Frequently asked questions

An industrial online density meter is an instrument that is directly installed on process pipelines or storage tanks and continuously outputs the density (or concentration) of the medium in real time. Its main differences from laboratory density meters (such as pycnometers and vibrating-tube benchtop models) lie in three aspects:

1. Online density meters perform continuous measurements without the need for sampling;
2. They output 4–20 mA / Modbus signals, allowing direct connection to DCS/PLC systems;
3. Their protection and explosion-proof ratings, as well as their wetted materials, are all designed in accordance with industrial-site standards.

Pisonics offers online density meters based on various principles, including ultrasonic, tuning fork, differential pressure, Coriolis, optical, microwave, and nuclear-source technologies, covering all operating conditions—from slurries to clean liquids.

Short answer: For high solids content and bubbly processes, choose an acoustic impedance density meter (PS7000).

• Acoustic impedance meters excel at resisting fouling and bubbles, with a typical range of 0.5–3.0 g/cm³; their simple mechanical design keeps maintenance costs low. However, for highly abrasive slurries, a wear-resistant tuning fork is recommended.
• Tuning fork concentration meters are highly wear-resistant but susceptible to bubbles; they are relatively expensive, have specific pipe‑diameter requirements, and are easily affected by gas entrainment.

In mining applications such as overflow/slurry from ore beneficiation—where solids content is 30–60% and the slurry is highly abrasive—acoustic impedance meters are by far the most common choice; in cleaner conditions like the downstream section of chemical reactor vessels, tuning fork meters offer a clear advantage.

Selection primarily hinges on four key factors:

1. Medium characteristics—slurry solids content, presence of bubbles, scaling propensity, and corrosiveness;
2. Installation conditions—whether tapping and hot work are permitted, available straight-run pipe lengths, and pipe diameter;
3. Accuracy requirements—trade metering calls for ±0.0005 g/cm³ accuracy (Coriolis), while process monitoring can suffice with ±0.005 g/cm³;
4. Compliance requirements—whether radioactive sources are to be avoided.

Common applications include: bubbly slurries → Pisonics PS7000 ultrasonic acoustic impedance; no‑tapping allowed → Pisonics PS7010 external‑mount; high‑accuracy pure liquids → Pisonics PS7200 Coriolis; severe scaling → Pisonics PS7400 tuning fork; large‑diameter main lines → Pisonics PS7300 differential pressure; waterborne suspensions → Pisonics PS7600 microwave; ultra‑high‑precision optics → Pisonics PS7100 spectroscopy / PS7110 refractometry. For details, refer to the “How to Select a Density Meter” guide.

Accuracy is deviation from the true value — ±0.002 g/cm³ means the reading may run 0.002 above or below actual density. Repeatability is the spread between successive measurements on identical material — ±0.0005 g/cm³ means the trace won't wander beyond that band. For selection: custody transfer and quantitative batching demand accuracy; trend monitoring, process control, and alarm thresholds depend on repeatability. Most sites need both, but repeatability has the bigger day-to-day impact — a noisy reading floods the DCS with false alarms even when long-term accuracy is fine.

Pisonics offers four types of non-nuclear online density meters that can replace traditional instruments using Cs-137/Co-60 radioactive sources:

1. PS7000 ultrasonic acoustic impedance—suitable for bubbly slurry and highly abrasive slurries;
2. PS7010 ultrasonic acoustic attenuation—ideal for conditions where opening the vessel is not permitted, with an external mounting that requires no hot work;
3. PS7400 tuning fork—appropriate for scaling-prone applications and chemical slurries;
4. PS7300 differential pressure—designed for large‑diameter main pipelines (DN200+).

If the project still requires the accuracy afforded by nuclear‑source principles (such as in heavy‑media coal washing), the PS7500 Na22 nuclear density meter employs a source at an exempt activity level (<1,000 KBq) and thus does not necessitate obtaining any radioactive‑source or transport permits.

Pisonics’ mainstream density meters all offer explosion-proof versions:

1. The ultrasonic series (PS7000, PS7010, PS7020) can be optionally equipped with ExdⅡCT6Gb;
2. The tuning fork model PS7400 can be optionally equipped with Ex d ⅡC T6 Gb;
3. The Coriolis model PS7200 can be optionally equipped with Ex d ⅡB T6 Gb;
4. The differential pressure model PS7300 is available in intrinsically safe ExiaIICT6 and flameproof ExdIIBT4 configurations;
5. The spectral model PS7100 and the refractive‑index model PS7110 can be optionally equipped with Ex db ib IIC T6 Gb;
6. The microwave model PS7600 can be custom‑configured for explosion protection.

All explosion‑proof models have passed CNEX explosion‑proof certification. When placing an order, please specify the applicable hazardous area classification (Zone 0/1/2) and the temperature class.

The standard model delivery time is typically 2–4 weeks.

Customized models (featuring special wetted materials such as 2205 duplex stainless steel, Hastelloy, or titanium; non-standard measurement ranges; special linings; explosion-proof variants; sanitary process connections, etc.) have a delivery time of 4–10 weeks.

Bulk orders or urgent projects can be expedited.

All series support process customization: probe length, process connections (flanges to ANSI, DIN, and JIS standards, clamps, and threads), cable length, display language, and communication protocols (Modbus, HART, Profibus, and 4–20 mA).

Before placing an order, we dispatch an engineer to verify the operating conditions and provide a written selection proposal.

In industrial environments, under normal operating conditions, it is recommended to perform zero/span verification and calibration every 12 to 18 months. The specific frequency depends on the process conditions: for clean, stable media (such as finished oil or syrup), the interval can be extended to 24 months; for media containing abrasive particles or at elevated temperatures, calibration at 6 to 12-month intervals is advised.

Calibration methods:

1. Manual sampling and laboratory analysis, followed by comparison with the instrument readings and adjustment of the zero/span offsets;
2. In‑place calibration using a reference solution (e.g., a brine solution of known concentration);
3. Remote support—access the Pisonics remote diagnostic system via RS‑485 or 4G, where engineers can analyze the data online and provide guidance for adjustments.

The Pisonics headquarters offers factory‑level traceable calibration using temperature‑controlled laboratory equipment.

Work through process first, installation second, instrument last — six steps cover most cases:

1. Confirm the fluctuation is real — take 3 to 5 manual samples in parallel; if lab values swing too, the process itself is moving (feed changes, agitation, crystallization), not the meter;
2. Check for bubbles — aeration, pump suction vacuum and cascading inflows all shake the reading. Bubble-sensitive principles (tuning fork, DP, single-frequency ultrasonic) suffer most; gassy media are better served by acoustic impedance with Chirp processing (PS7000);
3. Check full-pipe condition and mounting location — a partially filled pipe, phase separation, or mounting too close to elbows and valves (less than 5D upstream / 2D downstream) introduces turbulence noise;
4. Check fouling and wear — scale buildup shows as slow drift followed by jumps; abrasive slurry wears contact sensors. Inspect visually through the access port;
5. Check electrical — 4-20 mA loop load (max 500 ohm), ground loops, VFD interference; on remote versions ground the cable shield at one end only;
6. Check settings — damping or filter time set too short amplifies normal process noise; verify calibration factors against manual samples if drift is suspected.

If readings are still abnormal after all six steps, connect via RS485 / 4G to the Pisonics remote diagnostic system and an engineer will review the raw signal online.

Manual sampling comparison is the gold standard — done wrong, it blames a healthy instrument. The correct procedure:

1. Sample next to the meter — within 1 to 2 m downstream of the measuring point; farther away, real concentration gradients get mistaken for meter error;
2. Synchronize records — note the meter reading at the moment of sampling (or use the built-in data log timestamps); slurry concentration shifts within minutes;
3. Take 3 to 5 samples — a single point has no statistical meaning; compare averages and watch the spread;
4. Mind the temperature — lab temperature differs from process temperature; convert density to the same temperature before comparing (the meter reading is usually already temperature compensated);
5. Judge correctly — deviation within instrument accuracy (for example 1% FS) plus sampling error is normal; a systematic offset (same direction, stable size) needs only a zero/span adjustment, not a factory return.

Reference: at a potash plant in Qinghai, two weeks of daily sampling against a PS7000 held deviations at 0.5% to 0.8%, including through concentration peaks.

Supported; products have been exported to countries including Southeast Asia (Vietnam, Indonesia, Malaysia), the Middle East (Saudi Arabia, UAE), Africa (South Africa, Zambia), South America (Chile, Peru), and the Commonwealth of Independent States (Russia, Kazakhstan).

Major international certifications: CE certification (European Union), ATEX/IECEx explosion-proof certification (for select models), and RoHS certification.

Supplied with EN 10204 3.1 material certificates, an English-language user manual, installation and commissioning videos, and remote technical support (including multilingual engineers who speak Vietnamese, Spanish, Russian, and other languages).

There is no list price for inline density meters — the same model can vary 2 to 3 times in price depending on configuration. The final figure is driven by six factors:

1. Measuring principle — tuning fork and differential pressure designs are the most economical; ultrasonic and microwave sit mid-range; Coriolis and spectroscopic (with modeling) are positioned higher. Nuclear gauges add ongoing compliance costs on top of the instrument itself.
2. Wetted materials — 316L is the baseline; corrosive media require 2205 duplex, Hastelloy C-276, titanium or full PTFE lining, and abrasive slurries call for ceramic sensor faces. Materials are the single biggest price lever.
3. Explosion proofing and certification — Ex d IIC T6 Gb housings, sanitary builds (Tri-Clamp, mirror polish) and CE / ATEX export certification all add cost.
4. Pipe size and process connection — DN50 to DN1000 is standard; larger bores and non-standard flanges are custom work.
5. Mounting and options — integral vs remote electronics (signal up to 500 m), 4G telemetry, remote displays.
6. Customization and modeling — spectroscopic multi-component analysis needs an MLR model built from your medium samples (2 to 4 weeks); non-standard ranges and insertion lengths are quoted per case.

The fastest route to a real number: send your process datasheet (medium, concentration range, temperature, pipe size, hazardous-area class) to a Pisonics engineer — a written model selection and quotation comes back within 2 working days.

Both are ultrasonic-based, but their underlying physical principles and applicable operating conditions differ significantly:

The PS7000 employs the acoustic impedance method—using a single probe for both transmission and reception to measure the reflection characteristics of ultrasonic waves at the interface. Its advantages include strong resistance to bubble interference (thanks to the Chirp broadband algorithm) and broad media adaptability (even for solid–liquid two-phase slurries); installation is flanged direct insertion, requiring a hole to be drilled.

The PS7010 uses the acoustic attenuation method—employing a through-beam configuration with one transmitting and one receiving probe to measure the energy attenuation after wave penetration. Its advantages are non-invasive external mounting without drilling (in certain applications), a simple and reliable principle, and high accuracy for clean slurries; its disadvantages are sensitivity to bubbles and stringent requirements for pipe wall thickness in external mounting.

A simple guideline: if bubbles are present → choose the PS7000; if no drilling is permitted → choose the PS7010; for standard cases, either model can be selected based on specific needs.

The PS7000 is an acoustic-impedance ultrasonic density meter with no radioactive source whatsoever. No radiation license is required. It uses only piezoelectric transducers to send and receive ultrasonic signals — the same physical principle as medical and NDT ultrasound.

If you're currently using a Cs-137 / Co-60 source-based meter and want to remove the regulatory burden, PS7000 is a drop-in alternative. We also offer the PS7500 gamma meter, which uses an exempt-activity Na-22 source (< 1000 KBq) — also requires no radiation license.

View product · Slurry density meter →

Yes.

The PS7000 employs a linear frequency-modulated (Chirp) acoustic impedance algorithm—after transmitting a broadband ultrasonic pulse, the host unit analyzes the echo signal in the frequency domain, and multiple-reflection interference caused by bubbles is identified and eliminated by the algorithm. This is the core difference between the PS7000 and conventional reflective ultrasonic density meters: traditional single-frequency reflection is highly sensitive to bubbles, whereas the PS7000’s Chirp algorithm is virtually immune to them.

At the gypsum discharge line of an absorption tower in a thermal power plant in Inner Mongolia (under conditions of continuous air oxidation that generate dense bubbles), the PS7000 has been operating stably for several years after replacing the original tuning fork concentration meter.

View product · Slurry density meter →

The installation requirements for the PS7000 flanged direct-insertion type are as follows:

1. Straight-run pipe sections: ≥5D (upstream) + 2D (downstream), where D is the nominal pipe diameter;
2. The installation point must operate with a full pipe to avoid stratification of gas and liquid phases;
3. The applicable pipe sizes range from DN50 to DN1000 (larger sizes can be customized);
4. The flanges are compatible with ANSI/DIN/JIS standards;
5. In highly abrasive conditions, it is recommended to use a 316L probe with special ceramics or a 2205 duplex stainless steel probe;
6. In strongly corrosive environments, a PTFE-lined option is available.

If the pipeline does not allow for tapping, please consider the PS7010 clamp-on type instead.

View product · Slurry density meter →

On purchase price alone, ultrasonic and nuclear gauges sit in a similar bracket. The gap opens over 5 to 10 years of ownership.

Hidden cost list of a Cs-137 / Co-60 nuclear gauge:

• Radiation safety licensing and annual reviews, plus operator training and certification;
• Licensed transport and installation filing for the source;
• Dose monitoring and record keeping during service;
• Source replacement as activity decays (purchase, transport, commissioning, return of the old source);
• End-of-life disposal of the spent source — often the single largest bill.

PS7000 acoustic-impedance ultrasonic gauge: no radioactive source and no permits of any kind; non-contact sensor with zero wear and zero clogging, sensor life of 5 years or more, virtually maintenance free with no consumables. Power plant, potash and iron ore sites have run 2+ years at near zero maintenance.

Bottom line: on a 5-year basis the total cost of ownership of the PS7000 is typically far below a nuclear gauge. Where a nuclear principle is genuinely required (such as dense-medium coal washing), the PS7500 with an exempt-activity Na-22 source needs no license, though the roughly 2.6-year half-life still implies periodic source renewal.

View product · Slurry density meter →

The PS7010 external clamp-on type indeed requires no pipe openings, but it does have specific application conditions. Applicable operating scenarios include:

1. Uniform pipe wall material (carbon steel, stainless steel, or copper alloys are all acceptable; plastic or rubber-lined pipes are not suitable);
2. Stable pipe wall thickness (variations in the thickness of internal scale can affect acoustic attenuation readings);
3. Low gas bubble content in the medium (acoustic attenuation is sensitive to bubbles; for bubbly conditions, we recommend the PS7000);
4. Recommended pipe diameters: DN50–DN500.

Installation method: secured with steel band clamps and coated with coupling agent, completed in a few minutes. We also offer on-site ultrasonic coupling tests, with a feasibility report issued within two working days.

View product · Acoustic attenuation density meter →

The core advantage of the PS7020 sound-velocity method is that it is “unaffected by the appearance of the medium”:

Refractometers rely on light passing through the sample and are severely affected by liquid color, turbidity, and bubbles—dark beverages, brewing liquids containing suspended particles, and bubbly fermentation mash often cause refractometer readings to be inaccurate.

The PS7020 calculates sound velocity by measuring ultrasonic wave propagation time, and is completely independent of color, transparency, electrical conductivity, vibration, noise, and flow rate. Its accuracy is ±0.0005 g/cm³ (density) / 0.5‰ (concentration).

However, the PS7020 is not suitable for extremely dilute solutions—in such cases, the PS7110 refractometer offers higher accuracy.

View product · Sound Velocity Concentration Meter →

Yes. The PS7100 employs a full-spectrum UV-Vis-NIR absorption method (200–1,700 nm) combined with an MLR multivariate linear regression algorithm, enabling the simultaneous output of concentrations for multiple components in a single measurement.

Typical applications:

1. In chlor-alkali sodium hypochlorite production, it simultaneously measures effective chlorine and free alkali NaOH (model R² > 0.99);
2. Dual-component analysis of mixed acid solutions (HCl + H₂SO₄);
3. Semiconductor wet etching solutions (HF + HNO₃);
4. Simultaneous monitoring of sugar content and alcohol content in pharmaceutical fermentation broths.

The multi-component capability requires preliminary modeling; Pisonics will develop a dedicated MLR model in its headquarters laboratory based on the customer’s media samples, with a modeling cycle of 2–4 weeks.

View product · Spectroscopic concentration meter →

View product · Refractive concentration meter →

The PS7300 offers three installation configurations:

A—Straight‑tube insertion—vertically inserted through a single hole in the tank roof; this is the most common method and is suitable for atmospheric‑ or low‑pressure storage tanks without agitation or with stable liquid levels (such as finished‑oil tanks and urea solution tanks).

B—Bent‑joint insertion—inserted through a single hole and then bent to a specified depth inside the tank, bypassing agitators or heating coils; this is ideal for large chemical polymerization reactors and MVR evaporation crystallizers.

C—Side‑mount installation—two openings on the tank sidewall, with the diaphragm directly facing the liquid column; this is appropriate for stirred reaction vessels, oil‑gas field three‑phase separators, and horizontal pipeline applications.

Simple guidelines: vertical installation with no obstructions → A; obstacles inside the tank requiring bypass → B; feasible with two side‑wall openings → C.

All three methods have a measurement range of 0–1.0/2.0/3.0 g/cm³, with a resolution of 0.001 g/cm³.

View product · Pipeline Differential Pressure Density Meter →

PS7400 supports flange / tri-clamp / threaded / cable-separated process connections; F1~F6 accessories (bracket, bypass loop, flow cell, flushing port, flanged seat, protective shield) cover inline pipes, open tanks, agitated tanks, scaling media. Insertion lengths: 100 / 150 / 200 / 300 / 400 mm. Selection: inline pipe — insertion = 1/3 to 1/2 pipe diameter, away from wall turbulence; open/storage tank — mid-liquid, away from surface waves and bottom sediment; agitated tank — beyond 1.5× the agitator radius.

View product · Online tuning fork density meter →

View product · Na22 density meter →

The physical basis of microwave measurement lies in differences in dielectric constants: the dielectric constant of water molecules is approximately 80, while that of most solids is around 2 to 10—more than a tenfold difference.

The PS7600 precisely calculates a material’s moisture content, suspended solids concentration, density, and Brix by measuring the phase shift and amplitude attenuation of microwaves as they pass through the medium. This substantial dielectric contrast gives the PS7600 extremely high sensitivity in wet conditions, with typical repeatability better than ±0.01%.

Optimal applications include coal slurry in washing plants, black liquor in papermaking, evaporation and crystallization in sugar production, and concentration monitoring in the food and beverage industries.

Not suitable for pure organic liquids (such as diesel or pure alcohol); in such cases, it is preferable to use the PS7020 sound‑velocity method or the PS7110 refractometer.

View product · Microwave concentration/density meter →

Typical Pisonics configurations for FGD:

• Limestone slurry tank / absorber recirculation → PS7400 tuning fork, excellent scaling resistance, range 1.0–1.4 g/cm³ covers all normal operating conditions
• Gypsum slurry / discharge pump downstream → PS7300 differential pressure, cost-effective for large-bore main lines
• FGD wastewater (high chloride) → PS7010 ultrasonic attenuation, clamp-on install removes the corrosion-protection problem

Final selection depends on your specific PFD, pipe sizes, temperature, and SO₃ content. Send us your process parameter sheet and we'll return a written sizing proposal within 2 business days.

View industry · Power Emission Control →

Yes.

The Pisonics standard tuning fork density meter PS7400 has a measurement range of 0–150°C, and the standard ultrasonic concentration meter PS7000 covers 0–120°C, which can accommodate most slurry-based hydrometallurgical processes.

For extreme conditions such as high-pressure acid leaching (HPAL) at temperatures above 200°C, we offer custom high-temperature models with titanium alloy or Hastelloy wetted parts, paired with remote transmitters to isolate the electronic components.

Common temperature ranges include: ambient‑temperature slurry (≤ 60°C) / heated flotation (60–90°C) / atmospheric leaching (90–110°C) / high‑pressure leaching (150–250°C) / autoclaves (≥ 250°C, requiring special customization). Please specify the maximum operating temperature when requesting a quote.

View industry · Non-ferrous Mining →

Typical measurement point configurations for FGD systems:

1. Limestone slurry tank / pulp-making tank outlet → PS7000 acoustic impedance (strong anti-fouling);
2. Absorption tower gypsum slurry / discharge pump main line → PS7000 ultrasonic acoustic impedance (bubble-resistant, non-contact);
3. Flue-gas desulfurization wastewater (chlorine-corrosive) → PS7000 acoustic impedance or PS7400 titanium/ Hastelloy tuning fork;
4. AFT tower high-concentration slurry → PS7000 or PS7400 titanium/ Hastelloy tuning fork;
5. SCR denitrification ammonia water / urea solution → PS7400 tuning fork (medium accuracy) or PS7100 spectroscopy (multi-component).

View industry · Power Emission Control →

Yes. The Pisonics density meter offers tiered temperature and corrosion solutions.

Temperature ratings:

• Normal-temperature slurry ≤ 60°C—standard configuration;
• Heated flotation 60–90°C—select the standard model;
• Atmospheric leaching 90–110°C—select the high-temperature model;
• High-pressure acid leaching (HPAL) 150–250°C—requires customization (use titanium or Hastelloy for wetted materials, and equip with a remote transmitter to isolate the electronic components);
• Autoclaves ≥ 250°C—special customization.

Corrosion-resistant solutions:

• Weak corrosion → 316L;
• Strong acids and alkalis → 2205 duplex stainless steel, Hastelloy C‑276, titanium, or PTFE lining;
• High-abrasion slurry → ceramic probe + PTFE lining.

View industry · Non-ferrous Mining →

Hygienic requirements for food and beverage production:

1. Wetted materials — 316L stainless steel, polished (Ra ≤ 0.4 μm), PTFE, sapphire;
2. Process connections — sanitary clamp (Tri-Clamp), ISO food-grade flanges;
3. CIP/SIP cleaning — resistant to 90°C hot water, chemical cleaning with 3% NaOH/3% HNO3, steam sterilization at 134°C;
4. Dead‑free design;
5. Compliance certificates — FDA 21 CFR, EHEDG, and 3-A certification (for select models).

Pisonics hygienic‑grade versions: PS7400 tuning fork (clamp connection + 316L polishing + PTFE coating), PS7110 refractive index meter (sapphire prism + sanitary clamp), PS7020 sound velocity method (PTFE wetted parts), PS7210 Coriolis mass flow meter (sanitary clamp).

View industry · Food / Brewing / Sugar →

The primary consideration for measuring strong acids and strong bases is the wetted-material compatibility:

1. Concentrated sulfuric acid (98%) → PS7400 tuning fork (PTFE coating + titanium tines) or PS7110 refractometer (sapphire prism resistant to acids);
2. Sodium hydroxide (NaOH 32% / 48%) → PS7400 tuning fork (PTFE coating + 316L stainless steel) or PS7100 spectrometer (fiber-optic separation, with the main unit housed in a safe area);
3. Hydrochloric acid (HCl) → PS7100 spectrometer (no wetted components) or PS7110 refractometer;
4. Mixed acids (H2SO4 + HNO3) → PS7100 spectrometer (MLR dual-component simultaneous modeling);
5. Hydrofluoric acid (HF) → PS7100 spectrometer or PS7110 refractometer (sapphire resistant to HF).
6. The simultaneous measurement of both effective chlorine and free alkali in chlor-alkali sodium hypochlorite is a signature application case for the PS7100.

View industry · Chemical / Fine Chemical →

Yes. Pisonics offers GMP-compliant versions for the pharmaceutical industry:

1. Wetted materials—316L electropolished, PTFE, and sapphire;
2. Process connections—sanitary Tri-Clamp clamps (DIN 32676 / ISO 2852);
3. Surface finish—Ra ≤ 0.4 μm mirror polish;
4. Validation documentation—IQ/OQ validation documents, material traceability certificates (EN 10204 3.1), and surface roughness reports are provided upon shipment;
5. CIP/SIP compatibility—withstanding steam sterilization at 134°C.

Typical applications: sugar/alcohol concentration in fermenter external circulation lines (PS7110 refractive index), concentration during injection solution preparation (PS7210 Coriolis), API crystallization (PS7300 differential pressure), and PAT process analysis (PS7100 spectroscopy). It has also passed a 21 CFR Part 11 audit.

View industry · Pharma / Biotech →

The core requirements for density meters in custody‑transfer applications are as follows:

1. Absolute accuracy—typically ≤ ±0.001 g/cm³, with high‑standard projects requiring ≤ ±0.0005 g/cm³;
2. International certifications—compliance with metrological regulations such as OIML R117, API MPMS 11.1, and the MID;
3. Long‑term traceability—zero drift within 12 months ≤ 0.0005 g/cm³, traceable to the national metrology standard;
4. Temperature and pressure compensation—built‑in PT100 for real‑time temperature and pressure correction;
5. Data storage—cyclic storage of thousands of transfer records;
6. Explosion protection—petroleum product transfer areas generally require Exd II B T4 or higher.

We recommend: PS7400 tuning fork (for refined oil / liquefied gas / marine fuel) and PS7210 Coriolis (for high‑precision measurement).

View industry · Oil & Gas / Petrochemical →

Challenges in water treatment and sludge processes:

1. Diverse impurities—fibers, hair, plastic fragments, and other filamentous materials that can easily wrap around contact-type instruments;
2. Serious scaling—phosphate and calcium ions in the sludge dewatering stage lead to solid deposits adhering to probes;
3. Corrosiveness—wastewater pH fluctuates widely (4–10);
4. High gas content—abundant bubbles in the aeration section interfere with conventional ultrasonic and refractometric instruments.

Recommended solutions: PS7000 ultrasonic acoustic impedance (for aeration tanks with numerous bubbles), PS7010 external‑mounted ultrasonic (for non‑perforable older pipelines, with zero hair entanglement), PS7400 tuning fork with PTFE coating (for the sludge dewatering stage, resistant to scaling), PS7600 microwave (for advanced dewatering of municipal sludge).

View industry · Water & Wastewater →

It is necessary. AI data center liquid cooling (cold‑plate and immersion types) typically uses aqueous solutions of ethylene glycol (EG) or propylene glycol (PG), with concentrations ranging from 30% to 50%. The importance of precise concentration control: too low a concentration → insufficient freezing point, posing a risk of pipe freezing in northern winters; too high a concentration → increased viscosity, leading to higher pump energy consumption and reduced heat transfer efficiency.

Drift sources:

1. Dilution due to system makeup water;
2. Local concentration increases as the evaporative section under high load preferentially removes water;
3. Slow oxidation and decomposition of ethylene glycol.

Recommendation: PS7400 tuning fork density meter (density accuracy ±0.001 g/cm³, convertible to concentration accuracy ±0.5%), installed in the main loop of the heat exchanger.

View industry · Data Center / HVAC Liquid Cooling →

The core electrolyte in the lithium‑battery copper‑foil electroplating process consists of copper sulfate (CuSO4), dilute sulfuric acid (H2SO4), and additives; precise concentration control directly determines the copper foil’s thickness uniformity, grain size, and tensile strength.

Measurement challenges:

1. The medium is highly corrosive (H2SO4 + Cu2+);
2. The concentration fluctuation range is very narrow (CuSO4 typically 60–80 g/L, requiring control within ±2 g/L);
3. The site temperature varies significantly (25–55°C);
4. The presence of trace additives (gelatin/SPS) affects certain principle‑based instruments.

Recommendations:

1. PS7100 spectroscopic method—MLR multicomponent modeling enables simultaneous measurement of Cu2+ concentration, H2SO4 concentration, and additive concentration;
2. PS7020 sound velocity method—single‑component density accuracy of ±0.0005 g/cm³, with a PTFE lining for acid resistance.

View industry · New Energy / Battery Electrolyte →

Challenges posed by the environment of dredging vessels (cutter suction dredgers, trailing suction hopper dredgers, and sand‑suction vessels) to instrumentation:

1. Continuous vibration—vibration from the main engine, mud pump, and cutter ranges from 0.5 to 5 g;
2. Salt‑mist corrosion—seawater aerosols severely corrode the enclosures of electronic instruments;
3. Coarse‑sand abrasion—the slurry contains coarse sand with particle sizes ≤ 50 mm;
4. Cross‑border operations—nuclear‑source density meters are subject to cumbersome approval procedures for international transport licenses.

Recommended: PS7000 ultrasonic acoustic impedance concentration meter—

1. Flange‑mounted direct‑insertion design with a non‑contact probe, eliminating wear;
2. The ceramic probe withstands continuous erosion by sand and gravel, with a service life ≥ 5 years;
3. IP65 rating; explosion‑proof ExdⅡCT6Gb optional;
4. Completely non‑nuclear;
5. 4G module optional, enabling the fleet headquarters to monitor all operating vessels in real time.

View industry · Dredging Vessels →

The core measurement requirements for paper‑making black liquor (digestion waste liquor, containing lignin and alkali) and white liquor (a mixture of NaOH and Na2S) are as follows:

concentration monitoring, recovery efficiency, and energy‑saving control.

Black liquor conditions: high viscosity (500–3,000 cP), dark color (optical methods are not applicable), temperature 70–150°C, and presence of fine particles.

We recommend the PS7600 microwave density meter (dielectric sensitivity to water allows measurement of solids content and concentration) or the PS7020 sound velocity method (immune to color interference).

White liquor conditions: strong alkaline corrosion, temperature 80–120°C.

We recommend the PS7110 refractometer (with a sapphire prism resistant to NaOH) or the PS7400 tuning fork (with PTFE coating). For green liquor (the precursor to recovered white liquor), refer to the black liquor solution.

View industry · Pulp & Paper →

The mud–water balance density measurement in tunnel boring machines is a key parameter for stabilizing the excavation face.

Typical operating conditions:

1. Inflow slurry density: 1.05–1.20 g/cm³;
2. Outflow slurry density: 1.20–1.40 g/cm³ (containing cuttings);
3. The slurry contains coarse sand and gravel with particle sizes ≤ 50 mm;
4. Severe on-site vibration, high humidity, and heavy condensation.

We recommend the PS7000 ultrasonic acoustic impedance concentration meter:

1. Flanged direct‑insertion design with a non‑contact probe, eliminating wear;
2. Sapphire probe resistant to sand and gravel erosion;
3. Chirp algorithm suppresses bubble interference;
4. IP65 rating; explosion‑proof ExdⅡCT6Gb optional;
5. 4–20 mA + Modbus connectivity to the TBM’s main PLC, enabling real‑time feedback of the inflow–outflow density difference to support chamber pressure adjustment.

View industry · Tunnel Boring (TBM) →

In semiconductor wet‑process operations (etching, CMP, cleaning), ultrapure chemicals (HF, H2SO4, H3PO4, KOH, etc.) are used, placing the following requirements on density meters:

1. Wetted materials must ensure zero metal ion contamination—sapphire, PTFE, and Teflon‑PFA.
2. High concentration accuracy is required (a deviation of ≤ 0.1 wt% can affect product yield).
3. Simultaneous measurement of multiple components is needed (e.g., a mixed etchant of HF + HNO3 + H2SO4).
4. A hygienic surface finish is essential to prevent particle contamination.
5. Long‑term stability is critical, as semiconductor production lines operate 24/7 without downtime.

Recommended models: PS7100 spectral method (multi‑component MLR modeling, no wetted body, sapphire window); PS7110 refractometer (sapphire prism resistant to HF); PS7020 sound velocity method (PTFE wetted parts, highly acid‑resistant).

View industry · Semiconductor / Wafer FAB →