Hanna Instruments offers a wide variety of electrodes that are designed for many different applications. The sensing material, body material, and connection type used are just some of the design considerations.
Pre-Amplified pH Electrode
The pH electrode circuit has a built-in amplifier that serves to reduce the effects of electrical noise on the high impedance pH measurement. Electrical noise can come from motors and pumps that are common in greenhouses. The single reference junction design of the pH electrode has a cloth junction that allows ion movement between the inner gel electrolyte and the sample being measured. The advantage of the cloth junction is that it can be extracted from the probe, exposing a fresh surface when readings become drifty or erratic. These features make this probe ideal for use in fertilizer solutions.
Amperometric EC/TDS Sensor
EC/TDS readings are performed by a two-pin amperometric sensor. An alternating voltage is applied to the sensor and the amount of current that passes between the two stainless steel pins determines the amount of dissolved ionic solids present.
Built-In Temperature Sensor
pH and EC/TDS readings must be temperature compensated in order to obtain accurate results. The built-in temperature sensor of the HI1285-8 provides a speedy temperature reading which is then used to adjust the pH and EC/TDS results accordingly.
The PVC body of the HI1285-9 houses all three sensors within a sturdy, single body design. This body material is suitable for a wide range of applications and excels in harsh grow environments due to its durability. PVC is chemically resistant to many aggressive chemicals and minimizes breakage due to accidental bumping or dropping of the electrode.
The HI1285-9 uses a DIN connector. This probe is recommended for use with the HI981421 GroLine Hydroponic Nutrients Monitor for pH, EC, TDS, and Temperature.
Measurement Range pH: 0 to 12, EC Junction Type/Flow Rate PTFE Type of Electrolyte polymer Body Material PVC (thread 3/4” NPT) Tip / Shape dome Matching Pin yes Max. Pressure 8 bar Temperature Operating Range 0 to 60°C (32 to 144°F) - GP Overall Length 190 33 Temperature Sensor yes Outer Diameter 32 mm Cable 7-pole; 3 m cable (9.9’) Connector Type DIN Amplifier yes Recommended Use Hydroponics, Aquaponics, and Greenhouses