LiquriTech LQ-5Z-H2SO4 Single-Component Sulfuric Acid Concentration Meter
| Brand | LiquriTech |
|---|---|
| Model | LQ-5Z-H2SO4 |
| Origin | Japan |
| Detection Principle | Conductivity-Based Electrochemical Measurement |
| Measurement Range | 0.00–2.00% H₂SO₄ (w/w) |
| Sample Temperature Range | 0.0–40.0 °C |
| Electrode Material | PPS (Polyphenylene Sulfide) Body with Stainless Steel Sensing Elements |
| Temperature Compensation | Automatic (NTC-based, 0–40 °C) |
| Calibration | Zero & Span Calibration via Manual Adjustment |
| Ingress Protection | IP66 |
| Power Supply | 3 × LR03 (AAA) Alkaline Batteries with Auto-Shutdown |
| Electrode Cable Length | 1 m |
| Instrument Dimensions | 38(H) × 75(W) × 180(D) mm |
| Electrode Dimensions | Ø17 × 180 mm |
| Instrument Weight | ~300 g |
| Electrode Weight | ~50 g |
| Compliance | CE-marked for industrial use |
Overview
The LiquriTech LQ-5Z-H2SO4 is a portable, single-component sulfuric acid concentration meter engineered for reliable, on-site electrochemical measurement in industrial process control and environmental monitoring applications. It operates on the principle of solution conductivity—wherein the electrical conductance of an aqueous H₂SO₄ solution correlates predictably with its mass concentration within a defined temperature range (0.0–40.0 °C). Unlike optical or titrimetric methods, this instrument employs a robust, chemically inert PPS-bodied electrode with stainless steel sensing elements, enabling direct immersion into aggressive acidic media without degradation. Its design prioritizes operational stability in humid, splash-prone environments—validated by IP66-rated enclosure integrity—and supports rapid, field-deployable verification of acid strength in rinse tanks, etching baths, scrubber solutions, and wastewater neutralization lines.
Key Features
- Chemically resistant electrode construction using polyphenylene sulfide (PPS) housing and corrosion-resistant metallic sensing surfaces—certified for continuous exposure to ≤2.00% w/w H₂SO₄ at ambient temperatures
- Automatic temperature compensation (ATC) via integrated NTC thermistor, minimizing drift across the full 0.0–40.0 °C operating range
- Dual-point (zero/span) manual calibration protocol compliant with ISO/IEC 17025 traceability requirements when performed with certified reference standards
- IP66-rated instrument body ensures dust-tightness and protection against powerful water jets—suitable for outdoor or semi-industrial deployment
- Low-power operation using three standard AAA alkaline cells, delivering >200 hours of continuous use with intelligent auto-shutdown after 10 minutes of inactivity
- Compact handheld form factor (38 × 75 × 180 mm) with ergonomic grip and high-contrast LCD display optimized for low-light plant-floor readability
Sample Compatibility & Compliance
The LQ-5Z-H2SO4 is validated exclusively for aqueous sulfuric acid solutions containing no suspended solids, organic solvents, or oxidizing agents beyond typical process-grade impurities. It is not intended for use with mixed-acid systems (e.g., H₂SO₄/HNO₃ blends), viscous electrolytes, or non-aqueous matrices. The electrode’s PPS body meets USP Class VI biocompatibility criteria for incidental contact, and the overall system conforms to IEC 61000-6-2 (immunity) and IEC 61000-6-3 (emissions) for industrial environments. While not FDA 21 CFR Part 11–certified as a standalone unit, its calibration logs and measurement records may be incorporated into validated electronic lab notebooks under site-specific SOPs meeting GLP/GMP data integrity requirements.
Software & Data Management
This is a stand-alone, non-networked instrument with no embedded Bluetooth, USB, or cloud connectivity. All measurements are displayed in real time on the built-in LCD screen and retained only visually—no internal memory or data logging capability is provided. Users are expected to manually record readings alongside batch identifiers, timestamps, and calibration status per facility quality procedures. For audit readiness, the device supports generation of calibration certificates when used with NIST-traceable conductivity standards (e.g., KCl solutions at 25 °C), and all calibration events must be documented externally in accordance with ISO 17025 clause 7.7 (measurement traceability).
Applications
- Real-time monitoring of sulfuric acid concentration in printed circuit board (PCB) etching and desmear processes
- Verification of acid strength in metal pickling baths prior to hot-dip galvanizing or electropolishing
- Quality assurance checks for regenerated scrubber liquor in flue gas desulfurization (FGD) systems
- Field validation of dilution accuracy during chemical dosing in municipal wastewater pH adjustment stages
- Preventive maintenance screening of spent battery acid recovery streams in lead-acid recycling facilities
FAQ
Is the LQ-5Z-H2SO4 suitable for measuring concentrated sulfuric acid (>2%)?
No. The instrument is calibrated and validated only for the 0.00–2.00% w/w range. Higher concentrations require dilution to avoid sensor saturation and nonlinearity.
Can the same electrode be used for other acids like HNO₃ or HCl?
No. Each variant (e.g., LQ-5Z-HNO₃, LQ-5Z-HCl) uses electrode-specific calibration curves and temperature coefficients. Cross-use invalidates measurement accuracy.
Does the device support automatic data export to LIMS or SCADA systems?
No. It lacks digital communication interfaces. Integration requires external analog-to-digital converters or manual transcription.
What maintenance is required for long-term reliability?
Rinse the electrode thoroughly with deionized water after each use; store dry in protective cap. Inspect O-rings quarterly for compression set; replace every 12 months or after 500 immersion cycles.
Is third-party calibration service available?
Yes—LiquriTech-authorized service centers in North America and EU offer accredited recalibration against ISO/IEC 17025–compliant conductivity standards, including uncertainty reporting per GUM guidelines.
