Hanna HI12943 Direct Soil pH Electrode - Professional Soil & Soilless Media Testing
The Hanna HI12943 pH Electrode is engineered specifically for direct pH measurement in soil, soilless growing media, and semi-solid substrates. Designed exclusively for use with the HI9814 GroLine portable pH/EC/TDS meter, this professional-grade electrode features a triple ceramic junction, conic penetrating tip, and low-temperature glass formulation that delivers accurate, reliable pH readings in challenging soil and hydroponic applications.
Key Features
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Triple Ceramic Junction: 3x higher electrolyte flow rate (40-50 µL/hr) for faster, more stable readings
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Conic Tip Design: Penetrates soil, rockwool, coco coir, perlite, and semi-solid media
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Low-Temperature Glass: Optimized resistance for measurements from -5°C to 70°C
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Built-In Temperature Sensor: Automatic temperature compensation for accurate pH
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Integrated Amplifier: Pre-amplified signal reduces electrical noise
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Refillable Design: Extend electrode life with HI7071 fill solution
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Glass Body: Chemical resistant, fast thermal equilibrium
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Quick DIN Connector: Secure connection to HI9814 meter
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Wide pH Range: 0 to 13 pH measurement capability
Designed for Direct Soil Measurement
Unlike standard pH electrodes designed for liquid samples, the HI12943 is purpose-built for direct insertion into soil and soilless growing substrates. The specialized design considerations make it the ideal choice for:
- Garden soil and potting mixes
- Hydroponic growing media (rockwool, coco coir, perlite)
- Soil slurries and saturated paste extracts
- Semi-solid substrates and emulsions
- Agricultural field testing
- Greenhouse and nursery applications
Advanced Electrode Technology
Triple Ceramic Junction
The HI12943 features three ceramic junctions in contact with the sample, providing an electrolyte flow rate of 40-50 µL/hour—more than double the 15-20 µL/hour flow of standard single-junction electrodes. This increased flow rate provides greater continuity between the reference electrode and the indicating electrode, resulting in faster response times and more stable readings in difficult soil matrices.
Conic Bulb Design
The conical-shaped sensing tip allows for easy penetration into solids, semi-solids, and emulsions without damaging the glass bulb. This robust design is ideal for direct measurement of pH in soils, soil slurries, and dense growing media where standard spherical bulbs would be impractical or prone to breakage.
Low-Temperature Glass Formulation
The HI12943 uses a special low-temperature (LT) glass formulation with a lower resistance of approximately 50 megaohms compared to general-purpose (GP) glass at 100 megaohms. This lower resistance ensures optimal performance with the high-impedance input of pH meters, even when measuring samples at low temperatures from -5°C to 70°C. As temperature decreases, LT glass resistance increases but remains within the optimal range for accurate measurements.
Built-In Temperature Sensor & Amplifier
The integrated temperature sensor provides automatic temperature compensation (ATC) for pH readings, ensuring accuracy across varying soil temperatures. The built-in amplifier pre-amplifies the pH signal, reducing susceptibility to electrical noise from pumps, motors, and other equipment commonly found in greenhouse and grow room environments.
Refillable Design for Extended Life
As a refillable single-junction pH electrode, the HI12943 uses HI7071 3.5M KCl + AgCl fill solution. The refillable design allows you to maintain optimal electrode performance by replenishing the reference electrolyte as needed. When using the electrode, remove the fill cap to create positive head pressure in the reference cell, which increases electrolyte flow rate for faster, more stable readings.
Glass Body Construction
The glass body of the HI12943 offers several advantages for soil pH measurement:
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Chemical Resistance: Withstands exposure to fertilizers, nutrients, and soil amendments
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Easy Cleaning: Smooth glass surface prevents soil particle adhesion
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Fast Thermal Transfer: Rapid equilibrium with sample temperature for accurate readings
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Stable Reference Potential: Temperature-dependent mV generation stabilizes quickly
Technical Specifications
| Specification |
Detail |
| Model |
HI12943 |
| Measurement Range |
0 to 13 pH |
| Glass Type |
Low Temperature (LT) |
| Tip Shape |
Conic (penetrating) |
| Body Material |
Glass |
| Junction Type |
Triple Ceramic |
| Junction Flow Rate |
40-50 µL/hour |
| Reference Type |
Single, Ag/AgCl |
| Electrolyte |
3.5M KCl + AgCl (refillable) |
| Fill Solution |
HI7071 |
| Temperature Sensor |
Built-in (ATC) |
| Amplifier |
Integrated pre-amplifier |
| Operating Temperature |
-5 to 70°C (23 to 158°F) |
| Glass Resistance |
~50 megaohms (LT) |
| Connector Type |
Quick DIN |
| Compatible Meter |
HI9814 GroLine pH/EC/TDS Meter |
| Cable Length |
1 meter (3.3 feet) |
| Replaces |
HI1294D (fully compatible) |
Applications
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Agriculture: Field soil pH testing for crop management
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Hydroponics: Direct measurement in rockwool, coco coir, perlite substrates
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Horticulture: Potting mix and growing media pH monitoring
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Greenhouse Operations: Soil and substrate testing for optimal plant nutrition
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Nurseries: Container media pH verification
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Research: Soil science and agronomy studies
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Aquaponics: Growing bed substrate monitoring
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Soil Remediation: pH monitoring during treatment processes
Compatibility
Important: The HI12943 is designed exclusively for use with the Hanna HI9814 GroLine portable pH/EC/TDS meter. The Quick DIN connector, integrated amplifier, and built-in temperature sensor are optimized for this specific meter. This electrode will not work with other pH meters.
Note: The HI12943 replaces the HI1294D electrode. Both models are fully compatible with all versions of the HI9814 meter.
Measurement Procedure
- Remove the protective cap and fill cap from the electrode
- Rinse the electrode with distilled water
- Insert the conic tip directly into soil or growing media
- Allow reading to stabilize (typically 30-60 seconds)
- Record pH measurement from HI9814 meter
- Clean electrode thoroughly after use
- Store in HI70300 storage solution when not in use
Maintenance & Care
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Cleaning: Rinse with distilled water after each use; use HI7061 cleaning solution for stubborn soil deposits
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Refilling: Replenish with HI7071 fill solution when level drops below the internal reference element
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Storage: Store in HI70300 storage solution to keep glass membrane hydrated
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Calibration: Calibrate regularly using pH 4.01, 7.01, and 10.01 buffer solutions
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Junction Maintenance: If readings become slow or erratic, clean junctions with distilled water
Why Choose the HI12943?
Engineered by Hanna Instruments specifically for direct soil pH measurement, the HI12943 combines specialized design features that standard pH electrodes simply cannot match. The triple ceramic junction provides superior electrolyte flow for stable readings in difficult soil matrices, while the conic tip penetrates dense substrates without damage. The low-temperature glass formulation ensures accurate measurements across a wide temperature range, and the refillable design extends electrode life for long-term cost savings.
Whether you're managing a commercial greenhouse operation, conducting agricultural research, or maintaining a hydroponic growing system, the HI12943 delivers the professional-grade accuracy and durability you need for reliable soil pH testing.
Manufacturer: Hanna Instruments (GroLine Series)
SKU: HI12943
Origin: Romania
Replacement for HI1294D - Fully compatible with HI9814 meter
