Introduction

Principle & Structure

The thermal gas mass flowmeter is designed based on the principle of thermal diffusion. The instrument uses the constant temperature difference method to accurately measure the gas. It has the advantages of small size, high degree of digitization, convenient installation and accurate measurement.

The sensor part is composed of two reference-grade platinum resistance temperature sensors. When the instrument is working, one sensor continuously measures the medium temperature T1; the other sensor is self-heating to be higher than the medium temperature T2, which is used to sense the fluid flow rate, which is called velocity sensor. The temperature ΔT=T2-T1, T2>T1, when there is fluid flowing, the temperature of T2 drops because the gas molecules collide with the sensor and take away the heat of T2. To keep ΔT unchanged, it is necessary to increase the temperature of T2. With the power supply current, the gas flows faster, and the more heat is taken away. There is a fixed function relationship between the gas flow rate and the added heat.

technical parameter

Nominal diameter (mm):Pipeline: DN10~DN125
Plug-in type: DN100~DN2000 (customized for special pipes)
Measuring range:See detailed flow parameter table
Accuracy:Pipeline: ±1.0%FS, ±2%FS
Plug-in: ±1.5%FS, ±2.5%FS
Repeatability:±0.25%FS
Response time:2 seconds to reach 63% of final value (a time constant)
Sensitivity:< 0.05 m/s
Power supply:24VDC,AC220V
Total power consumption:less than 20W
output signal:Current output photoelectric isolation 4~20mA: 0~500KΩ
RS485 (Modbus protocol), HART
Alarm signal: 1-2 relay normally open contact signal
24VDC,10A;220VAC,10A
Display content:Mass flow, standard volume flow
Instantaneous flow, cumulative flow, medium flow rate, cumulative running time
Flow percentage (instantaneous flow 6 digits, cumulative flow 10 digits)
Instantaneous flow unit:Nm3/h,Nm3/min,
L/h,L/min,t/h,t/min,
kg/min,kg/h,
Record store query:day record, month record, year record
Instrument shell material:Cast Aluminum & Glass
Sensor Material:Stainless steel 1.4301(304)
Stainless steel 1.4435 (316L)
Applicable pipeline material:Carbon steel stainless steel plastic etc.
Protection class:IP65
Explosion-proof grade:ExdⅡCT2~6 (certification in progress)
Working pressure:Pipeline: ≤40bar
Plug-in: ≤25bar
Connection method:Flange and threaded connections can be used between the flowmeter and the piping
Required straight pipe length:Upstream≥5DN, downstream≥3DN
Flow direction:Positive, negative, net flow
Implementation standard:DIN EN 1092-1-2002
Standard of the place of use for sales (Order remarks)
LVD 2006/95/EC&EMC 2004/108/EC
EN 61326-1::2006 Emission Standard (BS EN50081-1)
EN 61326-1::2006 Immunity Standard (BS EN50082-1)
EN 61010-1:2001 Equipment Safety Requirements: General Requirements
Fluid temperature:-40~+120℃, -40~+220℃
Ambient temperature:-10~+55℃
environment humidity:<90%rh (non-condensing)

Selection table

FGM10-Thermal gas mass flow meter (on-line pipeline type)
FGM20-Thermal gas mass flowmeter (sleeve thread insertion type, with external thread)
FGM30-Thermal gas mass flowmeter (on-line installation plug-in, low-pressure online plug-in, including ball valve and packing gland)
FGM40-Thermal Gas Mass Flow Meter (Flange Insertion Type)

structure type

local header

Remote header with cable length in parentheses

Nominal diameter

DN10~DN125 (online pipeline type)

DN100~DN500 (small diameter plug-in)

DN600~DN2000 (large diameter plug-in)

Power supply

24VDC±10% DC power supply

100~240VAC AC power supply

output signal

No signal output

4~20mA current signal

HART protocol type

display form

no display

Local digital jump display mass flow (instantaneous, cumulative, flow rate, flow percentage)

Accuracy class

±1.5%FS

±1.5%FS

±2.0%FS

Conventional Accuracy (or Fine Calibration Interval)

(optional accessories)

no accessories

gas rectifier
The complete data of this selection table, please contact the sales staff or email to sales@kewill-auto.cn for complete samples.
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