Hanna Hi 98121 Temperature Tester Review

Examine and check your pool or spa’s pH, ORP (oxidation-reduction potential), and temperature with innovative Hanna HI 98121 temperature tester easily and quickly. Unlike a pH measurement that determines or quantifies how acidic or what the temperatures are or the overall condition of the water as having the capability to oxidize or decrease a chemical species.

It is a handheld, easy to use, and handy instrument for checking current conditions of pool water like the state of temperature, pH, ORP, etc. It also indicates probable contamination, especially by industrial wastewater.

This waterproof temperature or ORP tester is especially used for detecting water or any liquid temperature. It comes with a transparent display and its measured the temperature by using the probe and showed as a digital reading. It has an infrared sensor that quantifies temperature from a distance.

Key Features of Hanna HI 98121 Temperature Tester

The innovative, gorgeous-looking, and waterproof Hanna temperature tester are used to measure pool water temperature, pH, and ORP. It comes with a replaceable electrode and a non-clogging fiber junction.

The Hanna Instruments HI 98121 is a well-known option for operators a=carrying out spot checks or testing on location. When it comes to helping you to check and measure the water temperature, it comes with some fantastic and innovative characteristics.

Let’s see its exceptional features and benefits;

  • Specially designed for testing the temperature, ORP, and pH and a great option to check on the spot or testing on location.
  • Comes with one or two-point manual pH calibration for gaining results across a spacious range.
  • It is a waterproof combination pocket pH, ORP, and temperature that comes with a replaceable electrode to extend the meter lifespan.
  • Included Non-clogging renewable fiber junction.
  • Featured with a large LCD screen for easy readability.
  • Large and Dual-level LCDs that show the data of temperature and pH at one time.
  • Comes with self-activating temperature compensation and calibration.
  • Designed to work out in the field and fuzzy conditions.
  • The meter is sealed tightly with plastic wrap that helps to protect the tester against dampness. In one word, it is a humidity-proof tester.
  • The lightweight design helps to float in the water.
  • Comes with a bright and shiny green case that makes it visible in dark condition without facing any difficulty.
  • Hold function keep the readings for the comfort of recording.
  • Floating waterproof casing helps to prevent loss of meter during examining in worst conditions.
  • Battery percent level at startup and stability helps to assure tester is in highest working order.
  • The electrode replacement is engineered with stainless steel round connector that ensures there are no pins to bend or break the time of replacement.
  • Working range in temperatures of -5 to 60 Degree Celsius (23 to 140 Degree Fahrenheit) and has a range of -2 to 16 pH with a resolution of 0.01 pH.
  • Included accessories with the tester are; protective cap, calibration screwdriver, four LR44 1.5V batteries, instructions chart.
  • The item weight is 3.50 ounces and comes with two sets of the memorized buffer.

Is the temperature tester suitable for your needs?

Hanna instruments HI 98121 temperature tester review

Having this device is a great thing because it is an essential instrument to measure the water temperature, ORP, and pH levels of water. It helps you to check your pool water temperature instantly. It works efficiently and provides much better performance till the end.

Its lightweight design makes it portable to carry. The tester runs with an LR44 battery and saves your energy. The battery is included with the tester.


  • Comes with a replaceable electrode and non-clogging renewable fiber junction.
  • Waterproof and durable.
  • Simple and reliable tester and easy to use and carry.


  • Slightly difficult to use for a beginner.

Where to use the temperature tester?

It is used to test and check the temperature, pH, and ORP of water or solid materials. It is an instrument that helps to measure temperature. It can measure the temperature of solids like food, liquids like water, or gases like air. Especially it can measure the temperature of other bodies of water and testing for bonding between water temperature and the features of the water.

How you use the temperature or pH, or ORP tester?

The Hanna Instruments HI 98121 Temperature tester is simple to use and control. You just need to follow the manufacturer’s instructions and get it done. Firstly, place the temperature tester under the tongue.

Then hold the tester in the same spot for about 40 t0 45 seconds. Typically, the tester will make a smooth noise or notify you when the final reading is done. It takes only 30 seconds.

How does the Hanna Instruments HI 98121 Temperature tester stand out in the competition?


This temperature tester is designed to work in the field in obscure conditions and for swimming pools or spas. The meter is sealed or wrapped with durable and humidity-proof glass and helps to float in the water. It offers the user a choice of ORP or redox, pH, and temperature measurement combinations.

It is a fantastic and well-known option for operators carrying out spot checks and examining on location. It comes with Replaceable pH or ORP electrode cartridge and non-clogging renewable fiber junction to extend the meter lifespan. A large bright screen LCD helps to read out the data easily.


The HI 98121 Temperature tester is made by Hanna Instruments manufacturer who is well-known to make analytical instruments including pH meters, multi-parameters, electrodes, chemical reagents, and many more. They are known to provide quality products. This temperature is made with rigid plastic and the meters are sealed against humidity. Also, it is a waterproof device that lasts longer.


It is a waterproof combination pocket pH, ORP, and temperature tester that is easy to use and manage. You just need to follow the instructions that are included with the tester by the manufacturer.

How the HI 98121 temperature tester improved? –HI 98121 VS HI 98120

HI 98121 is an upgradable and latest version of HI 98120 temperature tester. As it is an updated version it includes lots of unique features. With this comparison between these two models, you can identify the differences.

Let’s start;

  • HI 98121 has a non-clogging renewable fiber junction and replaceable electrode whereas HI 98120 comes with an extractable junction.
  • HI 98121 is lighter (3.50 ounces) than HI 98120 (3.53 ounces) temperature or ORP tester.
  • With HI 98121 manufacturer included a calibration screwdriver but HI 98120 has no calibration screwdriver.

See also:

  1. Bluelab METCOM Combo Meter for pH Review | Easy Calibration
  2. Bluelab CONTPHCON pH Controller review
  3. Extech CL200 Exstik waterproof chlorine meter review
  4. Pentair Easy Touch 520593 4PSC-IC40 Pool & Spa controller
  5. Easy Touch Pentair, pool & Spa Automated Control System