Hanna Instruments Direct Soil and Soilless Media pH electrode for use with HI9814

SKU: HI12943

215.00 215.0 USD 215.00


This pH electrode for the HI9814 Groline portable pH/EC/TDS meter is well designed for direct measurement of pH in soil and soilless media.

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    Hanna Instruments Direct Soil and Soilless Media pH electrode for use with HI9814

    The HI12943, a glass body, refillable, single junction pH electrode with a quick connect DIN connector, is designed for use with Hanna’s HI9814 GroLine portable pH/EC/TDS meter. This electrode has a triple ceramic junction in the outer reference cell and the conic pH sensing tip is made with low temperature glass. There is an integrated amplifier and built-in temperature sensor for automatically temperature-compensated pH readings.

    The design consideration for the HI12943 is ideal for pH measurements in soils and soil slurries and for soilless media including rockwool, coco coir, and perlite. The HI12943 

    • Triple Ceramic Junction
    • Low Temperature Glass
    • Built-in Temperature Sensor

    Hanna Instruments offers a wide variety of pH electrodes that are designed for many different applications. The type of glass used for sensing pH, bulb shape, body material, type of junction, type of reference, and electrolyte used are just some of the design considerations.

    The HI12943 uses low temperature (LT) glass, conic bulb, glass body, and triple ceramic junction, and is refillable with 3.5M KCl + AgCl.

    Low Temperature Glass Formulation

    The glass tip uses a special LT glass formulation with a lower resistance of approximately 50 megaohms compared to general purpose (GP) with a resistance of about 100 megaohms.  As the temperature of the glass decreases when in a sample at low temperature, the resistance of the LT glass will increase approaching that of GP glass at ambient temperatures. If using GP glass, the resistance would increase above the optimum resistance for the high impedance input of a pH meter. The HI12943 is suitable to use with samples that measure from -5 to 70oC.

    Conic Bulb

    The conical shaped tip design allows for penetration into solids, semi solids, and emulsions. The HI1294D is ideal for the direct measurement of pH in soils, hydroponic soilless media, and soil slurries.

    Glass Body

    The glass of the HI12943 is resistant to many harsh chemicals and is easily cleaned. The glass body also allows for a fast transfer of heat to the internal reference electrolyte. The mV generated by the reference cell is temperature dependent. The faster the equilibrium the steadier the reference potential.

    Triple Ceramic Junction

    The triple ceramic junction allows a higher flow rate of electrolyte from the reference cell into the measurement sample. A typical pH electrode will have a single ceramic junction that flow rate of 15 to 20 µL/hour. The HI12943 has three ceramic junctions in contact with the sample providing a flow rate of 40 to 50 µL/hour. The increased flow provides a greater continuity between the reference electrode and the indicating electrode.


    The HI12943 is a refillable probe. Since it is a single junction pH electrode the fill solution is the HI7071 3.5M KCl + AgCl. If using a refillable pH electrode, the fill cap should be removed prior to calibration and measurement. Removing the cap creates positive head pressure in the reference cell allowing for a higher flow rate of electrolyte through the outer junction. A higher flow rate will result in a faster and more stable reading.

    Quick Connect DIN Connector

    The HI12943 has a quick connect DIN connector that can be used only with the HI9814 GroLine portable pH/temperature meter.

    Weight (lbs)1
    Length (in)11.75
    Width (in)2
    Height (in)7.5
    Reference Cell Typesingle, Ag/AgCl
    Junction Type/Flow Rateceramic, triple / 40-50 μL/h
    Refill Electrolyte3.5M KCl + AgCl
    Body Materialglass
    Glass Typelow temperature (LT)
    Tip / Shapeconic (12 x 12 mm)
    Matching Pinno
    Max. Pressure0.1 bar
    Optimum pH RangepH
    Temperature Operating Range-5 to 70°C (23 to 158°F) - LT
    Body Length/Overall Length120 mm / 175.5 mm
    Temperature Sensoryes
    Outer Diameter12 mm
    Cable7-pole; 1 m (3.3')
    Connector Typequick connect DIN
    Recommended Usedirect soil pH measurement, soil samples, soil solution
    NotesThis probe is only compatible with the HI9814 portable pH/EC/TDS meter.