Portable dissolved oxygen analyzer

Introduction

A portable dissolved oxygen analyzer is a portable instrument used to measure the dissolved oxygen concentration in the water and the other liquids, and it is used in the environmental monitoring, the aquaculture, the wastewater treatment, and the many other applications for the field and the on-site measurement. The portable dissolved oxygen analyzer consists of a dissolved oxygen sensor, which may be an electrochemical or an optical (luminescent) sensor, a signal processing circuit, a display, and the battery, and it measures the dissolved oxygen concentration, expressed in milligrams per liter or in the percent saturation, with the automatic temperature compensation and the salinity and the pressure corrections, and it displays the value, with features such as the calibration, the data logging, and the waterproof construction; the portable dissolved oxygen analyzer is designed for the field and the portable use, with a compact and a rugged construction, and it is used for the measurement of the dissolved oxygen in the aquaculture ponds, in the rivers and the lakes, in the wastewater, in the groundwater, in the industrial processes, for the monitoring of the water quality, for the assessment of the oxygen for the aquatic life, and for many other applications; the portable dissolved oxygen analyzer provides a rapid and a reliable measurement of the dissolved oxygen in the field. Portable dissolved oxygen analyzers are used by the aquaculturists, by the environmental monitors, by the wastewater operators, by the researchers, and for many other applications. With their portability, portable dissolved oxygen analyzers are essential for the on-site dissolved oxygen measurement.

Portable Dissolved Oxygen Analyzer LPDOA-T2011

Portable Dissolved Oxygen Analyzer ensures precise measurement of dissolved oxygen concentration with indication error of 0.01µS/cm. It features salinity compensation function, which al...

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Portable Dissolved Oxygen Analyzer LPDOA-T2010

Portable Dissolved Oxygen Analyzer offers a measuring range of 0.00 to 20.0 mg/L, with a resolution of 0.01/0.1 mg/L or 0.1%/1% (), ensuring precise and reliable detection of oxygen leve...

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Standards

ISO 19229:2019-Gas analysis-Purity analysis and the treatment of purity data

ASTM D7607/D7607M-19-Standard Test Method for Analysis of Oxygen in Gaseous Fuels (Electrochemical Sensor)

ISO 12039:2019-Stationary source emissions-Determination of CO, CO2 and O2 in flue gas-Performance characteristics of automated measuring systems

Complies with the above standards, but is not limited to them.

Features

1. Portable dissolved oxygen analyzer for field measurement of oxygen concentration in water and aqueous solutions.

2. Handheld DO meter with electrochemical (galvanic/polarographic) or optical (luminescent) sensor for on-site testing.

3. Suitable for aquaculture, environmental monitoring, water treatment, wastewater, beverage and field research.

4. Includes meter body, DO probe/sensor, calibration supplies, batteries, carrying case and operation manual.

5. Supports dissolved oxygen measurement in mg/L (ppm) or percent saturation, with automatic temperature compensation.

FAQ

Q1: What testing scenarios is this analyzer mainly applied to?

A: The portable dissolved oxygen (DO) analyzer is used in aquaculture, environmental monitoring, water treatment, wastewater, beverage, agriculture, and field research to measure the concentration of dissolved oxygen in water on-site, providing immediate data for assessing water quality, aquatic life support, treatment efficiency, and process control. It supports aquaculture (fish/shrimp ponds - DO is the most critical water quality parameter; monitor pre-dawn (lowest DO) and afternoon; >5 mg/L for most fish, >4 for shrimp; early morning DO crash is major killer; portable allows walking pond-to-pond), environmental monitoring (rivers, lakes, streams, groundwater, estuaries - field measurement (DO changes rapidly with temperature/agitation; must measure on-site, cannot transport sample), wastewater treatment (influent/effluent, aeration basins (control aeration energy), activated sludge (DO setpoint 2 mg/L), discharge compliance (permit limits)), water treatment (drinking water (DO affects taste, corrosion, treatment processes; monitor after aeration), process water), beverage (brewing (wort aeration, dissolved oxygen in beer (low DO = shelf life; measure post-fermentation, packaging), wine, soft drinks), agriculture (irrigation water, soil solution, hydroponics/aquaponics (DO in nutrient solution for root health)), and field research (ecology, limnology, oceanography, water quality surveys). Portable design allows measurement at the sample source (critical for DO - oxygen levels change with temperature, pressure, agitation, and biological activity during transport; field measurement is standard per ISO 5814, ASTM D888). Sensor types: electrochemical (galvanic or polarographic Clark electrode - membrane, electrolyte, consumes oxygen, needs flow/stirring, regular membrane/electrolyte maintenance) or optical (luminescent/fluorescence quenching - no electrolyte, no oxygen consumption, no flow dependence, low maintenance, more stable, longer sensor life; recommended for field use).

Q2: What standards does the analyzer comply with?

A: The portable dissolved oxygen analyzer follows relevant ISO, ASTM, EPA and GB/T standards including ISO 5814 (water quality - determination of dissolved oxygen - electrochemical probe method), ISO 5813 (water quality - determination of dissolved oxygen - iodometric method (Winkler) - reference method), ASTM D888 (standard test methods for dissolved oxygen in water - parts A (electrochemical), B (Winkler)), ASTM D5462 (standard test method for dissolved oxygen in water (on-line/field)), EPA Method 360.1 (dissolved oxygen by membrane electrode), EPA Method 400-F (field measurement), and GB/T standards for dissolved oxygen meters. The hardware complies with applicable analytical instrument standards and EMC (IEC 61326), IP rating (IP67 for field/portable). Calibration uses air-saturated water or water-saturated air (100% saturation) and zero-oxygen solution (sodium sulfite + cobalt chloride, or nitrogen-purged water) per ISO 5814/ASTM D888. For wastewater discharge, follow EPA/NPDES permit methods. For aquaculture, follow FAO guidelines and best management practices. For beverage/brewing, follow ASBC (American Society of Brewing Chemists) or MEBAK methods. For regulated labs, follow ISO 17025 and maintain calibration records.

Q3: What is the warranty period for the whole analyzer and key components?

A: The whole portable DO analyzer is covered by a 12-24 month warranty (field instruments often 2 years). The meter body, electronics, display, and temperature sensor are covered, while DO sensor/probe (wear part - electrochemical: membrane/electrolyte degrades 6-12 months, anode/cathode consumes; optical: lumiphore degrades 2-5 years), calibration solutions (consumable - sodium sulfite zero solution), membranes/electrolyte (electrochemical only - replacement kits), and batteries (portable) are consumables/accessories. Damage from improper use, probe fouling (biofilm, algae, sediment on membrane - clean regularly; field water is high-fouling), dry storage of electrochemical probe (must store with moist sponge or per manufacturer - drying damages membrane/electrolyte), dropping (portable units), liquid ingress into meter body (if not IP-rated), or unauthorized repair is excluded. Extended warranty and service contracts (calibration, sensor replacement) may be available. Electronics last 5-10 years; electrochemical sensors need membrane/electrolyte replacement every 6-12 months and full probe replacement 1-3 years; optical sensors last 2-5 years.

Q4: Is this device difficult to operate? Is professional training required?

A: Operation is straightforward for basic DO measurement. No professional training required for routine field use, but proper calibration and sensor maintenance are critical for accuracy (DO is sensitive to temperature, pressure, and sensor condition). We provide operation manuals. Proper setup (insert batteries (portable) or charge, turn on, allow warm-up (15-30 min for electrochemical stabilization; optical is faster), connect probe (ensure cable secure, no damage), prepare calibration (air calibration: hold probe in air with water-saturated atmosphere (wet sponge in calibration chamber, or air-saturated water; enter altitude/barometric pressure for correction (DO solubility decreases with altitude); or Winkler/azide calibration for high accuracy), zero calibration (sodium sulfite solution (2% Na2SO3 + cobalt chloride catalyst) or nitrogen-purged water; for high accuracy or low-DO measurements; optical sensors may not need zero routinely), calibration (single-point air calibration (most common for field): rinse probe, gently shake off excess water, hold in humid air (not direct airflow, not direct sun), wait for stable reading, set to 100% saturation or mg/L based on temp/altitude; two-point (air + zero) for best accuracy, especially low DO; calibrate before each use or at start of day (field calibration drifts), sample measurement (collect sample or lower probe directly into water (rinse probe with sample water first), immerse probe fully (ensure no air bubbles on membrane/cap; for electrochemical: gently stir or move probe (Clark electrode consumes oxygen - stagnant water gives low readings; optical: no stirring needed), wait for stable reading (30-60 sec; electrochemical needs flow), record DO (mg/L or % saturation) and temperature (always report temp - DO solubility is temp-dependent), for wastewater/aeration: probe directly in basin (stirring natural), for deep water: use cable to lower probe to desired depth (profile measurement), post-measurement (rinse probe thoroughly with clean water (remove sediment, biofilm), clean if fouled (soft brush, mild detergent; do not scratch membrane), store properly (electrochemical: with moist sponge in cap or storage solution; optical: dry or per manufacturer; never let electrochemical membrane dry out), maintenance (daily: rinse probe after use, check calibration (air check), weekly: clean probe (field use = high fouling), inspect membrane/cap (electrochemical: replace if damaged, fouled, or electrolyte depleted; optical: inspect cap for scratches/damage), monthly: full calibration (air + zero), replace membrane/electrolyte (electrochemical: every 1-3 months depending on use/fouling), sensor replacement (electrochemical: 1-3 years; optical: 2-5 years or when readings unstable/drift), troubleshooting (readings unstable/drifting (probe fouled (biofilm, sediment - clean), air bubbles on membrane (remove), electrochemical needs stirring (stir gently), sensor aging (replace), low battery - clean, remove bubbles, stir, replace sensor, charge), DO readings too low (electrochemical not stirred (oxygen depletion at membrane - stir), probe not equilibrated, calibration at wrong altitude, membrane fouled, zero drift - stir, wait, enter altitude, clean, recalibrate), DO readings too high (air bubbles on membrane, probe in sunlight (algae photosynthesis produces O2 - shade probe), calibration error, temperature compensation off - remove bubbles, shade, recalibrate, verify ATC), sensor not reading (cable loose/disconnected, membrane damaged (electrochemical), probe failed, battery low - check cable, replace membrane/probe, charge), meter not turning on (batteries dead, corrosion in compartment, power issue - replace batteries, clean contacts, service), and safety (WATER/ELECTRICAL (portable meter near water - do not immerse meter body (only probe), ensure IP rating for field use; battery-powered is safer than mains), CHEMICAL (zero solution (sodium sulfite - reducing agent, irritant; cobalt chloride - toxic (do not ingest, wear PPE); calibration solutions - handle per SDS, dispose properly), BIOLOGICAL (field water may contain pathogens, algae toxins - avoid ingestion, wash hands, wear gloves if wastewater), ENVIRONMENT (do not discard calibration solutions into water bodies - dispose properly), SUNLIGHT/HEAT (do not leave meter in direct sun (overheats, damages display; optical sensors can be affected by bright light - shade probe), handle electrochemical probe carefully (membrane is fragile - do not touch, do not scratch, do not let dry)) are important for accurate DO measurement.

Q5: What is the typical lead-time for order delivery?

A: Standard models require 7-30 working days. In-stock units can ship within 3-7 working days. Custom configurations or large built-to-order systems may require additional time, and we confirm the exact schedule before order confirmation.

Q6: Is regular calibration required? What is the recommended calibration cycle?

A: Calibration recommended: single-point air calibration before each use or at start of each field day (DO sensors drift, especially electrochemical; field conditions vary); full two-point calibration (air + zero) every 1-3 months or for high-accuracy/low-DO work. If probe is cleaned, membrane replaced, sensor changed, meter dropped, or readings seem off, recalibrate immediately. Routine verification: check in air-saturated water or humid air before each sampling session. For ISO 17025/commercial labs, follow applicable schedules and maintain records (calibration certificates, altitude/barometric pressure, as-found/as-left data, sensor ID). For wastewater NPDES compliance, calibrate per method (EPA 360.1) before each use and after each 8 hours of continuous use. DO measurement is highly sensitive to temperature and pressure - always enter correct altitude/barometric pressure for air calibration, and use ATC. Optical sensors are more stable (less frequent calibration) but still verify before use.

Q7: Are supporting consumables universal?

A: DO sensor/probe (replacement - specific to meter brand/model (Hach, YSI, Hanna, etc.; electrochemical and optical are not interchangeable; use OEM or certified compatible), membrane/electrolyte kits (electrochemical only - brand-specific), calibration solutions (zero solution (sodium sulfite) - can be lab-prepared or purchased; DO standards are not typically used (air is standard)), batteries (standard AA/9V - universal), BOD bottles (if BOD probe - standard lab glassware), and cleaning supplies are available from water quality/lab supply companies, though sensors and membrane kits are brand-specific (use OEM or certified compatible to maintain accuracy and warranty). Long-term consumable cost includes sensor replacement (periodic, $100-$500+) and membrane/electrolyte (electrochemical, regular).

Q8: Can I customize parameters or supporting accessories?

A: Customization includes sensor type (electrochemical (galvanic/polarographic Clark electrode - cheaper, needs membrane/electrolyte maintenance, consumes oxygen (needs stirring), good for general use) or optical (luminescent/fluorescence quenching - no electrolyte, no oxygen consumption (no stirring), low maintenance, more stable, better for field/BOD, but more expensive; recommended for most field use)), parameters (DO only, or multi-parameter (DO + pH + temperature + conductivity + salinity + ORP + turbidity + BOD)), form factor (portable/handheld (field, IP67, battery, rugged) or benchtop (lab, higher accuracy, more parameters)), cable length (1 m for surface, 3-30 m for deep water profiling, BOD probe for lab bottles), data/connectivity (basic (display only) or advanced (data logging (1000+ points), USB/Bluetooth/WiFi export, GPS, smartphone app, cloud, alarms for low DO, BOD mode)), accessories (extra sensor/probe, calibration kit (zero solution, calibration chamber), membrane/electrolyte kits (electrochemical), BOD bottles, spare batteries, carrying case (field), probe guard, calibration certificate, certifications (CE, FCC, ISO 9001, IP67), language and accessories. Additional sensors, cables, and accessories can be ordered separately.

Q9: Does the purchase include on-site installation and commissioning service?

A: Standard delivery includes portable DO analyzer, probe/sensor, calibration supplies (initial), batteries, carrying case, and instruction manual. On-site installation is not required for portable meters (charge, calibrate, use). On-site training is not included for standard orders but can be arranged at additional cost (for environmental/wastewater/aquaculture teams on calibration, sensor maintenance, field sampling technique, and data interpretation). Remote guidance provided. For multi-parameter continuous monitoring systems: installation and setup recommended. Always calibrate before field use.

Q10: What types of samples are compatible with this equipment?

A: The portable dissolved oxygen analyzer measures DO in various aqueous samples including natural water (rivers, lakes, streams, ponds, reservoirs, groundwater, estuaries, coastal seawater - field measurement), wastewater (influent, effluent, activated sludge, aeration basins, trickling filters - may be turbid/high particulate (probe needs cleaning)), drinking water (raw water, treated water, distribution system), aquaculture water (fish ponds, shrimp ponds, hatchery tanks, RAS, aquaponics - high organic, high fouling), beverage (beer, wort, wine, juice (low DO measurement may need special probe/technique; sample must not be agitated (agitation increases DO)), process water (industrial, cooling, boiler feed), and hydroponic/nutrient solutions. NOT compatible with: Samples with high oil/grease (coats membrane/cap, causes drift - clean thoroughly; may damage optical cap), highly corrosive samples (strong acids/bases beyond probe range - verify chemical compatibility of membrane/cap materials), samples with high sulfide (H2S - can poison electrochemical sensors (silver anode sulfidation); use sulfide-resistant probe or optical), samples containing solvents/organics that attack membrane materials (verify compatibility), and non-aqueous liquids (DO meters are for aqueous; oils/solvents need different methods). For very low DO (<0.1 mg/L, e.g., boiler water, anoxic wastewater): use high-sensitivity probe, zero calibration, and specialized technique (stagnant measurement for electrochemical is problematic). For BOD (biochemical oxygen demand): use BOD probe and standard method (5-day incubation, EPA 405.1/ISO 5815). IMPORTANT: Portable dissolved oxygen analyzer fundamentals: (1) What it measures: Dissolved oxygen (DO) = molecular oxygen (O2) dissolved in water. Units: mg/L (ppm) or % saturation. Saturation = amount of O2 water can hold at given temp/pressure (100% = fully saturated). Water at 20 degrees C, 1 atm: ~9.08 mg/L saturation. Colder water holds more O2 (0 degrees C: 14.6 mg/L; 30 degrees C: 7.5 mg/L). Higher altitude = lower saturation (less atmospheric pressure). Salinity reduces DO solubility (seawater holds ~20% less than freshwater at same temp). (2) Why DO matters: - Aquatic life: Fish need >5 mg/L (salmonids >6); below 2-3 mg/L = stress/death. - Wastewater: Aeration basins need 2 mg/L for activated sludge bacteria; effluent DO limits (NPDES permits often require >5 mg/L). - Drinking water: DO affects taste (flat taste if low), corrosion (high DO can corrode iron/steel pipes), treatment (aeration removes iron/manganese, CO2, H2S). - Beverage: Beer/wine need LOW DO (<0.1 mg/L in packaged beer) for shelf life (oxidation causes staling, off-flavors). - Corrosion: High DO accelerates corrosion in boilers, pipelines (deaeration used). (3) Sensor types: - Electrochemical (Clark electrode): Membrane (PTFE) allows O2 diffusion to cathode (gold) where it is reduced; current proportional to DO. Galvanic (self-generating, no external voltage) or polarographic (needs applied voltage, warm-up). Consumes oxygen at membrane (needs stirring/flow - stagnant = artificially low reading). Needs membrane + electrolyte (KCl) replacement. Affected by H2S (poisons silver anode). - Optical (luminescent): Blue light excites lumiphore on cap; red light emission is quenched by O2 (Stern-Volmer relationship). Does NOT consume O2 (no stirring needed), no electrolyte, low maintenance, not affected by H2S, more stable. Slightly more expensive. Recommended for field/BOD. (4) Calibration: - Air calibration (single-point): Probe in water-saturated air (100% humidity) = 100% saturation. Enter temperature and altitude/barometric pressure to calculate mg/L. Most common for field. - Zero calibration (two-point): Sodium sulfite (Na2SO3) solution scavenges O2 -> 0 mg/L. Improves accuracy at low DO. - Winkler method (iodometric, ISO 5813, ASTM D888 B): Reference method - chemical titration. Used for high accuracy and to calibrate/check meters. (5) Field measurement best practices: - Measure ON-SITE (DO changes during transport). - Calibrate before each use/day. - Rinse probe with sample before measurement. - Remove air bubbles from membrane/cap. - Electrochemical: stir gently or move probe (oxygen consumption). Optical: no stirring needed. - Shade probe from direct sunlight (algae photosynthesis produces O2, bright light can affect optical). - Report DO with temperature (and altitude/salinity if relevant). - For depth profiles: lower probe slowly, allow equilibration at each depth. (6) Common errors: - Not calibrating (biggest error - DO sensors drift). - Transporting sample (DO changes - measure on-site). - No stirring (electrochemical - low readings). - Air bubbles on membrane (high readings). - Wrong altitude/barometric pressure (air calibration error). - Probe fouling (biofilm, sediment - low/unstable readings; clean after each use). - Electrochemical membrane dry (permanent damage - store wet). - Direct sunlight (photosynthesis, optical interference). - Ignoring temperature (DO solubility is temp-dependent; always ATC). - H2S poisoning (electrochemical in wastewater with sulfide - use optical or sulfide-resistant). - Agitating sample (raises DO - especially for beverage/low-DO, measure gently). (7) DO ranges: - Saturated (air-equilibrated): 8-15 mg/L (depends on temp). - Good for fish: >5 mg/L. - Stress: 2-5 mg/L. - Lethal: <2 mg/L (warm water fish), <5 (salmonids). - Wastewater aeration: 1-3 mg/L (target 2). - Anoxic: <0.5 mg/L (denitrification). - Anaerobic: 0 mg/L (septic, sludge digestion). - Packaged beer: <0.1 mg/L (desired for shelf life).