Top 10 Best pH Meters for Water Testing in 2021

Written By Dr. Fatima Saifee

March 10, 2021

Lab Equipments

Introduction

pH meter is an electric device, with a sensitive electrode sensor to measure hydrogen-ion activity in solution. It is a testing instrument or a tool to detect pH between the values of 0 and 14.

  • The pH is a logarithm of base 10 which is a negative value that corresponds to Hions in the solutions [H+].
  • pH = – log 10 [H+].
  •  Slight changes in pH make the solution acidic or alkaline. pH range actually indicates the concentration of H+ and OHpresent in the solutions. Normally the pH range from 0-14.
  • Water molecule ionizes into H+ ions and OH ions. A slight change in H+ ions and OH results in a change in pH. The water is in neutral condition if the H+ ions and OH are in equilibrium at pH 7.
  • Below 7.0 the solutions become acidic in nature and above 7.0 the solutions become alkaline in nature.
  • To get an accurate reading of pH always uses a pH meter.

Why do we need a pH meter?

  • pH plays an important role in the chemistry of solutions.
  • The presence of nutrients, chemicals, or other additives in water it is important to measure the pH of the water and other liquids
  • The pH of water has a great impact on human health. This pH meter is useful for household and laboratory use to improve the quality of life.

Application of pH Meter

Common parameters measured in a wide variety of domestic and industrial applications.

  • Water purification systems like drinking water, pool, aquarium, Spa, or hydroponics.
  • Wastewater treatment like boilers & cooling towers.
  • Agriculture research and crop production improvement.
  • Chemical and electronics production.
  • Environmental monitoring.
  • Chemical and life sciences research.
  • Biochemical and pharmaceutical research.
  • Food processing and Cosmetic Evaluation.

Principle

  • The pH value is measure through an EMF cell which is inbuilt of two electrodes in it, one electrode determines the pH of the sample and the other one works as a reference electrode.
  • The glass electrode is used to measure the pH of the sample and able to detect the movement of hydrogen ions concentration in the solution. The reference electrode is made of calomel or mercury,
  • The pH value can be obtained with these two electrodes in the solution. In a variety of electrodes, Hydrogen gas-based electrode is recommended for electrometric determination of pH reading.
  • The principle of working of glass electrode is explained by the fact that a change of slight pH even 1 unit which changes in volts by 59. 1 mV at 25°C.
  • This cover separates the two liquids between the reference electrode and the indicator electrode and generates potential on both sides of the covering which is directly proportional to the distinction in pH of the two liquids.

Apparatus and Reagents used

  • pH meter
  • Beaker or flask required to pour the water sample
  • Wash bottle for distilled water
  • Water sample bottle.
  • pH Buffer 7.0
  • pH Buffer 4.0

Calibration

  • Always calibrate the pH meter to analyze the sample for the better results
  • Turn on the pH meter
  • First, clean the electrode with distilled water thoroughly.
  • Now put the cleaned electrode into the pH buffer solution 4.0 in a beaker. Press the “CAL” (calibration) button for 5 seconds and release and wait until the pH meter shows the value 4.0.
  • Rinse the electrode with distilled water and put the solution into the pH buffer 7.0 and wait till the value shows correctly as per the buffer pH.
  • Take care at the time of calibration to get an accurate reading of the pH meter. Sometimes values may not be correct if the buffer is contaminated.
  • The pH meter measures, the nature of the sample is acidic, or basic by showing the pH.
  • To analyze the number of samples note the reading of pH and temperature.
  • In the turbid sample, extra care should be taken to avoid the false reading which may interfere with the actual reading.

Precautions

  • A properly manufactured and maintained pH electrode will retain its measuring integrity for a long time. As a result of many factors such as age, poor maintenance, or improper handling, any electrode in time will lose its integrity.
  • The most common cause for pH measurement inaccuracies is an unclean or improperly cleaned electrode. Do not drop the entire meter in the water or dip beyond the maximum immersion line.
  • A dirty electrode or wrong calibration approach can contribute to buffer solution contamination.

1. Apera Instruments AI311 PH60 Premium Waterproof pH Pocket Tester, Replaceable Probe

FEATURES

  • High-quality replaceable glass bulb pH probe
  • EASY 1-3 points auto. calibration
  • Auto Temp. Compensation (ATC) ensures accuracy in various temperatures (32-122˚F)
  • LARGE CLEAR LCD
  • dual display of temp./pH,
  • COMPLETE KIT with READY-TO-USE calibration solutions, calibration bottles, storage solutions, AAA batteries, and a lanyard all in a rugged portable case.

USES

Pools & spas, hydroponics, environmental monitoring, cooling towers, beverage, water treatment, etc.

LIMITATIONS

  • The instrument will NOT give accurate or stable readings for distilled or deionized water’s pH testing.
  • Do NOT store the probe in distilled water or deionized water because they will cause damage to the pH probe. Only use distilled or deionized water for rinsing the pH probe.

2. Apera Instruments AI3711 PH60-Z Bluetooth Smart pH Tester Powered by ZenTest Mobile App with Cloud-Based Datalogger

FEATURES

  • Apera PC60-Z Smart Multi-parameter Pocket Tester design for seamless water test experience.
  • Comprehensive Information Display for pH, conductivity (EC), TDS (ppm), salinity (ppt), resistivity, and ORP.
  • Cloud-based data logger.
  • Two-way controlling.
  • Double-junction replaceable pH probe.
  • Calibration reminder setup.
  • Alarm function to notify you of any values exceeding a preset range.
  • Upgraded double-junction blue pH probe – More durable and easier to use.
  • Mobile App is available for Apple and Google Play Store.
  • Easy to connect the smartphone with Bluetooth.
  • Ability to add GPS location, notes, and even a photo to your saved measuring data.
  • Portable carrying case with calibration solutions, calibration bottles, storage solutions, 4*AAA batteries, and a lanyard, and a quick-start manual.

USES

  • This Hybrid design product can be used as a classic tester even without connecting to a smartphone.
  • Double-junction replaceable pH probe, more durable and easier to use,
  • It is ideal to use for measuring complex or dirty solutions and reduces the chance of a clogged junction, removes any air bubble forming inside the sensor for consistent pH measurement.

    3. Dr.meter Upgraded PH838 0.01 Resolution High Accuracy Backlit Two-Color LCD Display pH Meter with ATC, 0-14pH Measurement Range with Data Hold Function

    FEATURES

    • Professional Accuracy gives quick and right data with the highly sensitive electrode.
    • 3 Point Automatic Calibration makes the job faster and easier
    • Automatic Temperature Compensation range between 0-70 degrees, in any environment.
    • Clear Digital Display with Alerts on backlit LCD screen even in low visibility situations.
    • White digital display will change to red alert when pH is lower than 3.5 or higher than 12.5
    • User-friendly- easy to activate the 15-minute auto-off functionality to save battery
    • Provided with storage case to keep it safe and protected.

    USES

    • It is best to use for drinking water to swimming pools, aquariums, spas, hydroponics operations, and the food, wine, and beverage industries

    4. Bluelab PENPH pH Pen Fully Waterproof Pocket Tester, Easy Calibration (Twо Расk)

    FEATURES

    • Professional Accuracy gives quick and right data with the highly sensitive electrode.
    • 3 Point Automatic Calibration makes the job faster and easier
    • Automatic Temperature Compensation range between 0-70 degrees, in any environment.
    • Clear Digital Display with Alerts on backlit LCD screen even in low visibility situations.
    • White digital display will change to red alert when pH is lower than 3.5 or higher than 12.5
    • User-friendly- easy to activate the 15-minute auto-off functionality to save battery
    • Provided with storage case to keep it safe and protected.

    USES

    • It is best to use for drinking water to swimming pools, aquariums, spas, hydroponics operations, and the food, wine, and beverage industries

    5. Hanna Instruments HI98103 Checker pH Tester with pH Electrode and Batteries, 0.00 to 14.00 pH, +/-0.2 pH Accuracy, 0.01 pH Resolution

    FEATURES

    • Compact pH tester with a narrow probe for use in small samples or test tubes
    • Manual two-point calibration through trimmers for custom calibration
    • Single-line LCD display screen for ease of viewing
    • Replaceable electrode with screw connector to extend meter life
    • Low power demand for extended battery life

    USES

    • Ideal for small amount of water samples in test tubes

    6. HMD PH-200 Digital Professional Waterproof 0-14 PH & Temperature Meter

    FEATURES

    • HM Digital’s PH-200 is a digital waterproof pH meter.
    • Made of plastic.
    • Imported quality.
    • Measures pH range 0-14 pH and Temperature range 0-80 °C, 32-176 °F.
    • Auto-ranging three point calibration
    • Includes storage solution in a sponge embedded in a clear cap.
    • Auto-off function, data-hold function, and low-battery indicator.
    • Amazing features for laboratory professionals.

    USES

    Ideal for all pH testing in water purification applications, wastewater regulation, aquaculture, hydroponics, colloidal silver, labs & scientific testing, pools & spas, ecology testing, boilers & cooling towers, water treatment, wine, coffee, agriculture, and much more.

     

    7. Lab Junction pH Meter,Auto pH Meter (Table Top) 2 Point Calibration Facility with Touch Key’s,Model:LJ-111 as per Quality Standards for Laboratory

    FEATURES

    • Lab Junction’s Auto Deluxe pH Meter is in Compact size
    • Ideal instrument for the determination of pH value of an aqueous solution.
    • These are unique instruments that combine convenience with accuracy and precision in analysis.
    • The temperature Compensation facility both automatic and manual is available.
    • The measurement range is from 0 to 14 pH with a resolution of 0.01 pH.
    • Accurate measures pH and mV and Temperature reading
    • Highly Stable and Accurate 3 Digit Display
    • Touch Keys Auto Polarity and Low battery indicator.
    • Operation Manual available
    • For Laboratory 2 Point Calibration Facility pH Meter, Auto pH Meter

    USES

    These are extremely useful instruments for agriculture and soil analysis laboratories, swimming pools, fertilizer plants, chemical industries, pharmaceuticals industries, petroleum refineries, textiles plants, etc.

    PRECAUTIONS

    • Always rinse the pH electrode with distilled water before next use. If the electrode has been exposed to a solvent immiscible with water, clean it with a solvent miscible with distilled water.
    • Never touch or rub the glass bulb in order to last pH electrode life.
    • Make sure the electrode is clean.

     

    8. Lab Junction pH Meter, Auto Delux pH Meter,3 Point Calibration, Model:LJ-101

    FEATURES

    • Lab Junction’s Auto Deluxe pH Meter is in Compact size
    • Ideal instrument for the determination of pH value of an aqueous solution.
    • These are unique instruments that combine convenience with accuracy and precision in analysis.
    • The temperature Compensation facility both automatic and manual is available.
    • The measurement range is from 0 to 14 pH with a resolution of 0.01 pH.
    • Accurate measures pH and mV and Temperature reading
    • Highly Stable and Accurate 3 Digit Display
    • Touch Keys Auto Polarity and Low battery indicator.
    • Operation Manual available

    USES

    These are extremely useful instruments for agriculture and soil analysis laboratories, swimming pools, fertilizer plants, chemical industries, pharmaceuticals industries, petroleum refineries, textiles plants, etc.

    PRECAUTIONS

    • Always rinse the pH electrode with distilled water before next use. If the electrode has been exposed to a solvent immiscible with water, clean it with a solvent miscible with distilled water.
    • Never touch or rub the glass bulb in order to last pH electrode life.
    • Make sure the electrode is clean.

     

    9. Hanna HI98107 New pHep, 0.1 pH, with ATC, Waterproof

    FEATURES

    • Ideal to use in the hand or pocket, slim, ergonomic design with rounded edges and a case.
    • Large Multi-Level LCD
    • Easy to read both the pH and temperature simultaneously with Two-Button Operation Two-Button Operation
    • pH range 0.0 to 14.0 pH with accuracy ±0.1
    • Temperature Range: 0.0 to 50.0 degree Celsius or 32.0 to 122.0 degree Fahrenheit with Accuracy: ±0.5 degree Celsius or ±1 degree Fahrenheit
    • Automatic calibration for pH and Temperature compensation
    • Battery Type or Life: approximately 800 hours of use
    • Auto-off after 8 minutes, 60 minutes, disabled
    • Stability Indicator: A clock tag stability indicator will disappear to alert the user when the reading is stable
    • Automatic shut-off, with Options, are 8 min, 60 min, or disabled to conserve battery life
    • Low Battery Indicator

    USES

    Ideal for drinking water, pool, aquarium, laboratory, spa or hydroponics, school lab, food, and drink.

     

    10. Konvio Neer pH Test Meter ± 0.1pH High Accuracy with 0.00-14.00ph (Digital pH Meter)

    FEATURES

    • Accurate PH meter
    • Automatic calibration
    • Wide range of uses
    • Automatic Temperature Compensation
    • Pocket size
    • Measuring range of 0-14 PH,
    • Easy to Use
    • Easy to Calibrate
    • High Quality and Durable
    • LCD display, reliable and quick reading.

    USES

    Best for Drinking-Water, Hydroponics, Aquariums, Swimming Pools

     

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    2 Comments

    1. Keita Djibril

      Wow!!! Perfect resume on water pH determination. The price of the products is also affordable since there are the best quality.

      Reply

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