pH Meters/Colorimeters

The proper and accurate measurement of pH is one of the most critical factors in any laboratory procedure. 

At Next Day Science, we offer pH meters that meet even the most demanding pH measurement requirements. 

In addition to checking general acidity and alkalinity, our specialized meters measure the pH of silica, chlorine, phosphate, phosphorus, bromine, calcium, chromium, and ammonia, From bench top to portable to pocket pH meters, you are sure to find the right meter for your laboratory needs.

For more information, read the descriptions of individual meters.

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pH Meters/Colorimeters Questions & Answers

What can a pH meter be used for?

Multiple advancements in instrumentation and detection have expanded the range of applications in which pH measurements can be conducted. The devices are much smaller now, enabling direct measurement of pH inside of living cells. In addition to measuring the pH of liquids, specially designed electrodes are available to measure the pH of semi-solid substances, such as foods. These have tips suitable for piercing semi-solids and are resistant to clogging.

pH meters are used in healthcare and clinical applications, such as blood chemistry, in manufacturing, for soil measurements in agriculture, water quality in swimming pools, aquariums, brewing wine or beer, environmental remediation, and municipal water supplies.

Do pH meters have to be calibrated?

Yes, before taking a pH measurement you must calibrate the pH meter.

Calibration is especially important if the meter has been stored or used to test a pH range that is vastly different from the one you need to test.

How do I calibrate my pH meter?

Yes, before taking a pH measurement you must calibrate the pH meter.

When you calibrate a meter you are checking the pH meter against a known buffer solution to ensure that it reads pH correctly.

To calibrate a pH meter, you must choose a minimum of two buffers for a two point calibration (except pH meters that have only a 1-point calibration feature), one always being pH 7, and a second point which covers the expected pH of your sample.

What tips can you give for pH buffer use?

Solutions of known pH value allow the user to calibrate the pH meter to make accurate measurements.

For the highest accuracy:

• Standardization should always be completed with fresh buffer solutions.

• Buffers used should support the range of pH for the samples being tested.

• Buffers should be at the same temperature as the samples because buffer values are dependent upon temperature.

How should I store my pH meter?

Unless otherwise specified by the manufacturer, the electrode should be stored in a manner that allows the bulb of the electrode to remain moist/hydrated.

Electrodes typically include a protective cap with a piece of sponge or absorbent material inside. Add a few drops of storage solution or 4.01 buffer solution to the cap and then place the cap back on the electrode. This will work for short or long term storage.

How should a pH electrode be cleaned?

A dirty glass membrane is usually indicated by beads of water forming on the bulb when it's rinsed with distilled water. The bulb can be cleaned as follows:

• For protein layers, soak in a freshly prepared solution of 1% pepsin in 0.1N HCl for 30 minutes.

• For inorganic deposits, wash with a 1M EDTA solution, 2M ammonia, or 2M acid.

• For grease and similar films, wash with acetone, methanol, etc.

How long will my electrodes last?

pH electrodes can be used for approximately a year, if the machine and bulb are stored properly and cleaned regularly.


What is a colorimeter used for?

Laboratory colorimeters, also referred to as digital colorimeters, are instruments used to measure the absorbance of wavelengths of light at a particular frequency (color) by a sample utilizing the Beer-Lambert’s law. Digital colorimeters are used widely across different work areas to include clinical diagnostics, pharmaceutical analysis, biochemistry, and environmental testing. In particular, a portable colorimeter can be used for on-site environmental analyses.

Colorimeters can be used to test water quality, by screening for chemicals such as fluoride, chlorine, cyanide, dissolved oxygen, iron, zinc, phosphorus, calcium, silica, bromine, ammonia, and more. They are also used to determine the concentrations of plant nutrients (such as phosphorus, nitrate and ammonia) in the soil or hemoglobin in the blood and to identify substandard and counterfeit drugs. In addition, they are used by the food industry and by manufacturers of paints and textiles

What are the benefits of a colorimeter vs chemical test kits?

The handheld colorimeter is easier to use and more accurate than chemical test kits. The chances of mis-reading results due to individual vision quality are reduced because the colorimeter is consistent and accurate every time. They are dedicated to a single parameter and they are small and convenient.

What size of battery does the colorimeter use?

The HannaChecker handheld colorimeters from Next Day Science use 1 AAA battery to operate and have an automatic power-off after 10 minutes of inactivity to help save the battery life.

Is the colorimeter difficult to use?

The process of using the colorimeter is quite simple. The small, but accurate, handheld devices can provide quick, consistent results in just four simple steps.

  1. Step One - Add a sample to the included cuvette(s)
  2. Step Two - Insert sample into the Checker and zero it out
  3. Step Three - Remove sample and add reagent
  4. Step Four – Reinsert sample and click the button to measure your results or - Press and hold the button for 3 seconds for a time reaction reading

How can I be sure I’m using the correct colorimeter?

Each Checker® HC Handheld Colorimeter is color coded as well as clearly labeled by the test button to prevent using the wrong colorimeter.