Question 1

LGF-PA66 Flow Meter: Water Hammer Resistance in Pump Cycling Sites

Accepted Answer

Water hammer comes from sudden pump starts/stops or fast valve closure, with transient pressure peaks reaching several times the normal working pressure. It is the most common risk in valve pits and pump-house metering points. The LGF-PA66 body is injection-molded from aviation-grade PA66 composite and rated PN16. PA66 is a tough material - unlike cast iron bodies it carries no brittle-cracking risk under transient shock; combined with a PTFE liner and 316L electrodes, it steadily withstands the pressure fluctuations of normal municipal pump cycling.

For frequent pump-cycling sites we still recommend three measures:

Install a water hammer eliminator or slow-closing check valve downstream of the pump to cut pressure peaks at the source;
Do not mount the LGF-PA66 right at the pump outlet - keep at least 5D distance and respect the straight-run requirement of 5D upstream / 3D downstream;
For severe fluctuations choose the PN25 flange rating or contact our technical team for a custom configuration.

The PA66 body is about 40% lighter than stainless steel (DN100 reference), so inertial loads on flange joints during water hammer are lower; with bolts tightened to standard torque, long-term sealing stays reliable.

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

Question 2

How Is a 10cm Blind Zone Achieved in Radar Meters?

Accepted Answer

The blind zone is the hard gate in level-meter selection: dry-season sewer water can be only a few centimeters deep, and meters with large dead bands simply cannot see it. Ecolor's visual fusion radar water level gauge pushes the blind zone down to 10cm with two design choices — a millimeter-wave RF chip lets transmit and receive antennas sit extremely close together, and an integrated lens design shortens the physical distance from RF front-end to water; the 4GHz bandwidth of the 76-81GHz band provides fine enough range bins that near-field echoes do not merge with transmit leakage.

A three-step selection method for shallow-water sites:

Check the blind zone: measurement start must sit below the historical minimum level. With a 0.1m-65m range and 10cm blind zone, valid measurement begins almost at the channel bed;
Check mounting clearance: manholes and culverts offer little headroom — choose a compact unit with bracket/thread mounting; the narrow 14°/10° beam keeps wall clutter out;
Check the data link: low-water periods are often dry seasons with weak site power — prefer low-power models (over 2 years of autonomy) and hang an EC32/EC60 RTU on RS485 reporting via NB-IoT for minimum comms power.

If the site also needs flow data, go straight to a Doppler radar flow meter for shallow open channels (level, velocity and flow in one unit); for level-only outfalls, retention basins and pump-station forebays the visual fusion radar gauge suffices, and its camera eliminates manual photo patrols.

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

Question 3

River Outfall Monitoring: Required Equipment

Accepted Answer

River outfalls are the last checkpoint of discharge supervision — regulators require them to be visible, measurable and traceable. A standard outfall monitoring site is built from four layers:

Level layer: a visual fusion radar water level gauge mounted above the outfall well or open channel records the discharge hydrograph at ±1mm accuracy while its camera keeps site imagery — illegal or excessive discharge has nowhere to hide behind dual evidence of data plus photos;
Water-quality layer: water-quality sensors (COD, ammonia nitrogen, pH, etc.) hang off the gauge's spare RS485 port, so one bus carries quality data without a separate acquisition box;
Flow layer: for full-pipe pressured outfalls add an LGF-PA66 aviation-grade electromagnetic flow meter for total discharged volume; for open-channel sections a Doppler radar flow meter measures level, velocity and flow contactlessly;
Telemetry layer: an EC32 or EC60 RTU aggregates all sensors and backhauls to the supervision platform over 4G/NB-IoT, with IP68 protection for riverside humidity and solar-plus-battery power where mains supply does not exist.

Deployment notes: survey the outfall type (open channel / pipe / culvert) before fixing the sensor mix; keep the mounting position clear of direct echo interference; and align level, quality and imagery on one timeline in the platform, otherwise compliance reports lose credibility.

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

Question 4

How Does the Camera on a Radar Level Meter Work?

Accepted Answer

Conventional radar level meters show only an echo curve — O&M staff cannot confirm what actually happened on site. The visual fusion radar water level gauge integrates a 5-megapixel HD camera into the measurement unit, so when data looks abnormal, one photo on the platform locates the cause without a site visit.

There are three working modes: scheduled capture — images uploaded on a set cycle (e.g. morning and evening), building a level-image archive; on-demand snapshot — the platform triggers an instant photo for intensified monitoring during flood season; alarm linkage — when water reaches the device threshold, a photo is captured automatically with the alert, allowing the inundation process to be reconstructed afterwards.

Installation adds no extra work: the unit mounts on a manhole rim or pole with its dedicated bracket (bracket or thread mounting), requires no field wiring, and the camera shares the radar's line of sight — once installed, both are aimed at the water surface. Power is 9-28VDC; with the 96AH battery (expandable) and a solar panel, low-power operation exceeds 2 years of autonomy, and capture frequency can be tuned to the power budget. Images and level data both backhaul via RS485/RTU (EC32, EC60) and are stored under the same timestamp, so records never drift apart.

This capability sees the heaviest use at urban waterlogging points, river outfalls and pump-station forebays — disputed readings, complaint verification and flood reviews are all settled with imagery.

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

Question 5

Sewer Monitoring: Radar Level Meter vs Ultrasonic

Accepted Answer

Underground sewer environments share two traits: near-saturated humidity plus corrosive gas and foam — exactly the weaknesses of ultrasonic level sensors. Sound attenuates heavily in saturated vapor, and temperature gradients cause sound-speed drift, so ultrasonic meters often show jumpy or missing readings in sewage wells.

The visual fusion radar water level gauge takes a different physical path: 76-81GHz electromagnetic waves are immune to vapor and thermal stratification. Its IP67 enclosure uses corrosion-, acid- and impact-resistant materials, and the unit mounts at the manhole opening — no confined-space entry needed, which reshapes O&M cost structures as safety regulations tighten. ±1mm accuracy, a 10cm blind zone and a 0.1m-65m range cover everything from dry-season low water to full-bore flood conditions.

The decisive difference is evidence capability. Ultrasonic gives a data curve only; the visual fusion radar gauge integrates a 5-megapixel camera with scheduled or real-time photo capture. When a level reading looks abnormal, one site photo tells you whether it is floating debris, a dirty sensor or genuine flooding — solving the industry pain of "data without the field". An RS485 port can also carry water-quality sensor data, backhauled via EC32/EC60 RTUs over 4G or NB-IoT.

Bottom line: for municipal stormwater/sewer networks and outfall monitoring, choose the visual fusion radar level meter; keep ultrasonic sensors for open, dry, non-corrosive clean-water tanks.

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

Question 6

Why Use 76-81GHz in a Visual Fusion Radar Level Meter?

Accepted Answer

The frequency band determines both resolution and anti-interference capability of a radar level meter. Ecolor's visual fusion radar water level gauge uses 76-81GHz FMCW technology, and the 4GHz sweep bandwidth is the underlying reason it achieves ±1mm accuracy — distance resolution is inversely proportional to bandwidth, so a wider band separates adjacent echoes more cleanly.

Tiny dead band: millimeter-wave RF chip with an integrated lens design reduces the blind zone to as low as 10cm, keeping data valid in shallow channels and low-water conditions;
Narrow beam: -3dB beam angle of 14° horizontal / 10° vertical keeps clutter from well walls, brackets and cables outside the main lobe — no careful aiming required during installation;
High SNR: the high band and wide bandwidth reliably extract weak water-surface echoes, so readings stay continuous even with foam or vapor.

Compared with common 26GHz pulse radar, the shorter wavelength allows a much smaller antenna aperture for the same beam angle, which is precisely why a 5-megapixel camera can be integrated into the same enclosure. Data output is RS485, connecting directly to EC32 or EC60 RTUs to build 4G/NB-IoT remote monitoring stations.

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

Question 7

Is LGF-PA66 Suitable for Outdoor Installation Without a Shelter?

Accepted Answer

Unstabilised nylon has poor UV resistance, but the LGF-PA66 body is moulded from a UV-stabilised compound with additives, so normal outdoor exposed installation is fine.

Practical guidance by region:

Regions with normal UV levels: exposed installation is not a problem — body and cable life far exceeds the maintenance cycle of the plant;
High-altitude, high-UV regions: fit a simple sunshade for permanently exposed units; it protects signal cables and connectors too, at negligible cost;
Solar-powered irrigation metering stations (LGF-PA66 + EC32 RTU) usually ship with an instrument box or sun cover as standard practice.

The IP68 transmitter suits outdoor pit and surface mounting, although displays and buttons last longer in shade.

Inspection is simple: once a year, check the body surface for chalking or heavy colour change and retighten any loose cable glands. If ageing signs appear, add a protective cover — no need to replace the meter.

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

Question 8

How to Tighten LGF-PA66 Flange Bolts Without Damaging the Flange?

Accepted Answer

PA66 flanges are moulded as one piece with the body. They carry normal pipeline loads well but do not tolerate point loading the way steel flanges do — the tightening method decides whether a flange survives.

Key points:

Flange dimensions follow GB/T 9119, so bolt patterns match standard pipeline flanges with no adapters;
Tighten diagonally in stages: 30%, then 60%, then final torque. Use a calibrated torque wrench; never an impact wrench;
Torque values depend on size (DN15–DN300) — follow the torque table in the manual or request it from the technical team;
Gaskets: full-face rubber or PTFE-envelope types; avoid undersized ring gaskets that concentrate stress;
No hot work: never use the body as a welding ground or weld near the meter.

After installation, fill the line slowly to vent air, then raise pressure gradually and check the flange faces for leaks. During pipeline hydrostatic testing, isolate the LGF-PA66 — test pressures above the rated value damage both liner and body.

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

Question 9

Does PA66 Moisture Absorption Affect LGF-PA66 Accuracy?

Accepted Answer

Unreinforced PA66 does absorb noticeable moisture — a fair concern. The LGF-PA66 uses glass-fibre reinforced PA66, which absorbs far less water and holds its moulded dimensions well.

More importantly, the wetted parts of an electromagnetic flow meter are only the PTFE liner and the electrodes; the medium never touches the PA66 body. The body provides structural support and locates the magnetic circuit — minor dimensional change from moisture uptake does not alter the measuring bore or the induced voltage signal.

The IP68 rating is designed for long-term immersion in the first place: flooded valve pits and rain-soaked outdoor installations are design scenarios, so humid-air absorption sits well inside the engineering margin. Units are running year-round in humid southern valve pits and coastal high-salt-spray sites.

What genuinely needs attention: strong oxidising acids (concentrated sulphuric, nitric) must be reviewed with the technical team before selection, and high-chloride media call for Hastelloy or titanium electrodes. Neither issue relates to moisture.

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

Question 10

Can LGF-PA66 Measure High-Temperature District Heating Water?

Accepted Answer

The LGF-PA66 is rated for media from -20°C to +120°C as standard. Primary heating network supply water typically runs at 75–95°C and secondary networks at 50–70°C, both inside the range. District heating loops are closed systems with working pressures usually below 1.6 MPa; the LGF-PA66 carries a 1.6 MPa or 4.0 MPa rating depending on size, which covers normal duty.

Two boundaries to be clear about:

Where instantaneous excursions above 120°C are possible (steam-to-water plants, abnormal conditions near heat sources), specify the high-temperature variant and confirm parameters with the technical team before ordering;
In hot metering rooms, use the split version and mount the transmitter in a ventilated cabinet or on a wall away from heat.

For heat billing retrofits the PA66 body helps as well: a DN100 meter weighs only about 3.5 kg, so installation in cramped substations needs no lifting gear. Combined with heat calculators or EC32 RTU telemetry for supply/return temperature and flow, consumption billing and network loss analysis run on the platform side.

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

Question 11

What Is the Minimum Flow Rate of DN15/DN25 LGF-PA66 Flow Meters?

Accepted Answer

The lower velocity limit determines the minimum measurable flow. The LGF-PA66 measures stably down to 0.1 m/s with a turndown ratio of up to 50:1. Converted to common small sizes:

DN15: minimum approx. 0.06 m³/h;
DN25: approx. 0.18 m³/h;
DN50: approx. 0.71 m³/h.

These sizes cover low-flow duties such as chemical dosing lines, laboratory water supply and secondary distribution branches. Keep the normal duty point between 30% and 70% of full scale; avoid continuous operation below 20% — the induced signal becomes weak and readings drift.

Unlike full-scale error specifications, the ±0.5% (DN50-100) accuracy of the LGF-PA66 is reading-based, so relative error stays controlled at low flow. The moulded PA66 body with PTFE liner keeps the bore smooth and scale-resistant — critical at small diameters, where liner deposits directly constrict the flow path and add error.

For remote sites without mains power, pair the meter with a Hero V9 EC32 RTU: data reporting over 4G/NB-IoT into the smart water platform, where totalisers and low-flow alarms are configured.

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

Question 12

The LGF-PA66 is rated at ±0.2% — how much do field installation conditions affect actual accuracy?

Accepted Answer

The ±0.5% (DN50-100) figure is the reading accuracy of the LGF-PA66 under a wet-calibration condition with the installation requirements met. Real on-site accuracy is decided mainly by the flow profile: repeatability is 0.1%, so once the site conditions are right, long-term accuracy does not degrade by an order of magnitude.

Factors that hurt field accuracy, largest first:

Short straight runs come first. If the upstream run is under 5D or the meter sits right behind an elbow, valve or reducer, the distorted velocity profile can push the error above 1%; where possible extend the upstream run to 10D or fit a flow conditioner.
A partially filled tube and gas bubbles break the basic measuring premise — that is a wrong mounting location; relocate the meter rather than tolerating it.
When conductivity is near the 5 µS/cm lower limit the signal margin is thin: choose the remote (split) version to shorten the signal cable and do a zero calibration under full-pipe, zero-flow conditions before startup.
Poor earthing causes zero drift. The LGF-PA66 has an insulating body, so there is no pipe-wall corrosion issue, but the converter earthing terminal must still be reliably grounded.

A practical way to verify field accuracy is a portable ultrasonic comparison or a master-meter check in series; a deviation within ±0.5% indicates the installation is acceptable. Order the 0.2-class meter and install it per the manual, and the field accuracy will hold. For more information, please visit our product page or contact our technical team.

Question 13

What metering equipment do water-abstraction permit rules require at intakes, and can the LGF-PA66 meet remote-supervision requirements?

Accepted Answer

Water-abstraction permit rules require the abstractor to install qualified metering at the intake — one meter per well or offtake — and the data feeds water-resource fee (tax) accounting and planned-use assessment. Supervision focuses on three things: accurate measurement, reliable operation and auditable data.

Accuracy: the meter must have a valid verification basis. Every LGF-PA66 is wet-calibrated individually at the factory and ships with a verification certificate; periodic verification follows JJG 1033, the Chinese electromagnetic flowmeter verification regulation. For points tied to water-resource fee accounting, order the ±0.5%（DN50-100） accuracy class. Reliability: field intakes are harsh environments. The LGF-PA66 body is aviation-grade PA66 composite whose corrosion resistance comes from the material itself rather than a lining, so there is no rust-maintenance burden, and IP68 protection allows buried or submerged pit installation. Auditability: data must be readable remotely and leave an auditable trail. With the Hero V9 EC32 RTU the meter reports over 4G/NB-IoT, the platform automatically builds daily and monthly totals, and the full consumption curve is retained — inspectors do not need to visit the site.

Scope matters: for pressurised, always-full points such as borehole outlets and pump discharges, LGF-PA66 plus EC32 RTU is a proven combination, and off-grid sites can add solar power. Open-channel intakes cannot use an electromagnetic meter — choose a radar or ultrasonic open-channel flowmeter instead. Before retrofitting intake metering, confirm the required accuracy class and data-transmission protocol with the local water authority. For more information, please visit our product page or contact our technical team.

Question 14

How much do gas bubbles from dissolved air affect the accuracy of the LGF-PA66 electromagnetic flowmeter?

Accepted Answer

An electromagnetic flowmeter measures the volume flow of the liquid. Bubbles entering the measuring tube displace liquid and change the impedance of the conductive path between the electrodes; the result is a fluctuating or high reading, and how bad it gets depends on the gas fraction and the bubble pattern.

Uniform microbubbles below about 1% gas volume have a negligible effect on the LGF-PA66. As the gas fraction rises the reading turns unsteady; above roughly 5% the error becomes significant, and in severe cases the value jumps sharply and the empty-pipe alarm may trigger. Occasional large slugs are worse than uniform microbubbles — the signal dips the moment a slug sweeps past the electrodes.

Deal with it on site in this order:

Find where the gas comes from first — air drawn in through a pump suction leak or a negative-pressure section is the most common cause. Fix the leak before worrying about accuracy.
Mount the meter on a pressure-stable section such as a pump discharge, away from the highest point of the line, sudden enlargements and sharp bends; add an air-release valve upstream if needed.
On vertical pipes run the flow upward so bubbles rise through and do not linger in the measuring tube.

The LGF-PA66 has built-in empty-pipe detection. During commissioning set the empty-pipe threshold against the actual conductivity of the medium, so that gas locking or a dry line raises an alarm on the platform immediately instead of feeding bad data into statistics. For more information, please visit our product page or contact our technical team.

Question 15

Can the LGF-PA66 electromagnetic flowmeter measure bidirectional flow accurately in sewers with frequent backflow?

Accepted Answer

When tidal backwater or a rising downstream level pushes flow backwards in a storm or sanitary sewer, the metering point must measure in both directions. The LGF-PA66 works on Faraday's law of induction: the polarity of the induced voltage follows the flow direction, so the velocity signal carries a natural sign — it measures forward and reverse flow without any mechanical direction-sensing device.

The converter keeps separate forward and reverse totals and also outputs net flow (forward minus reverse). Reports can show the reverse volume separately, which quantifies external water intrusion and backflow frequency. With the EC32 RTU the forward total, reverse total, net flow and instantaneous direction all enter the data stream, so the platform can analyse backflow patterns by pumping-station operating period and support interception decisions.

Installation points:

Choose a pressurised, always-full section such as a pump discharge line. Electromagnetic meters cannot measure partially filled gravity pipes — for those use a Doppler radar flowmeter or an ultrasonic open-channel solution instead.
For bidirectional flow keep straight runs of at least 5D on both sides so the flow profile is stable in each direction.
Sewage deposits sludge easily: place the meter close to the pump station so pump scouring keeps the tube clean, and inspect the electrodes periodically.

Bidirectional operation does not change the accuracy specification — the LGF-PA66 holds ±0.5%（DN50-100） of reading in both directions and runs reliably for years with empty-pipe detection enabled. For more information, please visit our product page or contact our technical team.

Frequently Asked Questions

LGF-PA66 Flow Meter: Water Hammer Resistance in Pump Cycling Sites

How Is a 10cm Blind Zone Achieved in Radar Meters?

River Outfall Monitoring: Required Equipment

How Does the Camera on a Radar Level Meter Work?

Sewer Monitoring: Radar Level Meter vs Ultrasonic

Why Use 76-81GHz in a Visual Fusion Radar Level Meter?

Is LGF-PA66 Suitable for Outdoor Installation Without a Shelter?

How to Tighten LGF-PA66 Flange Bolts Without Damaging the Flange?

Does PA66 Moisture Absorption Affect LGF-PA66 Accuracy?

Can LGF-PA66 Measure High-Temperature District Heating Water?

What Is the Minimum Flow Rate of DN15/DN25 LGF-PA66 Flow Meters?

The LGF-PA66 is rated at ±0.2% — how much do field installation conditions affect actual accuracy?

What metering equipment do water-abstraction permit rules require at intakes, and can the LGF-PA66 meet remote-supervision requirements?

How much do gas bubbles from dissolved air affect the accuracy of the LGF-PA66 electromagnetic flowmeter?

Can the LGF-PA66 electromagnetic flowmeter measure bidirectional flow accurately in sewers with frequent backflow?

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