Hanna Instruments GroLine pH/EC/TDS Multiparameter Replacement Probe for use with HI981421

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.

PVC Body
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