Product Description
Professional-grade pH and temperature testing in a compact, waterproof pocket design. The Hanna HI98128 pHep®5 delivers laboratory-accurate measurements with 0.01 pH resolution and ±0.05 pH accuracy, featuring automatic calibration, temperature compensation, and a replaceable electrode system that extends the life of your tester for years.
Key Features & Benefits
High precision 0.01 pH resolution – Professional accuracy of ±0.05 pH for reliable results
Waterproof & floats – IP67 rated, designed to float if dropped in water
Replaceable electrode – HI73127 cartridge design with extractable cloth junction extends tester life
Auto calibration – One, two, or three-point automatic calibration with dual buffer sets
Temperature compensation – Automatic ATC displays pH and temperature (°C or °F) simultaneously
Extended pH range – Measures from -2.00 to 16.00 pH for versatile applications
Long battery life – Up to 300 hours continuous use with 4 AAA batteries
Portable & durable – Pocket-sized design perfect for field testing and on-the-go measurements
Why Choose the pHep®5?
The HI98128 pHep®5 combines advanced features typically found in expensive portable instrumentation with the convenience and affordability of a pocket tester. The innovative replaceable electrode design features a stainless steel round connector with no pins to align or break, making electrode replacement quick and foolproof. The extractable cloth junction can be renewed by simply pulling out ⅛" of material, clearing any clogging and restoring response time without replacing the entire electrode.
Advanced Features for Confident Testing
Waterproof Design
IP67 waterproof rating protects against water immersion
Designed to float if accidentally dropped in a tank or water body
Ideal for wet environments, field testing, and marine applications
Expanded pH Range
Measures from -2.00 to 16.00 pH – handles extreme acidic and alkaline solutions
Perfect for diverse applications from aquariums to industrial testing
Automatic Temperature Compensation (ATC)
All pH readings automatically compensated for temperature variations
Simultaneous display of pH and temperature in °C or °F
Temperature range: -5.0 to 60.0°C (23.0 to 140.0°F)
Temperature accuracy: ±0.5°C / ±1°F
Stability Indicator
On-screen clock icon disappears when reading achieves stability
Ensures accurate, reliable measurements every time
HOLD Button
Freezes reading on display for easy recording and documentation
Perfect for logging measurements in challenging environments
BEPS (Battery Error Prevention System)
Automatically shuts off if battery power is insufficient for accurate measurement
Prevents false readings due to low battery
Auto-Off Function
Automatically powers down after 8 minutes of non-use
Maximizes battery life and prevents accidental drain
Flexible Calibration Options
The pHep®5 offers automatic one, two, or three-point calibration with two selectable buffer sets for maximum flexibility:
Buffer Set 1: pH 4.01, 7.01, 10.01
Buffer Set 2: pH 4.01, 6.86, 9.18
Choose the buffer set that best matches your testing requirements and application.
Replaceable Electrode System
The HI73127 pH electrode features an innovative cartridge design with a stainless steel round connector – no fragile pins to align or break. The extractable cloth junction allows you to renew the junction by simply pulling out ⅛" of material, clearing clogs and restoring fast response time. This extends electrode life significantly, reducing long-term costs.
Complete Kit - Ready to Test
Your HI98128 pHep®5 arrives with everything needed for immediate testing:
HI73127 replaceable pH electrode
HI73128 electrode removal tool
pH 4.01 buffer solution sachets (2 × 20 mL)
pH 7.01 buffer solution sachets (2 × 20 mL)
HI700601 electrode cleaning solution sachet (20 mL)
HI70300N storage solution sachet (20 mL)
1.5V AAA batteries (4 pcs.)
Instrument quality certificate
Instruction manual
Technical Specifications
Specification
Detail
SKU
HI98128
pH Range
-2.00 to 16.00 pH
pH Resolution
0.01 pH
pH Accuracy (@25°C/77°F)
±0.05 pH
pH Calibration
Automatic, at one, two, or three points with two sets of standard buffers (pH 4.01/7.01/10.01 or pH 4.01/6.86/9.18)
pH Temperature Compensation
Automatic (ATC)
Temperature Range
-5.0 to 60.0°C / 23.0 to 140.0°F
Temperature Resolution
0.1°C / 0.1°F
Temperature Accuracy
±0.5°C / ±1°F
pH Electrode
HI73127 replaceable pH electrode with extractable cloth junction
Automatic Shut-Off
Auto-off after 8 minutes of non-use
Battery Type / Life
1.5V AAA (4) / Approximately 300 hours of continuous use
Environment
-5 to 50°C (23 to 122°F); RH max 100%
Waterproof Rating
IP67 (waterproof and floats)
Dimensions
163 × 40 × 26 mm (6.4 × 1.6 × 1.0")
Weight
100 g (3.5 oz.)
Applications
Aquariums and aquaculture
Hydroponics and agriculture
Water quality testing
Swimming pools and spas
Laboratory and educational use
Food and beverage production
Environmental monitoring
Marine and reef keeping
Wastewater treatment
Why Hanna Instruments?
Hanna Instruments is a world leader in analytical instrumentation, trusted by professionals in over 140 countries. The pHep®5 represents decades of innovation in portable pH testing, combining professional accuracy with user-friendly operation and exceptional value.
