Portable pH and ORP Meters — HORIBA LAQUA PH210-K & PH220-K

pH is the measure of hydrogen ion concentration in a solution — the scale runs from 0 (strongly acidic) to 14 (strongly alkaline), with 7 representing neutral. It is one of the most frequently measured parameters in water quality monitoring, process control, environmental assessment, and laboratory analysis. ORP (Oxidation-Reduction Potential), measured in millivolts, indicates the oxidising or reducing capacity of a water sample and is used to verify disinfection, assess redox conditions in biological treatment, and characterise groundwater chemistry.

HORIBA Australia supplies two portable pH/ORP meters from HORIBA‘s LAQUA range. The PH210-K and PH220-K measure pH, ORP, and temperature from the same electrode. Both include the 9652-10D gel-filled pH/temperature electrode, pH 4, 7, and 10 buffer solutions, and a carrying case as standard. The PH220-K adds GLP data logging with date/time stamp and USB data transfer to PC.

Both meters are IP67 rated and carry a 3-year warranty (on meter only. 6 months warranty on electrodes). Contact us if you need help selecting the right model.

PH210-K vs PH220-K — Which Model Do You Need?

What Does a Portable pH Meter Measure?

Both the PH210-K and PH220-K measure three parameters from the same 9652-10D gel-filled electrode:

pH
pH is measured on a continuous scale from -2.00 to 16.00 pH with 0.01 resolution and ±0.01 pH accuracy. The meter supports automatic calibration at up to 5 points using NIST/USA standard buffers (pH 4.00, 7.00, 10.01) or up to 6 points using DIN buffers. Buffer recognition is automatic — the meter identifies the standard solution on immersion without manual entry. Offset and average slope are displayed after each calibration to indicate electrode condition. A programmable calibration alarm (up to 90 days) alerts the operator when recalibration is due.

ORP (Oxidation-Reduction Potential)
ORP is measured in millivolts via a separate ORP electrode (9300-10D, sold separately). Range: ±2000 mV, accuracy ±0.3 mV. An ORP calibration function is included. When the ORP electrode is connected in place of the pH electrode, the meter switches to millivolt measurement mode automatically.

Temperature
The integrated temperature sensor in the 9652-10D electrode measures -30.0 to 130.0°C with ±0.5°C accuracy. All pH measurements include automatic temperature compensation (ATC) — pH readings are automatically corrected for temperature-dependent electrode response. Manual temperature entry is also supported. Temperature can be displayed in °C or °F.

Key Features

IP67 Waterproof and Shock-Resistant Housing
Both meters are rated IP67 — fully dustproof and protected against temporary immersion. The polycarbonate housing is shock and scratch-resistant with a non-slip grip. The built-in electrode holder accommodates two electrodes simultaneously — useful when carrying both a pH electrode and an ORP electrode in the field.

Up to 5 or 6-Point Automatic pH Calibration
Automatic calibration with buffer recognition across up to 5 standard points (NIST/USA: pH 1.68, 4.00, 6.86, 9.18, 12.46) or up to 6 DIN buffer points is a significant advantage over cheaper meters that offer only 1 or 2-point calibration. Multi-point calibration accounts for non-linear electrode response across the measurement range, improving accuracy at pH values distant from the primary calibration point.

Auto Stable, Auto Hold, and Real-Time Measurement Modes
Auto Stable mode holds the display until the reading stabilises — eliminating premature recording of drifting values in variable field conditions. Auto Hold freezes the reading for manual recording. Real-time mode shows continuous live measurement for process monitoring.

Programmable Calibration Alarm
The calibration alarm can be set for any interval up to 90 days. On expiry, the meter alerts the operator that calibration is due — supporting quality management systems and GLP compliance requirements.

Data Logging — PH220-K
The PH220-K stores up to 1,000 data sets with a real-time clock and date/time stamp, enabling full GLP-compliant data management. Data transfers to PC via USB cable and to printer via RS232. The PH210-K stores up to 500 data points but connects via phono jack for firmware upgrades only — not for data export. Choose the PH220-K where dated records, USB export, or printed output are required.

Applications for Portable pH and ORP Meters

Environmental Monitoring and Field Surveys
pH is a standard measurement in river, lake, groundwater, and estuary assessments. It is a key indicator of water quality condition, influences metal speciation and toxicity, and is required for characterising water body health under Australian and state environmental frameworks. The PH210-K is appropriate for routine field surveys where on-site data logging without PC export is sufficient; the PH220-K is preferred where traceable, date-stamped records are required for regulatory submission.

Drinking Water Treatment and Distribution
pH control is critical throughout the drinking water treatment process. Optimal coagulation typically occurs within a narrow pH range (6.5–7.5 depending on coagulant type); disinfection effectiveness with chlorine is highly pH-dependent (most effective below pH 7.5); and Australian Drinking Water Guidelines (ADWG) specify pH limits for treated water supplied to consumers. ORP measurement supplements pH for verifying chlorine disinfection residual. Portable meters allow treatment plant operators to test at any point in the system without relying solely on fixed online monitors.

Groundwater Assessment
pH and ORP are the two parameters most fundamental to characterising groundwater chemistry in contaminated site investigations. ORP in particular defines whether a groundwater system is oxidising or reducing — governing metal solubility, contaminant mobility, and natural attenuation processes. The PH220-K’s GLP logging with date/time stamp supports the traceable data records required in site remediation programmes.

Aquaculture and Hatcheries
pH directly affects fish physiology — most freshwater species are sensitive to pH outside the range of 6.5–8.5. Regular pH monitoring is standard practice in intensive aquaculture to detect bicarbonate depletion, algal activity, and acidification events before they affect stock health. For combined pH and dissolved oxygen measurement from a single instrument, see the LAQUA PD210-K.

Wastewater Treatment
pH is monitored across all stages of biological wastewater treatment — influent characterisation, aeration basin control, and effluent compliance. ORP is used to characterise oxidising and reducing conditions in aerobic, anoxic, and anaerobic zones. Both parameters are standard in the Australian Water Quality Guidelines for effluent discharge compliance.

Industrial Process Water and CIP
pH monitoring is standard practice in food and beverage manufacturing, pharmaceutical production, chemical processing, and clean-in-place (CIP) systems. The calibration alarm function and GLP data logging of the PH220-K support the quality management documentation requirements common in these industries.

Kit Contents and Accessories

Both the PH210-K and PH220-K are supplied as complete kits including:

• LAQUAact PH210 or PH220 meter
• 9652-10D plastic-body, gel-filled pH/temperature electrode
• pH buffer solutions: pH 4.00, 7.00, 10.01 (60ml each)
• 2 x AA batteries
• Carrying case
• Manual and quick guide

Note: ORP electrode (9300-10D) is sold separately for both models. The built-in electrode holder accommodates both the pH electrode and ORP electrode simultaneously.

Replacement pH electrodes, ORP electrodes, and buffer solutions are available separately. See our calibration solutions and buffer standards range.

For pH measurement alongside conductivity/TDS/salinity from a single instrument, see the LAQUA PC210-K or PC220-K. For pH alongside dissolved oxygen, see the LAQUA PD210-K or PD220-K. For comprehensive multi-parameter field monitoring including turbidity, depth, and GPS, see the HORIBA U-50 Series.

Also available:

• All portable water quality meters
• pH buffer solutions and calibration standards
• LAQUA PH210/PH220 instruction manuals and brochures
• Contact Australian Scientific for technical support or volume pricing