This is edge®.

A laboratory pH, conductivity, and dissolved oxygen meter that transforms your lab measuring experience.

Tablet Meters

Designed for dynamic environments.

edge’s flat profile and long-lasting battery make it easy to carry around your lab while its compact cradle saves valuable space. For smaller labs, mount edge on your wall for easy viewing.





inch thick


oz. weight


hours battery life


inch display


USB ports


mm connection


pH electrodes


pH CAL points


pH electrode diagnostics


logged data points


year meter warranty

Stands out in a busy lab.

A large, clear LCD displays your results from up to 15 feet away for easy recognition and monitoring while you’re preparing samples or running other tests.




Start anywhere. Expand later with an additional sensor.

edge® pH+



Our most popular edge tablet meter. Expandable to conductivity and dissolved oxygen.

edge® EC+



Start with conductivity and TDS (ppm), expand to pH and DO.

edge® DO+



You can also start with dissolved oxygen.


Customize your pH testing experience.

With a wide variety of digital pH electrodes to choose from, expanding edge to meet your needs is easy.






General Use












General Use




See all digital electrodes >

Easy to learn. Easy to use.

edge® brings professional results to business and educational laboratories worldwide.

"Spot on!"

The instrument sets up and calibrates in moments, is intuitive to use, the arm support is perfect, the DO probe is robust and accurate.

-Paul S.

Website Review

"Awesome product"

Very good looking instrument, with very easy to learn user interface. Also the 1 point calibration saves time and money.

-Max L.

Website Review

"Great pH Meter"

So far, this pH meter has been great! Super easy to use and very low profile. A lot of options with the digital probe that are really nice.

-Kate L.

Website Review


Choose a more focused model for dedicated measurements.

edge® pH



Single testing for pH & ORP. Compatible with other digital pH electrodes.

edge® EC



Single testing for conductivity & TDS (ppm).

edge® DO



Fast dissolved oxygen calibration. Polarographic membrane sensor.


Take care of your electrodes.


Trust that your pH probes are properly cared for with cleaning solutions ranging from dairy deposits to soil.

Shop pH cleaning solutions >


Our extensive line of calibration solutions are formulated for a variety of needs, from the technical user to the hobbyist.

pH calibration > Conductivity calibration > ORP validation > DO calibration >


We can help you keep your electrode running smoothly with our storage solutions.

Shop conditioning solutions >

Everything works together for the latest in testing technology.

edge® blu Wireless Tablet pH Meter works with any HALO to to help anyone get high quality pH and temperature results quickly and consistently. You can even connect your HALO to your smart phone or tablet for greater accessibility.

Speedsafe Magnetic Stirrers

Simple operation. Guaranteed better results.

Pro Grade Stirrers

Powerful. Reliable.



High performance; simplified.

Space Saving Stirrers

Small. Simple.



Color your busy benchtop for easy recognition.

Stir and Hold

Inclusive. Simple.



Hands-free; let the stirrer do the holding.


“Works great, I like that the housing is plastic, helps to avoid issues dealing with corrosion when working with strong acids. Good product, would recommend.” -Satu H.

Shop all stirrers >

pH Testing Tips

Clean Regularly.

Depending on the nature of your samples, your pH electrode can become dirty or clogged resulting in slow and faulty readings. Regular cleaning will prolong the life of your electrode.

Calibrate Often.

To ensure your pH measurements are accurate, be sure to calibrate after extended storage, cleaning, and before use. Use fresh buffers that bracket your expected value.

Condition Always.

A dry electrode results in slow, incorrect measurements. Always use proper storage solution and be sure to fully cover the junction.

To learn more, download our pH Best Practices Guide here!

Your pH Electrode

Pick the Right Tip Shape for Your Testing Needs.


A spherical tip is the most common shape for a pH electrode due to it's large surface area.
BEST FOR: aqueous samples and general purpose.


A cone shape makes testing of semi-solids easy.
BEST FOR: direct penetration into semi-solids, emulsions, soil, and slurries.

Flat Tip

The flat tip allows for the direct surface measurement of a sample.
BEST FOR: flat surfaces, skin, leather, and paper.


Finding the right electrode for specific testing can be tough. In order to help, Hanna Instruments has put together a guide, Getting To Know Your pH Electrode.

Do You Have the Right pH Buffers?

How do you know when calibration is necessary or why your readings are off?

An essential step in achieving accurate pH readings is proper calibration. A clean, calibrated, and conditioned pH electrode will provide accurate and repeatable results. When calibrating a pH electrode it is important to choose buffers that “bracket” (are above and below) the expected reading.

For example, if the expected reading is pH 5.4 then it would be best to calibrate to pH 4.01 and pH 7.01.

We manufacture a wide range of buffer solutions for a variety of uses. Visit our blog to find out What Type of pH Calibration Solution Should You Use?

Need help? These troubleshooting tips can help you out for those times when your pH electrode isn't working right.

Perform a pH Electrode Quality Test

Monitoring Slope and Offset

Important calibration values to monitor include slope and offset. These numbers provide information on the probe’s overall condition. The offset is the mV reading of the electrode when submerged in pH 7 buffer. Theoretically, the offset is 0 mV; however, the offset shouldn’t exceed ±30 mV. With edge®, the mV reading of the measured pH can be displayed on the LCD. The slope of the electrode is calculated by determining the mV change between two different pH buffers.

Hanna Tip: We recommend that you don't let the offset exceed ±30 mV and the slope percentage stays between 85-105%.

If you have a bad offset, this could mean that you either have a clogged junction or that the probe requires cleaning. If this occurs, try soaking the probe in a cleaning solution and repeat the process of checking offset. If your slope is bad, this could mean you have used expired or contaminated buffers. If this is the case, ensure that fresh buffers are used. edge's Calibration Check probe diagnostics feature will prompt you if there is a problem with your probe.

To learn more about how to calculate your slope and offset, Watch This Video.