Wet gas flowmeter LMF-2
1、 Introduction to Wet Gas Flow Meter LMF-2
LMF type is corrosion-resistant and made of stainless steel material, which can be used in the range of corrosive gases. It is one of the commonly used instruments in the laboratory. When measuring the total volume of gas, its accuracy is high, especially at low flow rates, where its error is small. It can be directly used to measure gas flow rate, and can also be used as a standard instrument to calibrate other flow meters. The effective volume of each chamber in a wet gas flowmeter is controlled by the water surface pre injected into the flowmeter, so it is necessary to check whether the water surface reaches the predetermined position during use. During installation, the instrument must be kept level.
2、 Working principle of wet gas flowmeter LMF-2
The wet gas flowmeter is mainly composed of a cylindrical shell, a rotary drum, and a transmission counting mechanism. The wet gas flowmeter is a conventional gas flow detection instrument in the laboratory. As shown in the working principle picture of the wet gas flowmeter, the drum of the wet gas flowmeter is composed of a cylinder and four curved blades. Four blades form four equally sized chambers. The lower half of the drum is submerged in water. The water filling amount is indicated by the water level gauge. When gas enters each chamber from the intake pipe in the middle of the back and is discharged from the top, it forces the drum to rotate. The number of rotations can be counted by a pointer or mechanical counter through a gear mechanism, and the number of rotations of the drum can also be converted into an electrical signal for remote display.
3、 Technical indicators:
Model LMF-2 (anti-corrosion)
Drum flow rate per revolution (m3) 0.005
Rated flow rate (m3/h) 0.5
High flow record (m3) 100
Excess flow (m3/h) 0.75
Small scale value (m3) 0.25 × 10-4
Normal pressure value (Pa) 1000
Accuracy at rated flow rate% ± 1
4、 Precautions
1. During use, it is important to regularly maintain the water level inside the instrument, otherwise it will affect the measurement accuracy.
2. During use, the temperature should be maintained between 15~25 ℃, and the temperature difference between the temperature and room temperature should be ≤ 2 ℃.
3. Fortunately, the instrument pointer runs for several cycles before taking a reading.
4. When the pressure of the measured gas exceeds the normal pressure value by 1-6 times (1-6 Kpa), the instrument can still work. At this time, the pressure gauge should be removed and the installation hole of the pressure gauge should be blocked with a non porous rubber plug. When the flow rate of the measured gas exceeds the rated flow rate and is used within the excess flow range, the instrument can still operate, but the measurement accuracy will be reduced at this time.
5. When the wet gas flow rate is not used for a long time, the distilled water in the instrument should be drained completely. When discharging, use a drain valve first, then lower the meter head downwards, and then lower the outlet pipe downwards. Repeat this process several times before the water in the drum can be drained completely.
6. Wet gas flow should not be installed in a supercooled room to prevent internal icing.
7. Under normal usage, the accuracy should be checked at least once a year.
5、 Usage method
1. Place the instrument on the workbench, adjust the corner screw to center the water bubble on the level, and maintain it for a long time during use.
2. Open the sealing nut of the water level controller and pull out the internal yarn rope.
3. Inject distilled water into the socket of the thermometer or pressure gauge, and stop injecting distilled water when it flows out of the water level controller hole. When the excess distilled water flows out of the water level controller hole along the yarn rope and is clean (when a drop flows out for a long time, it is clean), put the yarn rope into the sealing nut of the water level controller and tighten the sealing nut tightly.
4. Install the thermometer and pressure gauge. (10Pa per small grid)
5. Connect the air path in the direction of inlet and outlet, and seal it.
6. Open the gas valve to perform gas measurement.

Attributes
[Flow meter type]	Positive displacement flowmeter