Question 1

Is the LGF-PA66 magnetic flow meter suitable for wastewater treatment plants? How to select it for influent and return sludge duties?

Accepted Answer

Plant influent carries fibrous debris and return sludge is concentrated and abrasive, so the LGF-PA66 should be specified separately for each process duty.

Influent and lift stations: the medium contains large solids, so specify abrasion-resistant rubber lining with 316L electrodes. Wastewater conductivity is typically above 500μS/cm, making magnetic metering more stable than ultrasonic. Sizes of DN300–DN800 are common; install where the pipe runs full, clear of the turbulent drop zone at headworks weirs.
Return and waste activated sludge: sludge concentrations of 8–15 g/L behave as non-Newtonian fluids; keep line velocity above 1 m/s to prevent deposition. The LGF-PA66 has no obstruction and no moving parts, so it cannot foul or jam like a vortex or turbine meter. Choose hardened-alloy electrodes for abrasion resistance, and scraper-type electrodes where sludge wear is severe.
Effluent metering: where effluent is used for billing or discharge totalisation, select the ±0.5% accuracy class and submit the meter for periodic verification per the applicable regulation.

For sludge duties, set up an electrode-fouling inspection routine and use the transmitter's coating alarm to catch build-up early — far cheaper than pulling the meter for cleaning after the fact. Small chemical dosing points are covered by DN15–DN50 LGF-PA66 units.

For more information, please visit our product pages or contact our technical team.

Question 2

How to configure the LGF-PA66 with an EC32 RTU for a DMA district metering point? Which communication protocols are supported?

Accepted Answer

The standard DMA district metering point is an LGF-PA66 magnetic flow meter plus an EC32 RTU plus minimum-night-flow analysis on the platform side. There are two wiring options: connect the LGF-PA66 RS485 port to the EC32 serial port over shielded twisted pair running Modbus RTU (default 9600bps, 8N1), or feed a 4-20mA analogue signal into an EC32 AI channel. For long cable runs prefer the digital link — better noise immunity, and it also exposes totaliser, empty-pipe alarms and other diagnostics.

Configuration points:

Addresses and registers: when several LGF-PA66 meters share one RS485 bus, assign each a distinct slave address, poll instantaneous and totalised flow registers, and verify the unit scaling factors.
Acquisition strategy: set the EC32 to sample every minute and report every 15 minutes. The 2:00–4:00 minimum-night-flow window must never be skipped — it is the core input for leakage analysis.
Connectivity: the EC32 supports 4G Cat.1 and NB-IoT. In underground valve chambers with weak signal, order the external-antenna version and route the antenna to the chamber mouth.

On the platform, alarm thresholds are set against the baseline of minimum night flow, combined with district pressure data to locate leaking pipe sections. Meter sizes follow the district main — commonly DN80 to DN300 — with flange standards matched to the existing network.

For more information, please visit our product pages or contact our technical team.

Question 3

How long does a battery-powered LGF-PA66 last at off-grid sites? How to choose a low-power metering solution?

Accepted Answer

At metering sites without mains power — agricultural irrigation, distributed abstraction points — the LGF-PA66 can be ordered with a battery-powered low-consumption transmitter using a lithium thionyl chloride battery pack. Typical service life is 3 to 6 years; the main variables are sampling interval and excitation mode.

The low-power version uses intermittent excitation instead of continuous excitation: outside of a measurement the magnetic excitation circuit sleeps entirely, keeping average consumption very low. With a 1-minute sampling interval battery life is around 4 years; shortening the interval to 10-second class noticeably reduces it. For irrigation metering and abstraction supervision, a 1-minute interval is entirely sufficient.

Two selection points:

Size and velocity: battery-powered models cover DN15 to DN300. For low-flow duties check the measurement lower limit of the chosen size — stepping one size down at the same flow rate makes accuracy easier to guarantee.
RTU pairing: for remote reporting, connect the LGF-PA66 via 4-20mA or RS485 to a low-power EC32 RTU that wakes on schedule and uploads over 4G/NB-IoT. The whole system can run on solar — a 20W panel with a 12V/7Ah battery covers most sites.

If sunlight is poor on site or battery replacement labour is expensive, specify one battery capacity step larger and keep the solar interface as an expansion option.

For more information, please visit our product pages or contact our technical team.

Question 4

How to deal with magnetic interference when installing the LGF-PA66 flow meter next to VFDs and large motors?

Accepted Answer

VFDs, soft starters and large motors are strong sources of electromagnetic interference. Typical symptoms are unstable flow readings, periodic 50Hz ripple, or flow spikes when nearby equipment starts or stops. For the LGF-PA66, interference is addressed through grounding, shielding and separation distance.

Grounding: give the sensor its own earth electrode with a grounding resistance of 10Ω or less, never shared with the VFD or the power system. The LGF-PA66 body is made of insulating PA66 composite, which inherently breaks stray currents travelling along the pipe wall — an advantage over metal-bodied meters — but the electrode signal grounding must still be properly implemented.
Shielding: use the supplied shielded signal cable with the shield grounded at one end only, run it in a separate conduit from power cables, and avoid long parallel runs.
Distance: keep the transmitter at least 0.5–1 m away from the VFD cabinet; where this is impossible, add isolation barriers on the supply side and on the 4-20mA output loop.

If an EC32 RTU collects data in the same control cabinet, power the RTU through an isolated DC-DC module so VFD harmonics cannot creep into the communication line via the supply and cause Modbus packet loss.

For more information, please visit our product pages or contact our technical team.

Question 5

How does the LGF-PA66 magnetic flow meter protect against empty-pipe operation? Can it measure accurately in partially filled pipes?

Accepted Answer

A magnetic flow meter works on Faraday's law of electromagnetic induction, and accurate measurement requires the medium to completely fill the pipe cross-section. The LGF-PA66 is a full-bore magnetic flow meter: with an empty or partially filled pipe there is no continuous conductive liquid between the electrodes, the induced voltage becomes distorted, and readings jump or drift from zero. Over time the electrodes also lose the wetting protection provided by the liquid.

Empty-pipe conditions are handled on three levels:

Process design: install the LGF-PA66 at a low point of the line or in a downstream section with stable back pressure so the pipe stays full; add a control valve or weir downstream to raise back pressure if needed.
Function settings: enable empty-pipe detection so the meter cuts its measurement output and raises an alarm once electrode coverage drops below the set threshold, keeping distorted data out of billing records.
Condition monitoring: in intermittent pumping duties, use an EC32 RTU to log empty-pipe alarm timestamps and compare them against pump start/stop logic to separate process-driven empty pipes from equipment faults.

If the duty itself is open-channel gravity flow or a drainage pipe that frequently runs half full, do not force a full-bore magnetic meter into the job. A Doppler radar flowmeter that measures level and surface velocity together, computing flow from the level-area method, is the better fit.

For more information, please visit our product pages or contact our technical team.

Question 6

How is the Doppler radar flowmeter deployed in power plant circulating water and industrial open channels?

Accepted Answer

Typical industrial measurement points: circulating-water intake and return channels, WWTP outfalls, mining tailings return water, and steel-plant effluent channels. These sites share common traits — the medium carries solids or corrosive substances, the channels are usually existing concrete or earth structures, and production cannot stop for a retrofit.

Deployment advantages of the HZ-KSLF Doppler radar flowmeter in industrial channels:

Non-contact measurement: the sensor sits above the channel with no wetted parts — wastewater, tailings slurry and corrosive media cause no fouling or corrosion.
No process shutdown: no channel draining needed; installation and commissioning happen online.
Level, velocity and discharge from one device, with the COSP model improving flow conversion accuracy for irregular cross-sections.
Plant integration: Modbus RTU/TCP or 4G reporting straight into the plant SCADA/DCS; EC32 or EC60 RTUs enable remote monitoring of unmanned pump stations.

For pressurized measurement points (cooling-water supply lines, chemical transfer pipes), choose the LGF-PA66 aviation-grade electromagnetic flowmeter — PA66 composite body, corrosion-resistant and lightweight, IP68 rated for humid plant environments; where drilling into the pipe is not allowed, an external clamp-on ultrasonic flowmeter works. In mixed open-channel plus pipeline water systems, combining radar and electromagnetic meters covers the plant-wide water balance.

For more details, please visit our product pages or contact our technical team.

Question 7

How to select flow measurement equipment for explosive hazardous areas in petrochemical plants?

Accepted Answer

Flow instruments for petrochemical and coal-chemical hazardous areas must carry proper explosion-protection certification — GB 3836 in China, IECEx or ATEX for export projects. Radar flowmeters are low-power electronics and their sensors are typically intrinsically safe (Ex ib), but the complete selection still requires item-by-item verification:

Certificates for sensor and transmitter: the covered protection must match the site's zone classification (Zone 1/Zone 2) and gas group (IIA/IIB/IIC).
Telemetry equipment: use certified RTUs inside hazardous zones — e.g. the Hero V9 series with an intrinsically safe power supply — or install EC32/EC60 RTUs in a safe-area instrument room with signals routed through safety barriers.
Installation workmanship: certified cable glands, equipotential bonding and conduit sealing per explosion-protection codes; poor workmanship voids the protection level of the whole loop.
Surge protection: outdoor petrochemical sites need signal surge protectors, especially on 4G communication lines.

Scenario guidance: for open channels in hazardous areas — effluent treatment sections, circulating-water yards — choose the HZ-KSLF Doppler radar flowmeter in a non-contact installation, with the sensor on a high platform outside the gas boundary, avoiding any contact with flammable atmosphere. For pressurized pipelines inside the boundary, the LGF-PA66 aviation-grade electromagnetic flowmeter offers a corrosion-resistant composite liner suitable for chemically aggressive media. Send us your zone classification drawing before ordering so the technical team can verify the explosion-protection configuration and certificate coverage.

For more details, please visit our product pages or contact our technical team.

Question 8

Can a Doppler radar flowmeter measure flow in tidal rivers with bidirectional flow?

Accepted Answer

Tidal reaches reverse flow direction periodically: ebb tide runs seaward, flood tide pushes inland, the velocity sign flips and magnitudes vary widely. Single-direction meters cannot handle this scenario.

The HZ-KSLF multi-band Doppler radar flowmeter detects flow direction as well as speed. The Doppler shift carries sign information — the echo distinguishes water moving toward the sensor from water moving away — so the instrument outputs positive/negative velocity. The flow calculation classifies each interval as flood or ebb and accumulates flood and ebb volumes separately, giving a complete tidal water balance.

Typical deployments:

Tidal sluice and gate stations: HZ-KSLF mounted on the gate bridge or an observation platform monitors discharge and incoming tide.
Paired with an 80 GHz visual radar level meter for synchronous level data, supporting tide-table analysis of gate operation.
EC60 RTU as the telemetry unit, reporting over 4G/NB-IoT to the water-authority platform with remote viewing and storm-tide alerts.

Selection notes: tidal reaches have wide velocity ranges — confirm the HZ-KSLF velocity span covers both extremes. For estuaries with heavy sediment and strong wind waves, evaluate how the multi-band configuration copes with a complex water surface. In gate-pump coordination scenarios, radar flow data can feed local control logic in the RTU to start or stop pump sets by flow thresholds.

For more details, please visit our product pages or contact our technical team.

Question 9

Doppler radar flowmeter vs. Parshall flume: which is better for open-channel flow measurement?

Accepted Answer

Parshall flumes and weirs infer flow from a level-discharge relationship and require civil works to build a calibrated structure; the HZ-KSLF Doppler radar flowmeter uses the velocity-area method — non-contact surface velocity plus water level — with nothing placed in the channel. Key differences:

Civil investment: a flume needs channel reconstruction and concrete works, typically weeks of construction; a radar flowmeter needs only a mounting bracket and goes live within hours.
Head loss: flumes and weirs raise the upstream water level and reduce conveyance capacity; radar measurement adds zero head loss, which matters in gravity sewers and flood-discharge channels.
Sedimentation: flume throats collect sediment and must be cleaned regularly, or the rating drifts; the HZ-KSLF has no wetted parts and is essentially unaffected.
Maintenance: weir accuracy depends on structure geometry and must be re-surveyed after damage; the radar unit has no moving or wearing parts.
Accuracy: an ideal Parshall flume reaches roughly ±3–5%; a radar flowmeter with the COSP velocity-distribution model performs at a comparable or better level and stays more stable at low depth and low velocity.

Guidance: keep Parshall flumes for new, purpose-built gauging stations where civil works are acceptable. For retrofits, gravity drainage networks and flood channels, the HZ-KSLF Doppler radar flowmeter is usually the more cost-effective option — fast deployment without changing the channel hydraulics.

For more details, please visit our product pages or contact our technical team.

Question 10

How does wind-wave interference affect surface velocity measurement of Doppler radar flowmeters?

Accepted Answer

Wind-driven waves are one of the main error sources in surface velocity radar measurement. Ripples formed on the water surface add an extra Doppler shift on top of the true flow signal, pushing the measured velocity higher or lower than reality. The effect becomes significant above moderate wind (Beaufort 4) on wide channels with a long wind fetch.

The HZ-KSLF multi-band Doppler radar flowmeter suppresses wind-wave interference at three levels:

Multi-band measurement: radar beams at different frequencies respond differently to wind ripples and to bulk flow; fusing multi-band data separates the wind-wave component from the velocity signal.
Spectral filtering: the processor analyses the echo spectrum, rejects the characteristic ripple frequency band and keeps the band carrying the main flow velocity.
Time averaging: multiple instantaneous velocity samples per reporting cycle are outlier-filtered and averaged into a stable output.

On the installation side, mount the HZ-KSLF sensor on a rigid bracket that does not resonate in wind, set the mounting height and beam angle according to the channel cross-section, and keep the main beam away from breaking-wave zones. For critical flood-warning sites, pair it with an 80 GHz visual radar level meter (FMCW) so that level and velocity data can be cross-checked during storms.

Closed conduits are immune to wind waves altogether — for pressurized pipelines choose the LGF-PA66 aviation-grade electromagnetic flowmeter instead.

For more details, please visit our product pages or contact our technical team.

Question 11

Which flange standards does the LGF-PA66 support? Matching GB, ANSI and DIN flanges on old pipelines

Accepted Answer

The LGF-PA66 is built by default to GB/T 9119 and HG/T 20592 flange standards in PN10/PN16/PN25; export orders are produced to ANSI B16.5 (Class 150/300) or DIN EN 1092-1 on request. When retrofitting an old line, DN size alone is not enough — verify four parameters before ordering:

Flange outside diameter and sealing-face type (raised face RF or flat face FF);
Bolt-circle diameter, number and diameter of holes — GB and ANSI hole patterns differ at the same DN and will not line up if mixed;
Pressure rating at or above the maximum working pressure of the line;
Gasket type and thickness compatible with the existing pipeline gaskets.

The PA66 flange is moulded as one piece with the body, so tighten it with a torque wrench in a diagonal, cross-pattern sequence and stay within the manual's torque values — flange crushing from over-torque is the most common installation damage on composite meters. Special legacy standards (old GOST or JIS flanges, for example) can be machined to customer drawings; custom flange lead time is about two weeks. After installation, commission communication with an EC32 RTU and verify the readings against actual line flow before sign-off.

For more information, please visit our product pages or contact our technical team.

Question 12

Is the PA66 composite body flammable? What flame-retardancy rating does the LGF-PA66 achieve?

Accepted Answer

PA66 (nylon 66) is a self-extinguishing engineering plastic with an oxygen index around 24 — far above common combustible plastics. It chars and stops burning once the flame source is removed. Glass-fibre reinforced PA66 formulations reach UL94 V-0: a vertical specimen self-extinguishes within 10 seconds without flaming drips. The aviation-grade reinforced PA66 used for the LGF-PA66 body belongs to this high flame-retardancy class and is safe for outdoor meter pits and pump stations.

For hazardous areas, look at the system in layers:

The sensor (PA66 body, electrodes, excitation coil) is a passive, fully insulated assembly with no power supply or exposed metal — it cannot act as an ignition source by itself;
Explosion protection is defined by the transmitter's marking: choose intrinsically safe Ex ia or flameproof Ex d according to the zone classification;
For petrochemical Zone 1/Zone 2 sites, combine a certified Ex transmitter with the LGF-PA66 sensor and install per GB 3836 / GB 50058, or the IEC 60079 series for export projects.

Material flame-retardancy test reports and transmitter Ex certificates are available before shipment. For zone classification on a specific project, send the site conditions to our technical team — never fit a non-Ex transmitter in a hazardous zone.

For more information, please visit our product pages or contact our technical team.

Question 13

Should an electromagnetic flow meter be installed on the pump suction or discharge side? LGF-PA66 siting in pump stations

Accepted Answer

Install it on the discharge side whenever possible. On the suction side the meter sits under vacuum, where cavitation and degassing cause erratic readings, the flow profile is disturbed by elbows and reducers, and sustained vacuum stresses the flange-to-body seal. The LGF-PA66 has an all-insulated composite body with no liner to debond, but the positive-pressure siting rule still applies.

Siting checklist for pump stations:

Straight run ≥5D upstream and ≥2D downstream; extend the upstream run if a reducer sits close;
Avoid the highest point of the line (air pockets) and the lowest point (sediment); prefer a mid horizontal run or a vertical section with upward flow;
Flooded valve pits require the IP68-rated version; the PA66 body weighs about half of a comparable stainless-steel meter, which matters when lowering it into a confined pit;
With frequent pump cycling the PA66 body withstands water-hammer shocks well, and an EC32 RTU can alarm on flow transients to watch pump health.

If suction-side mounting is unavoidable, confirm the pump runs flooded-suction and keep the meter as close to the pump inlet flange as possible to shorten the vacuum section. Check pipe supports before installation — vibration from the pump outlet travels into the meter body and affects long-term sealing.

For more information, please visit our product pages or contact our technical team.

Question 14

What is the pressure loss of the LGF-PA66 electromagnetic flow meter and does it add pumping energy cost?

Accepted Answer

The LGF-PA66 has a full-bore straight-through measuring tube with no throttling elements and no moving parts. Pressure loss comes only from minor local resistance: a few kPa up to roughly a dozen kPa at rated flow across DN15–DN1200. Orifice plates typically cost 10–40 kPa and turbine meters are comparable or worse, so the electromagnetic design is the energy-saving choice.

Two points for pumping-cost evaluations:

The PA66 body is moulded in one piece with low surface roughness; at the same size and flow it loses slightly less head than a stainless-steel body with a separate liner;
In pump-station retrofits this pressure-loss level barely shifts the system resistance curve, so the pump operating point and long-term electricity consumption stay effectively unchanged.

Where energy KPIs matter, pair the LGF-PA66 with an EC60 RTU: it collects the meter's 4–20 mA or pulse output together with pump power data and computes specific energy (kWh per m³) for the platform, exposing high-consumption periods. On DN300+ lines, every kPa of head saved translates into thousands of kWh per year — the reason many municipal stations replace orifice metering with the LGF-PA66 during upgrades.

For more information, please visit our product pages or contact our technical team.

Question 15

What is the response time of the LGF-PA66 electromagnetic flow meter and how should damping be set for fluctuating flows?

Accepted Answer

The LGF-PA66 aviation-grade composite electromagnetic flow meter uses low-frequency rectangular-wave excitation. Sensor response time is typically under one second, and the transmitter updates the measurement at the 0.1-second level — fast enough to follow flow changes during valve operations or pump starts.

When the process flow itself fluctuates heavily (pump discharge pulsation, intermittent supply), a fast response only reproduces the noise in the reading. Set the damping time constant on the transmitter front panel or via a Modbus register. Field practice:

Custody transfer and totalizing: 3–10 s damping for stable readings;
Process control and PID loops: 1–3 s to balance response and stability;
Leakage detection and transient capture: damping at 0, paired with an EC32 RTU sampling at high frequency to preserve transient details.

After adjusting, watch the instantaneous flow: readings are acceptable when the fluctuation stays within about ±1% of full scale. If it does not, check the line for entrained air or pump cavitation instead of adding more damping — damping only smooths the display and output signals, not the measurement itself. The ±0.2% linearity and ±0.5% accuracy class (DN50–DN100) of the LGF-PA66 are unaffected by the damping setting.

For more information, please visit our product pages or contact our technical team.

Frequently Asked Questions

Is the LGF-PA66 magnetic flow meter suitable for wastewater treatment plants? How to select it for influent and return sludge duties?

How to configure the LGF-PA66 with an EC32 RTU for a DMA district metering point? Which communication protocols are supported?

How long does a battery-powered LGF-PA66 last at off-grid sites? How to choose a low-power metering solution?

How to deal with magnetic interference when installing the LGF-PA66 flow meter next to VFDs and large motors?

How does the LGF-PA66 magnetic flow meter protect against empty-pipe operation? Can it measure accurately in partially filled pipes?

How is the Doppler radar flowmeter deployed in power plant circulating water and industrial open channels?

How to select flow measurement equipment for explosive hazardous areas in petrochemical plants?

Can a Doppler radar flowmeter measure flow in tidal rivers with bidirectional flow?

Doppler radar flowmeter vs. Parshall flume: which is better for open-channel flow measurement?

How does wind-wave interference affect surface velocity measurement of Doppler radar flowmeters?

Which flange standards does the LGF-PA66 support? Matching GB, ANSI and DIN flanges on old pipelines

Is the PA66 composite body flammable? What flame-retardancy rating does the LGF-PA66 achieve?

Should an electromagnetic flow meter be installed on the pump suction or discharge side? LGF-PA66 siting in pump stations

What is the pressure loss of the LGF-PA66 electromagnetic flow meter and does it add pumping energy cost?

What is the response time of the LGF-PA66 electromagnetic flow meter and how should damping be set for fluctuating flows?

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