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Hanna pH Meter - HI98100 Checker Plus


Item #: HN98100

In Stock

Hanna Instruments Checker Plus pH Tester HI98100

The HI98100 Checker Plus is the next generation of the original Hanna Checker pH tester. The Checker is the most popular pH meter in the world with over 1 million meters used since its introduction in 1991. From students to researchers, the Checker has been helping people with their pH measurement as a meter that is simple to use and operate. A replaceable electrode extends the life of your digital pH tester.

  •     ±0.2 pH accuracy 
  •     Comes with all the necessary solutions and batteries- everything you need to get started measuring right away.
  •     Great for environmental, field, and laboratory testing.

The main difference between the HI98100 and HI98103 is the Checker Plus HI98100 has PH resolution to the 0.01. The HI98103 only measure`s ph to the tenth 0.1. The Checker Plus HI98100 also has automatic calibration to one or two points, automatic buffer recognition, calibrated buffer tags, stability indicator, low battery indicator, and select-able automatic shut off.

Features at-a-glance:

  • Economical – The Checker Plus is a full-featured pH tester at a price that anyone that needs to measure pH can afford. Large LCD - Enhanced LCD that displays reading, stability indicator, low battery indicator and calibration tags.
  • Replaceable pH Electrode - The HI1271 supplied gel filled pH electrode is 103 mm long and tapers to an 8 mm diameter at the sensing end. This narrow electrode easily fits into test tubes, vials, and other containers with small opening.
  • Automatic Calibration - The Checker Plus is calibrated automatically to one or two points. The calibration buffers are automatically recognized and after calibration the buffer values used are shown on the display as a tag.
  • Stability Indicator – An hourglass indicator is displayed on the LCD until a stable reading is obtained. Once a reading stabilized the indicator disappears and a reading can be recorded.
  • Automatic Shut-Off – The meter can be set to automatically turn off after 8 minutes or 60 minutes to conserve battery life in the event that the meter is left on. The auto off feature can be disabled.
  • Long Battery Life - The Checker Plus has an exceptional long battery life of approximately 1000 hours. When the battery power is running low a low battery indicator is displayed.
  • Plastic Carrying Case – The HI98100 Checker Plus is supplied complete with meter, probe, calibration solutions and cleaning solutions packaged in a durable plastic carrying case.


pH Range0.00 to 14.00 pH
pH Resolution0.01 pH
pH Accuracy (@25ºC/77ºF)±0.2 pH
CalibrationAutomatic, one or two points with three standard buffers available (pH 4.01, 7.01 and 10.01)
Battery Type/Life1.5V CR2032 (1) / approximately 1000 hours of continuous use
Electrode/ProbeHI1271 pH electrode with screw type connector (included)
Environment0 to 50°C (32 to 122°F); RH max 95%
Dimensions50 x 174 x 21 mm (2 x 6.8 x 0.9”)
Weight50 g (1.8 oz.) 
Ordering Information

HI98100 is supplied with:

  • HI1271 pH electrode
  • HI70004 pH 4.01 buffer solution sachets (2 x 20 mL)
  • HI70007 pH 7.01 buffer solution sachets (2 x 20 mL)
  • HI700601 electrode cleaning solution sachets (2 x 20 mL)
  • Instruction manual
  • Instrument quality certificate and plastic carrying case.
Warranty1 Year (pH probe 6 months)

Manufacturer information

Hanna Instruments USA Aquarium Supplies
Hanna Instruments is a leading manufacturer of analytical aquarium instrumentation. They were founded in 1978 and are headquartered in Woonsocket, Rhode Island. When Hanna introduced pH Electronic Paper in 1986 it literally revolutionized the world of testing by allowing millions of people in various industries to test for pH in a simple, accurate and affordable way. Hanna employees are constantly challenging themselves to improve on existing technology and to invent new testing techniques with the common goal to simplify analytical testing. This applies not only to instrumentation, but also to sensors development, reagents and chemicals. Hanna also believes in controlling the quality of their products from inception to delivery so they manufacture everything themselves, from meters and electrodes to chemical reagents and buffer solutions.

4 Stars


Reviewed on
July 11, 2019

Yes, I would recommend this.

Buy the better PHeP by Hanna

Pros: price

Cons: breaks easily.

I do not understand why Hanna made this pen. Sure when you get it and calibrate it everything is new and exciting. This pen electrode needs to be kept moist at all times. I bought the storage agent and it dried up anyways after a short time. Lower cost entry point but the drying up makes the pen worthless. I replaced it with the PHeP by Hanna. It is by far the best one on the market. More accurate than this one and much more relaible

Was this review helpful? 7 0


Reviewed on
March 26, 2019

Yes, I would recommend this.

Great PH tester

Pros: Easy to read and calibrate.

Cons: none

Easy to use and accurate reading.

Was this review helpful? 0 1


Reviewed on
March 26, 2019

No, I would not recommend this.


Pros: When it works it does provide a good reading.

Cons: Needs storage solution, sometimes does not read and requires resetting.

This particular pH is not the easiest checker to calibrate and use. It also requires solution drops for storage that do not come with the unit and it was not clear you needed this until after delivery of product. Probably should have picked a higher priced pH version from This manufacturer.

Was this review helpful? 4 0


Reviewed on
January 26, 2019

Yes, I would recommend this.

So easy to use

So simple and easy to use. I don't no why i didnt buy sooner

Was this review helpful? 1 0


Reviewed on
August 11, 2018

Yes, I would recommend this.

Works Great!

Pros: Quick easy and accurate

Cons: None

Love the ph checker plus! No more color matching or counting drops. Calibrate, stick in tank and boom precise reading! Only regret not buying the Hanna testers a long time ago.

Was this review helpful? 3 0


Reviewed on
March 13, 2018

Yes, I would recommend this.

Hanna does it again

Pros: Quick and accurate

So much easier than any chemical test just put it in the water and boom an accurate reading, and at a really fair price.

Was this review helpful? 3 0


Reviewed on
October 28, 2017

Yes, I would recommend this.

Easy to use

Pros: Quick reading, price is fair

Cons: Initial calibration was a little confusing but still took less than 10 min

I have been using this for about a month. It is a great product seems to be very accurate and of course better than deciphering a titration style test kit

Was this review helpful? 1 0


Reviewed on
May 15, 2017

Yes, I would recommend this.


Pros: Digital, accurate

Cons: non

Works pretty good and as far as I can tell is accurate. Should come with storage solution but it doesn't. Overall I'm happy with it. would be 5 stars with storage solution.

Was this review helpful? 2 0

robert mcdonald

Reviewed on
July 25, 2016

Yes, I would recommend this.

Works Good

Works much easier then the previous generations

Was this review helpful? 0 0

tim sabo

Reviewed on
June 09, 2016

Yes, I would recommend this.

Hanna pH Checker

This pH checker works great. A lot easier than chemical test kits.

Was this review helpful? 1 0

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