Thermal mass gas flow meter
Introduction
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Thermal gas mass flow meter is designed on the basis of thermal dispersion, and adopts method of constant differential temperature to measuring gas flow. It has advantages of small size, easy installation, high reliability and high accuracy, etc.
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The meter contains two platinum resistance temperature sensors. The thermal principle operates by monitoring the cooling effect of a gas stream as it passes over a heated sensor.
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Gas flowing through the sensing section passes over two sensors one of which is used conventionally as a temperature sensor, whilst the other is used as a heater.
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The temperature sensor monitors the actual process values whilst the heater is maintained at a constant differential temperature above this by varying the power consumed by the sensor.
- The greater the gas velocity, the greater the cooling effect and power required to maintain the differential temperature.
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The measured heater power is therefore a measure of the gas mass flow rate.
Features
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Measuring the mass flow or volume flow of gas
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Do not need to do temperature and pressure compensation in principle with accurate measurement and easy operation.
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Wide range: 0.5Nm/s~100Nm/s for gas. The meter also can be used for gas leak detection
- Good vibration resistance and long service life. No moving parts and pressure sensor in transducer, no vibration influence on the measurement accuracy.
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Easy installation and maintenance. If the conditions on site are permissible, the meter can achieve a hot-tapped installation and maintenance. (Special order of custom-made)
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Digital design, high accuracy and stability
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Configuring with RS485 or HART interface to realize factory automation and integration
| Description |
Specification |
| Medium |
Gas(Except acetylene)
|
|
Pipe size
|
DN10-4000mm |
|
Sensor type
|
Standard Insertion, Hot-tapped Insertion and Flanged
|
| Construction |
Compact and Remote
|
|
Sensor Housing Material
|
SS304 or SS 316
|
|
Pipe Material
|
Carbon steel, stainless steel, plastic, etc
|
| Velocity |
0.1-100N/ms |
Medium temperature
|
Sensor: -30~+200ºC ;Max.350ºC Transmitter:-20-+45ºC
|
|
Working pressure
|
Medium pressure≤1.6MPa
|
| Accuracy |
±1.0~2.5%
|
Power supply
|
Compact type: 24VDC or 220VAC, Power consumption ≤18W Remote type: 220VAC, Power consumption ≤19W
|
|
Response time
|
1S |
Output
|
4-20mA (optoelectronic isolation, maximum load 500Ω), Pulse,RS485 (optoelectronic isolation) and HART
|
|
Alarm output
|
1-2 line Relay, Normally Open state, 10A/220V/AC or 5A/30V/DC
|
Display
|
4 lines LCD display Mass flow, Volume flow in standard condition, Flow totalizer, Date and Time, Working time, and Velocity, etc.
|
|
Protection class
|
IP65 |
Upper Range Value of Common Gas(Unit: Nm3/h. The follow table can be extended)
| Nominal Dia.(mm) |
Air |
Nitrogen(N2) |
Oxygen(O2) |
Hydrogen(H2) |
| 15 |
65 |
65 |
32 |
10 |
| 25 |
175 |
175 |
89 |
28 |
| 32 |
290 |
290 |
144 |
45 |
| 40 |
450 |
450 |
226 |
70 |
| 50 |
700 |
700 |
352 |
110 |
| 65 |
1200 |
1200 |
600 |
185 |
| 80 |
1800 |
1800 |
900 |
280 |
| 100 |
2800 |
2800 |
1420 |
470 |
| 125 |
4400 |
4400 |
2210 |
700 |
| 150 |
6300 |
63000 |
3200 |
940 |
| 200 |
10000 |
10000 |
5650 |
1880 |
| 250 |
17000 |
17000 |
8830 |
2820 |
| 300 |
25000 |
25000 |
12720 |
4060 |
| 400 |
45000 |
45000 |
22608 |
7200 |
| 500 |
70000 |
70000 |
35325 |
11280 |
| 600 |
100000 |
100000 |
50638 |
16300 |
| 700 |
135000 |
135000 |
69240 |
22100 |
| 800 |
180000 |
180000 |
90432 |
29000 |
| 900 |
220000 |
220000 |
114500 |
77807 |
| 1000 |
280000 |
280000 |
141300 |
81120 |
| 1200 |
400000 |
400000 |
203480 |
91972 |
| 1500 |
600000 |
600000 |
31800 |
10152 |
| 2000 |
700000 |
700000 |
565200 |
18048 |
