pH meters, conductivity meters, dissolved oxygen, ORP, and turbidity instruments
115 products

Now you can test pH on the spot easily and accurately with the ExStik PH110 Waterproof pH Meter. The durable ExStik meter features a flat surface refillable electrode for measuring pH in liquids, semi-solids, and solids – no more electrode breakage or clogged junctions. Since you can refill the ExStik quickly, you won't need to worry about the shelf life of its electrode. the ExStik meter is an invaluable tool for measuring the pH in shampoo, body wash, facial cleansers, lotions, creams, and more. Use it to monitor pools and spas, or to measure acidity and alkalinity in soil, skin, and carpeting. It's valuable in hydroponic gardening or farming. Get important readings in cement, agriculture, fish farming, wastewater, antifreeze recycling, food preparation, cleaning supplies, and manufacturing of paper, pulp, and paint. Comes complete with the refillable pH electrode, a 1.5mL bottle KCI, two reference junctions, two removal tools, a protective cap, a sample cup, four 3V CR-2032 batteries, and a 48 inch (1.2m) neck strap.

pH Meter, Palm pH with Cabled Electrode

The Extech PH300 pH/Temperature Kit measures pH, mV, and temperature at your workbench or in the field. It has automatic, one button calibration of 4, 7 and 10 pH with a choice of three point calibration, for better accuracy and automatic temperature compensation. Memory stores up to 200 readings with series number, measured value, and temperature. The meter has a large, blue, backlit LCD display screen with an auto power off function plus disable function that saves battery life. The IP57 waterproof housing protects it from moisture and the elements. Comes with a pH/mV/temp electrode, a protective rubber holster, the pH calibration solutions (4, 7, and 10 pH), two AA batteries, hard carrying case, and user manual.

Rugged waterproof (IP57) housing with Flat Surface Electrode for measuring pH in liquids, semi-solids, and solids. Does not break or get junctions clogged like the traditional glass bulb electrodes. Easy to replace sensor is perfect for field or lab use.

ORP meter with rugged flat surface ORP electrode and high resolution of 1mV

The Extech RF20 measures the concentration of dissolved salt in fluids. It has a compact size and is easy to operate. Automatic Temperature Compensation (ATC) from 10°C to 30°C. Comes with case, calibration screwdriver, plastic pipette calibration solution, and user guide.

Records data on an SD card in Excel format

The Extech SDL150 records data on an SD card in Excel format. It has a dual backlit display of oxygen concentration and temperature. It measures dissolved oxygen from 0 mg/L to 20.0 mg/L and 0% to 100.0% oxygen, plus temperature from 0°C to 50°C (32 to 122°F). Includes automatic temperature compensation from 0°C to 50°C via temperature probe sensor built into polarographic type oxygen probe. Offset adjustment used for zero function to make relative measurements. The SDL150 stores 99 readings manually and 20M readings via a 2G SD card. User programmable sampling rate. It has a built-in PC interface, min/max and data hold functions, and an auto power off. Complete with 6 x AA batteries, SD card, probe, two spare replacement membranes, electrolyte, and hard carrying case.

TB400 is a Portable Turbidity Meter that tests water, food, beverages and other aqueous solutions. Meter comes complete with all the accessories to conveniently test the turbidity of municipal water, food and beverage water, and other aqueous solutions where fluid clarity is important. Portable design allows you to take measurement on-site instead of bringing solution back to the lab. Measures up to 1000 NTU (Nephelometric Turbidity Unit) with 0.01 NTU resolution. Complete with 0 NTU standard solution test bottle, 100 NTU standard solution test bottle, cleaning solution (distilled water), (2) test bottles and covers, cleaning cloth, six AAA batteries, and hard carrying case.

Multi-parameter four-wire liquid analysis transmitter — modular electronics support a wide range of measurement combinations including differential conductivity, dual oxygen, pH/ORP + chlorine, and many more. Drives most industrial, commercial, and municipal liquid-analysis applications from a single transmitter platform. Backlit graphical display with multi-language UI. The mid-tier Rosemount Analytical transmitter — broader sensor support than the 56, less channel count than the 1057.

Triple-channel liquid analysis transmitter — three independent pH/ORP and/or conductivity inputs in one transmitter housing. Reduces installed cost and panel space when a process requires multiple measurements at a single location (boiler-feedwater plants, electrochemistry plants, multi-tank monitoring). Modular sensor-input cards. Same UI family as the 1056. Best when consolidating three sensors that would otherwise need separate single-channel transmitters.

Single-channel liquid analysis transmitter — drives one sensor (pH/ORP, contacting or toroidal conductivity, dissolved oxygen, chlorine, ozone, turbidity). Same modular electronics platform as the 1056 / 1057. The single-channel choice for tight panel-space installations where a 1056 dual is over-spec, but a loop-powered 5081 isn't suitable (need full 4-wire operation, broader I/O, larger display).

Toroidal conductivity sensor with robust, fouling-resistant geometry for harsh, corrosive, and fibrous liquid applications — pulp & paper, sugar processing, food/beverage CIP/SIP. Same 0-2 S/cm range as the 228 but with body materials and dimensions optimized for process applications with extreme fouling potential. The 226 outlasts the 228 in fibrous and abrasive media; the 228 wins in tighter pipes (smaller form factor).

Toroidal (inductive) conductivity sensor that reliably measures conductivity in highly conductive electrolyte solutions up to 2 S/cm (2,000,000 µS/cm). The toroidal design — no metal electrodes touching the process — makes it the right choice for dirty and corrosive applications where contacting sensors (like the 400) foul or corrode. Best for chlor-alkali, salt brines, acid/caustic transfer, and waste streams. Mounting variants for in-pipe insertion, flow-through, and submersion.

Premium pH/ORP sensor for high-temperature, high-pressure, fouling/coating applications — robust design significantly prolongs sensor life in complex chemistries (chlor-alkali, semiconductor, hydrocarbon). Resists fouling, coating, and reference-junction poisoning that defeat standard pH sensors. VP variable-pin connector option (3300HTVP) for VP-cable compatibility with the 1056 / 1057 / 5081 transmitters. The Rosemount Analytical workhorse for severe-service pH measurement.

Mid-tier general-purpose pH/ORP sensor with double-junction reference — protects the reference element from poisoning ions (ammonia, chlorine, cyanides, sulfides) that kill single-junction reference sensors. Wide range of installation styles: insertion, submersion, retractable. Cost-effective workhorse for water/wastewater, general process, and any application where the 3300HT premium would be over-spec. VP version (3900VP) for variable-pin connector compatibility.

pH/ORP sensor designed for harsh, dirty, abrasive applications — lime slurry waste treatment, paper-machine headbox, pigment/dye production, and any process with large quantities of suspended solids. Wear-resistant body and reference geometry that survives where standard 3900 sensors fail in months. Insertion mounting standard. VP connector option (396PVP). The Rosemount choice for the dirtiest pH measurement jobs.

Contacting (electrode) conductivity sensor for clean, low-conductivity liquids — high-purity water, ultrapure rinse water, clean cooling water, condensate. Factory-measured cell constant (0.01, 0.1, or 1.0/cm) ensures out-of-the-box accuracy with no initial calibration. Wetted parts: titanium electrodes, 316 SST body, PEEK insulator, EPDM O-rings. Direct screw-in 3/4 in MNPT process insertion. Range: <20,000 µS/cm. The right choice when sample is clean — toroidal sensors (228 / 226) are over-spec for ultrapure water.

Membrane-covered amperometric dissolved oxygen sensor — continuously measures DO between 0-20 ppm. The lower-cost alternative to the optical RDO when daily calibration burden is acceptable and maintenance staff is regularly on-site. Best for municipal and industrial wastewater aeration basins, where the 499ADO has decades of installed-base reliability. Membrane and electrolyte are field-replaceable; rebuild kits available for multi-year sensor life.

Single-channel loop-powered (4-20 mA HART) liquid analysis transmitter in an explosion-proof housing. Accepts pH/ORP, contacting / toroidal conductivity, and amperometric (DO / chlorine / ozone) sensors. Rugged weatherproof corrosion-resistant enclosure for hazardous-area installations (Class I Div 1, Zone 1) — the Rosemount Analytical choice when other transmitters need separate explosion-proof enclosures and conduit fittings. Loop-powered means no separate power supply or 4-wire conduit run.

Dual-channel liquid analysis transmitter — accepts two independent sensor inputs (any combination of pH/ORP, contacting / toroidal conductivity, resistivity, dissolved oxygen, free chlorine, total chlorine, ozone, turbidity). Large color graphical display with intuitive menu structure. Used in water/wastewater plants, chemical process plants, and any installation where two analytical measurements share one transmitter location for cost efficiency.

Complete free-chlorine measurement system for fresh water — bundles a 499ACL free chlorine sensor, 56 or 1056 transmitter, optional pH sensor (for pH-corrected reading up to pH 9.5), and a constant-head flow controller. Continuous pH correction eliminates the expensive reagents and troublesome sample-conditioning systems that plague competitor chlorine analyzers. Best for drinking-water distribution, swimming-pool monitoring, and wastewater disinfection feedback control. The Rosemount Analytical drop-in solution that includes everything you need to start measuring chlorine.

Optical (luminescent-quenching) dissolved oxygen sensor — measures DO in wastewater aeration basins, ponds, and surface water without the membrane fouling, electrolyte depletion, or zero-drift issues of older membrane DO sensors. No daily zero calibration. Typical sensor life 1-2 years between cap replacements (vs 3-6 months for membrane). Best for municipal wastewater aeration optimization, fish farming, and any DO measurement where maintenance burden has historically been a problem. The Rosemount choice when 499ADO membrane sensor's lower cost is outweighed by maintenance time.

Pre-engineered, pre-tested water-quality monitoring panel — combines user-specified Rosemount Analytical sensors and transmitters in one drop-in cabinet for fresh-water monitoring. Customizable measurement set: pH, ORP, conductivity, temperature, free chlorine, monochloramine, dissolved oxygen, turbidity, and particle index. Replaces the cost and risk of field-assembled panels; ships fully wired, leak-checked, and pre-calibrated. Best for drinking-water utilities and municipal water plants needing standard EPA/ISO regulatory monitoring without integration burden.