Hanna Instruments HI 99121 Soil pH Meter, Item #51600
The Hanna Instruments HI 99121 Soil pH Meter, Item #51600, is a portable direct soil pH and temperature meter designed for field and laboratory-style spot testing of soil conditions. It is purpose-built for agricultural, horticultural, greenhouse, turf, nursery, and environmental users who need a fast, dependable method for measuring soil pH directly at the point of use. Rather than relying solely on bench workflows, the HI99121 enables direct insertion into soil and also supports soil slurry testing where a prepared sample method is preferred.
The meter is supplied with Hanna’s HI12923 dedicated soil pH/temperature probe, which is specifically engineered for soil analysis. The probe incorporates a rugged conical glass tip to support penetration into soil and semi-solid media, an open junction design to reduce clogging from organic matter, and a built-in temperature sensor for automatic compensation during measurement. Hanna also includes a ground auger to loosen harder soils before measurement, helping protect the sensing glass and improve field usability.
This platform is well suited for routine fertility assessment, root-zone monitoring, amendment verification, greenhouse media checks, and general agronomic troubleshooting. For operations that need portable, application-specific soil pH verification without overcomplicating the workflow, the HI99121 is positioned as a straightforward and durable field instrument.
Product Capabilities
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Measures pH and temperature simultaneously on a dual-line LCD display.
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Supports direct soil measurement and soil slurry testing.
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Provides automatic one- or two-point pH calibration with standard or NIST buffer sets.
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Includes automatic temperature compensation for more reliable readings across changing conditions.
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Offers pH-mV mode for electrode check and verification.
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Uses the HI12923 dedicated preamplified soil probe with integrated temperature sensor.
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Features an electrode condition indicator for quick diagnostic feedback.
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Includes battery life indication and low battery detection.
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Provides user-selectable auto-off after 8 minutes, 60 minutes, or disabled.
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Uses an IP67 waterproof housing for rugged field use.
Industries of Use
Agriculture
Horticulture
Greenhouse operations
Nurseries
Turf management
Landscaping
Environmental field testing
Soil science research
Academic and extension programs
Key Benefits
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Direct soil measurement reduces testing time in the field.
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Dedicated soil probe improves fit-for-purpose performance in soil and slurry applications.
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Open junction design helps limit clogging from soil organics and debris.
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Automatic temperature compensation improves reading consistency.
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Portable IP67 construction supports demanding field conditions.
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Long battery life supports extended sampling cycles and seasonal use.
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Included auger and cleaning solutions support better field workflow and probe care.
Features:
Direct Soil Measurement
The HI99121 is engineered specifically for direct soil pH testing and can also be used for soil slurry measurements when a prepared sample workflow is required.
Dedicated HI12923 Soil Probe
The included HI12923 probe is purpose-built for soil analysis and features a rugged conical glass tip, integrated temperature sensor, and preamplified design for dependable field performance.
Open Junction Construction
The probe’s open junction design helps reduce clogging from organic material and soil contamination, supporting more stable readings and lower maintenance demand.
Automatic Temperature Compensation
The built-in temperature sensor automatically compensates pH readings for temperature variation, improving consistency across changing field and greenhouse conditions.
Portable IP67 Meter Body
The compact handheld meter is sealed to IP67 for protection against dust and water intrusion, making it well suited for routine outdoor and jobsite use.
Fast Calibration and Diagnostics
Automatic one- or two-point calibration, electrode condition indication, low battery alerts, and pH-mV check mode help users maintain confidence in data quality.
Applications:
Direct field soil pH testing
Soil slurry pH analysis
Crop fertility monitoring
Root-zone pH assessment
Greenhouse growing media checks
Nursery substrate verification
Turf and landscape soil management
Soil amendment verification
Irrigation impact evaluation
Agronomy research sampling
Environmental soil screening
Routine soil condition spot checks
Specifications – Item #51600
| Product Name | Hanna Instruments HI99121 Soil pH Meter |
| Item # | 51600 |
| Model | HI99121 |
| Product Type | Portable waterproof pH and temperature meter for direct soil measurement |
| Primary Application | Direct pH measurement in soil and soil slurries |
| pH Range | -2.00 to 16.00 pH / -2.0 to 16.0 pH |
| pH Resolution | 0.01 pH / 0.1 pH |
| pH Accuracy | ±0.02 pH / ±0.1 pH |
| mV Range | ±825 mV (pH-mV) |
| mV Resolution | 1 mV |
| mV Accuracy | ±1 mV |
| Temperature Range | -5.0 to 105.0 °C / 23.0 to 221.0 °F |
| Temperature Resolution | 0.1 °C / 0.1 °F |
| Temperature Accuracy | ±0.5 °C up to 60 °C and ±1.0 °C outside / ±1.0 °F up to 140 °F and ±2.0 °F outside |
| Temperature Compensation | Automatic |
| pH Calibration | Automatic, 1 or 2 point, Standard or NIST buffer sets |
| Included Probe | HI12923 preamplified pH and temperature probe with conical tip and 1 m (3.3 ft) cable |
| Probe Features | Conical glass tip, integrated temperature sensor, preamplifier, open junction design |
| Ingress Protection | IP67 |
| Power Supply | 1.5V AAA batteries (3 pcs.) |
| Battery Life | Approx. 1400 hours of continuous use |
| Auto-Off | User selectable after 8 minutes, 60 minutes, or disabled |
| Operating Environment | 0 to 50 °C (32 to 122 °F), RH max 100% |
| Dimensions | 154 x 63 x 30 mm (6.1 x 2.5 x 1.2 in.) |
| Weight | 196 g with batteries |
| Included Accessories | HI12923 probe, pH 4.01 and 7.01 buffer sachets, soil and humus cleaning solutions, HI7051M soil preparation solution, HI721319 auger, 100 mL beaker, batteries, carrying case, meter certificate, electrode certificate, instruction manual |
| Warranty | 2 years |