Battery powered electromagnetic flowmeter is a measuring instrument designed for the actual requirements of water supply enterprises. It can optimize water supply and ensure accurate water trade measurement and settlement. Good reliability and stability.

The battery powered electromagnetic flowmeter converter adopts internal battery power supply and does not require external power supply. It is suitable for working conditions where the outdoor power grid cannot be reached and the power grid is difficult to lay. It is particularly suitable for monitoring, metering, and settlement of tap water supply systems. The QTLD/D battery powered electromagnetic flowmeter converter adopts ultra-low power circuit technology to design stable and reliable excitation and signal processing circuits to achieve measurement functions, ensuring the reliability and stability of the converter. At the same time, the system management technology greatly reduces system power consumption, saves power supply costs, and achieves better measurement.

Working principle of battery powered electromagnetic flowmeter

According to Faraday’s principle of electromagnetic induction, a pair of detection electrodes are installed on the tube wall perpendicular to the axis of the measuring tube and the magnetic field lines. When the conductive liquid moves along the axis of the measuring tube, it cuts the magnetic field lines and generates an induced potential. This induced potential is detected by the two detection electrodes, and the value is proportional to the flow rate. Its value is:

E=KBVD

In the formula:

E – Induced potential;

K – coefficient related to magnetic field distribution and axial length;

B – Magnetic induction intensity;

V – average flow velocity of conductive liquid;

D – electrode spacing; (Measuring the inner diameter of the tube)

The sensor uses the induced potential E as a flow signal, which is transmitted to the converter. After amplification, transformation, filtering, and a series of digital processing, the instantaneous and cumulative flow rates are displayed on a backlit dot matrix LCD. The converter has 4-20mA output, alarm output and frequency output, and is equipped with communication interfaces such as RS-485, and supports HART and MODBUS protocols.

Technical parameters

property	Technical parameter
Nominal diameter	DN10——DN3000mm
precision	±0.5% of the indicated value, optional ±0.3% or ±0.2% of the indicated value
Lining material	Teflon,PFA,F46, Neoprene, polyurethane rubber, high temperature rubber
Electrode material	SUS316, Hastelloy B/C, Titanium, tantalum, platinum-iridium, stainless steel coated with tungsten carbide
Electrode form	Standard type, scraper type, can be changed
Connection mode	Flange connection, insert connection, clamp connection, clamp connection, connected by the nonans
Medium temperature	monomorph	-20℃～+60℃
	split	Neoprene lining, polyurethane lining	-10℃～+80℃
		PTFE lining, PFA lining, F46 lining	-10℃～+160℃
Nominal pressure	0.6～4.0Mpa（Special pressures can be customized）
Ambient temperature	-25℃～+60℃
Ambient humidity	5～100%RH（Relative humidity）
Dielectric conductivity	≥20μs/cm
Measuring range	1500:1 Flow rate setting <15m/s
Structural form	One type, sub-type, immersion type, explosion-proof type
Guard isopole	IP65、IP68selectable
Explosion-proof mark	ExmdIIT 4
Product standard	JB/T9248-1999 Electromagnetic flowmeter

Advantages of battery powered electromagnetic flowmeter

1. Micro power design, five 3.6V lithium batteries, continuous operation for 5-10 years, and easy battery replacement;
2. The monitor adopts an LCD large screen LCD display, which can display multiple flow parameters such as instantaneous flow rate, flow velocity, cumulative total amount in both directions, and alarm prompt;
3. There are no movable or resistance components inside the measuring tube, and there will be no entanglement or blockage. There is almost no pressure loss, and it can work reliably and continuously for a long time;
4. Wide measurement range, flow velocity measurement range can reach 0.05m/s~10m/s;
5. Measurement stability, measurement accuracy is not affected by changes in physical parameters such as temperature, pressure, viscosity, density, etc. of the measured medium;
6. It has the function of pulse output and GSM wireless data remote transmission.
7. It has a data saving function, which can save 1000 sets of traffic data, and the interval between data storage times can be set arbitrarily and data can be queried.
8. Widely applicable, it can be used in fields such as sewage treatment, water conservancy engineering, urban water supply, etc.
9. Stable work, high measurement accuracy, and strong anti-interference ability.

There are five aspects for selecting battery powered electromagnetic flow meters:

1、 Flow range

The appropriate electromagnetic flowmeter diameter should be selected based on the flow range (refer to the selection table for electromagnetic flowmeter diameter and flow range). Generally speaking, electromagnetic flow meters can measure flow velocities ranging from 0.3m/s to 15m/s.

2、 Signal output mode

Nowadays, electromagnetic flow meters are mostly equipped with pulse output, with 4-20mA output and 0-10mA output.

3、 Installation method

The connection methods between sensors and pipelines include flange connection, flange clamp connection, sanitary connection, and threaded connection. Select according to the on-site process requirements.

4、 Tested medium

1. Electromagnetic flow meters are not suitable for measuring gases, vapors, and liquids containing large amounts of gas or large solid particles.
2. Ensure that the conductivity of the measured medium is greater than 5U.
3. Determine whether to use an integrated or separated type based on the environment used on site, and for media with high temperatures, the separated type is suitable.
4. Determine the appropriate lining and electrode materials based on the acid, alkali, and salt properties of the tested medium.
5. Determine the pressure level based on the on-site process and equipment requirements.

5、 Power supply mode

Based on the on-site situation, select the power supply for the electromagnetic flowmeter. We can provide battery powered electromagnetic flow meters, 24V (18-28V) DC power supply types, and 220V (85V -265V) AC power supply types.

Selection of installation location for battery powered electromagnetic flowmeter

1. The flow direction indicator on the sensor must be consistent with the direction of the measured medium flow inside the pipeline.
2. The installation position must ensure that the measuring tube is filled with the measured medium.
3. Choose a location with smaller fluid flow impulse, which should be away from the pump and local resistance components (valves, elbows, etc.)
4. When measuring two-phase fluids, a location that is not prone to phase separation should be selected.
5. Installation in areas with negative pressure inside the pipe should be avoided as much as possible.
6. When the measured medium easily causes adhesion and scaling on the inner wall of the electrode and measuring tube, it is recommended that the flow velocity inside the measuring tube should not be less than 2m/s.
   At this point, a tapered pipe slightly smaller than the process diameter can be used. To clean electrodes and measuring tubes without interrupting flow in the process pipeline, sensors can be installed in parallel with cleaning ports.

Horizontal installation

When installing the sensor horizontally, the two electrodes should be taken as horizontal positions. This way, if the medium contains bubbles or sediment, the bubbles will not adsorb near the electrodes, causing an open circuit at the input end of the converter, and the sediment will not cover the electrodes, resulting in zero drift and other phenomena.
To ensure that the sensor is filled with the measured medium inside the measuring tube, the sensor position should be slightly lower than the height of the pipeline, or the sensor should have a certain positive pressure.

Vertical installation

Vertical installation of liquid-solid two-phase media is more reasonable, as it can prevent phase separation of the measured medium and evenly wear the lining around the inner measuring tube of the sensor.
When installed vertically, the flow direction of the medium should be from bottom to top to ensure that the measuring pipeline inside the sensor is always filled with the measured medium.

Electromagnetic flowmeter is used in: petroleum, chemical, steel, food, power, paper, metallurgy, water supply and drainage, petrochemical, medical and other industries.