LDQ-98A-W Wireless Electromagnetic Water Flow Meter

Detail

The LDQ-98A Series Electromagnetic Flow Meter is a velocity-type instrument based on Faraday’s Law of Electromagnetic Induction, designed to measure the volumetric flow rate of conductive media in pipelines. It consists of two main components: an electromagnetic flow sensor and a converter. This series is capable of measuring clean water, wastewater, corrosive media (e.g., acids, alkalis, and salts), and slurry-type conductive liquids.

The converter employs microcontroller-based embedded technology to achieves digital excitation and provides real-time parameters display (including instantaneous flow, cumulative flow, flow velocity, and flow percentage). Additionally, it supports multiple signal outputs such as frequency, current, and wired/wireless communication, enabling remote monitoring and measurement of flow data.

This product series features stable measurement, high accuracy, and long service life, making it widely applicable in petrochemical, petroleum, water supply and drainage, water injection, and chemical dosing systems.

Measurement Principle：Faraday’s Law of Electromagnetic Induction.

When a conductive liquid moves through a magnetic field and cuts the magnetic lines of flux, it generates an induced electromotive force (EMF), expressed as:

EMF=KBVD

Where:

K: Instrument constant

B: Magnetic flux density

V: Average flow velocity within the measuring tube

D: Inner diameter of the measuring tube

During flow measurement, the fluid passes through a magnetic field perpendicular to the flow direction. The conductive liquid induces a voltage proportional to the average flow velocity (i.e., volumetric flow rate). Therefore, the measured liquid must have a minimum conductivity (>5μS/cm). The induced voltage signal is detected by two electrodes in direct contact with the liquid, transmitted via cable to an amplifier, and converted into a standardized output signal.

Key Advantages of This Measurement Method:

1.The measurement tube contains no flow-obstructing internals, effectively eliminating ancillary pressure losses.

2.Since the measurement result is independent of physical parameters such as liquid pressure, temperature, density, viscosity, and conductivity (>5μS/cm), and the sensor signal is an electromotive force (EMF) that maintains an exact linear relationship with average flow velocity, the measurement demonstrates high accuracy and reliable operation.

3.Since the signal is generated within the fully magnetized space and represents an average value across the pipe cross-section, the sensor requires relatively short straight pipe sections, specifically 5 times the nominal pipe diameter (5DN).

4.As only the pipeline and electrodes of the electromagnetic flowmeter come into contact with the measured liquid, corrosion and wear resistance requirements can be met by appropriately selecting electrode and pipeline lining materials.

Electromagnetic Flow Meter Selection

Model Coding:

Electromagnetic Flowmeter Model Selection Code Cross-Reference Table
A	Product Type	1—LDQ-98A-D
		2—LDQ-98A-W
		3—LDQ-98A-P
		4—LDQ-98A-G
		5—LDQ-98A-T
B	Installation Method	Y—Integrated Installation
		F—Split Installation
C	Sensor Diameter	10—010	50—050	200—200	500—500	1000—102
		15—015	65—065	250—250	600—600	1200—122
		20—020	80—080	300—300	700—700	1400—142
		25—025	100—100	350—350	800—800	1600—162
		32—032	125—125	400—400	900—900	1800—182
		40—040	150—150	450—450		2000—202
D	Electrode Material	A—316L Stainless Steel
		B—Hc
		C—Hb
		D—Ti
		E—Ta
		F—Pt
E	Lining Material	A—Polytetrafluoroethylene (PTFE, F4)
		B—Fluorinated Ethylene Propylene (FEP, F46)
		C—Ceramic
		D—Chloroprene Rubber (CR)
		E—Polyurethane (PU)
		F—Fluoroplastic (FS)
F	Medium Temperature	1—≤100℃
		2—≤120℃
		3—≤180℃
		4—≤65℃
		5—≤80℃
		6—≤60℃
G	Power Supply	1—220VAC
		2—24VDC
		3—3.6VDC
H	Ambient Temperature	1—-10℃~45℃
		2—-20℃~55℃
		3—-30℃~80℃
I	Converter Installation Orientation	A—Type A
		B—Type B
		C—Type C
J	Output Signal	1—Frequency 5000Hz 4~20mA(+HRAT)
		2—Frequency 5000Hz 4~20mA RS485/MODBUS
		3—Frequency 5000Hz 4~20mA Other communication standards can be agreed upon
K	Grounding Ring	0—No Grounding Ring
		1—Grounding Ring
		2—Wrapped Grounding Ring
L	Ingress Protection	1—IP 54
		2—IP 65
		3—IP 67
		4—IP 68
M	Ex-protected design	O—Standard Type
		E—Explosion-proof Type
N	Nominal Pressure(MPa)	Directly enter the Nominal Pressure value
O	Flow Range	Directly enter the minimum and maximum values

A—Horizontal			B—Vertical Left			C—Vertical Right

Technical Parameters

Overview:

Normal Pressure Electromagnetic Flow Meter LDQ-98A-D is specifically designed for measuring conductive liquids in oilfield applications, and is also suitable for urban clean water and wastewater measurement. This product features stable measurement, high accuracy, and long service life, and is widely used in petroleum, petrochemical, water supply/drainage, and water treatment systems. It can operate in power-free environments and directly replace conventional water meters.

Features:

1.Minimum flow rate can be accurately measured starting from 0.01 m³/h.

2.Capable of measuring liquids with particles, slurries, ore slurries, and similar media.

3.Measurement is unaffected by changes in fluid density, viscosity, temperature, pressure, or conductivity.

4.No moving parts or obstructions in the measurement tube; zero pressure loss; requires minimal straight pipe sections (5DN upstream, 2DN downstream).

5.Excellent corrosion and wear resistance can be achieved by selecting appropriate sensor lining and electrode materials.

6.Superior anti-interference performance: Resists static electricity and lightning surge voltages ≥1500 V.

7.Proper selection and regular maintenance ensure a service life ≥10 years.

Specification:

Nominal Diameter	DN10~DN2000
Nominal Pressure	0.6MPa~4.0MPa
Ingress Protection	IP68 (Sensor), IP65 (Converter)
Electrode Material	316L Stainless Steel, Hastelloy C, Hastelloy B, Ti, Ta, Pt
Suitable Media	Water, Wastewater, Polymers, Acid/Alkali Solutions, Corrosives, Pulp, Slurry
Medium Conductivity	>5μS/cm
Turndown Ratio	10:1 , 20:1 , 30:1
Accuracy	±0.5%、±1.0%
Lining Material	PTFE (F4)	CR	PU	FEP (F46)
Applicable Diameter	DN10~DN1000	DN50~DN2000	DN10~DN300	DN10~DN200
Medium Temperature	≤100℃	≤65℃	≤80℃	≤120℃
Converter Model	DS08
Ex-protected design	Ex d ib mb IIC T5 Gb
Output Signal	Pulse/Frequency 5kHz, 4~20mA, 4~20mA+HART, RS485 (Modbus RTU)
Electrical Interface	M20×1.5 Internal Thread (M18×1.5 Internal Thread, 1/2NPT Internal Thread, are customizable)
Power Supply	Built-in 3.6V Li-battery (3+ years life, local display only, no output), AC220V±10% 50Hz, DC24V±5%
Ambient Temperature	-30℃~80℃ (requires protective measures below this threshold)
Ambient Humidity	5%~95%

Note: The instrument flanges comply with GB/T 9115-2010. For special requirements, the applicable standard must be specified (ASME B16.5-2009 Pipe Flanges and Flanged Fittings or the Ministry of Chemical Industry standard HG/T 20615-2009 Steel Pipe Flanges (Class Series)).

Installation Size:

Nominal Diameter(mm)	Nominal Pressure (MPa)	Flow Range (m³/h)	Overall Dimensions(mm)				Flange Dimensions(mm)			Weight(Kg)
Nominal Diameter(mm)	Nominal Pressure (MPa)	Flow Range (m³/h)	a	b	c	j	D	Do	n×A	Weight(Kg)
10	1.0~4.0	0.1~1.0	180	360	110	80	90	60	4×14	9.1
15	1.0~4.0	0.2~2.0	180	360	110	80	95	65	4×14	9.7
20	1.0~4.0	0.35~3.5	200	400	150	80	105	75	4×14	11.7
25	1.0~4.0	0.6~6.0	200	400	150	80	115	85	4×14	13
32	1.0~4.0	0.9~9.0	200	410	160	80	140	100	4×18	15
40	1.0~4.0	1.5~15	200	420	170	80	150	110	4×18	16.5
50	1.0~4.0	2.2~22	200	430	180	80	165	125	4×18	19.8
65	1.0~1.6	3.6~36	200	450	200	80	185	145	4×18	21.5
65	2.5~4.0	3.6~36	200	450	200	80	185	145	8×18	21.5
80	1.0~1.6	5.5~55	220	460	216	80	200	160	8×18	23
80	2.5~4.0	5.5~55	220	460	216	80	200	160	8×18	23
100	1.0~1.6	8.5~85	220	480	230	100	220	180	8×18	24.1
100	2.5~4.0	8.5~85	250	490	230	100	235	190	8×22	29
125	1.0~1.6	13~130	250	500	257	100	250	210	8×18	29
125	2.5~4.0	13~130	250	515	257	100	270	220	8×26	36
150	1.0~1.6	19~190	300	530	285	150	285	240	8×22	37.8
150	2.5~4.0	19~190	320	540	285	150	300	250	8×26	43.2
200	1.0	34~340	320	590	342	160	340	295	8×22	52
	1.6		320	590	342	160	340	295	12×22	58
	2.5		350	600	342	160	360	310	12×26	63
	4.0		350	610	342	160	375	320	12×30	67
250	1.0	50~500	400	630	383	210	395	350	12×22	75
	1.6		400	635	383	210	405	355	12×26	78
	2.5		400	640	383	210	425	370	12×30	83
	4.0		400	655	383	210	450	385	12×33	87
300	1.0	75~750	450	680	433	230	445	400	12×22	88
	1.6		450	690	433	230	460	410	12×26	94
	2.5		450	700	433	230	485	430	16×30	102
	4.0		450	715	433	230	515	450	16×33	110
350	1.0	100~1000	500	685	435	305	505	460	16×22	132
350	1.6	100~1000	500	695	435	305	520	470	16×26	143
400	1.0	140~1400	500	745	495	305	565	515	16×26	180
400	1.6	140~1400	500	755	495	305	580	525	16×30	193
450	1.0	170~1700	600	790	540	385	615	565	20×26	210
450	1.6	170~1700	600	800	540	385	640	585	20×30	222
500	1.0	210~2100	600	850	600	385	670	620	20×26	240
500	1.6	210~2100	600	870	600	385	715	650	20×33	252
600	1.0	300~3000	600	955	705	385	780	725	20×30	330
600	1.6	300~3000	700	985	705	385	840	770	20×36	345
700	0.6	400~4000	700	1070	822	465	860	810	24×26	430
700	1.0	400~4000	700	1090	822	465	895	840	24×30	450
800	0.6	550~5500	800	1180	930	545	975	920	24×30	540
800	1.0	550~5500	800	1200	930	545	1015	950	24×33	560
900	0.6	700~7000	900	1285	1038	635	1075	1020	24×30	650
900	1.0	700~7000	900	1300	1038	635	1115	1050	28×33	670
1000	0.6	580~8500	1000	1385	1140	705	1175	1120	28×30	800
1000	1.0	580~8500	1000	1410	1140	705	1230	1160	28×36	830
1200	0.6	1250~12500	1200	1627	1350	854	1405	1340	32×33	950
1400	0.6	1650~16500	1400	1823	1524	1034	1630	1560	36×36	1300
1600	0.6	2100~21000	1600	2033	1726	1234	1830	1760	40×36	1650
1800	0.6	2600~26000	1800	2330	1900	1500	2045	1970	44×39	2080
2000	0.6	3000~30000	2000	2270	2148	1515	2265	2180	48×42	2580

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