit field + 24 prompts, Split type: 10×2 Chinese character display
Display content Mass flow, standard volume flow, cumulative flow, standard time, cumulative running time, etc.
Split converter profile Wall-mounted: 213 × 185 × 107mm Panel mounted: 160 × 80 × 160mm
Converter and primary table distance ≤25m (the primary meter is powered by the split converter), ≤1000m (the primary meter is powered by the field)
Protection level IP67
Explosion ExdIICT4

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