Hanna HI1285-9 GroLine Inline Multiparameter Probe - pH, EC, TDS & Temperature Sensor
The Hanna HI1285-9 GroLine Inline Multiparameter Probe measures pH, EC/TDS, and temperature in one convenient, rugged probe designed specifically for continuous monitoring in hydroponic nutrient solutions. This specialized inline probe is engineered for use with the HI981421 GroLine Monitor to provide around-the-clock monitoring of critical water quality parameters in hydroponics, aquaponics, and greenhouse applications.
Complete 4-in-1 Sensor Solution
The HI1285-9 combines four essential sensors in a single rugged probe body: pre-amplified pH electrode, amperometric EC/TDS sensor, built-in temperature sensor, and DIN connector for secure, waterproof connection to the HI981421 monitor. This all-in-one design simplifies installation and reduces the number of probes needed for comprehensive nutrient solution monitoring.
Key Benefits
-
4-in-1 Design: pH, EC, TDS, and temperature measurement in one probe
-
Pre-Amplified pH Electrode: Reduces electrical noise from pumps and motors
-
PTFE Non-Clogging Junction: Exclusive membrane prevents clogging in fertilizer solutions
-
Renewable Junction: Cloth junction can be extracted for extended probe life
-
Built-In Temperature Sensor: Fast, accurate temperature compensation
-
Inline Design: Mounts directly in-line with nutrient flow
-
Rugged PVC Body: Durable construction withstands harsh grow environments
-
DIN Connector: Secure waterproof connection to HI981421 monitor
Advanced Sensor Technology
Pre-Amplified pH Electrode
The pH electrode circuit features a built-in amplifier that significantly reduces the effects of electrical noise on the high-impedance pH measurement. Electrical noise from motors, pumps, and ballasts is common in greenhouses and grow rooms—the pre-amplified design ensures stable, accurate pH readings even in electrically noisy environments.
The single reference junction design features a cloth junction that allows ion movement between the inner gel electrolyte and the sample being measured. The key advantage of the cloth junction is that it can be extracted from the probe, exposing a fresh surface when readings become drifty or erratic. This renewable junction design extends probe life and reduces replacement costs, making it ideal for long-term use in fertilizer solutions.
Amperometric EC/TDS Sensor
EC/TDS readings are performed by a precision 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 concentration of dissolved ionic solids present in the nutrient solution. This proven technology delivers accurate, reliable conductivity measurements for precise nutrient management.
Built-In Temperature Sensor
pH and EC/TDS readings must be temperature compensated to obtain accurate results. The built-in temperature sensor of the HI1285-9 provides a speedy temperature reading which is then used to automatically adjust the pH and EC/TDS results accordingly. This ensures accurate measurements even during sudden temperature fluctuations common in grow environments.
PTFE Non-Clogging Junction
The exclusive PTFE (polytetrafluoroethylene) junction membrane prevents clogging from organic materials and fertilizer deposits commonly found in hydroponic nutrient solutions. This advanced junction design maintains consistent performance and extends the time between cleanings, reducing maintenance requirements.
Durable Construction
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 exceptional durability. PVC is chemically resistant to many aggressive chemicals and minimizes breakage due to accidental bumping or dropping of the probe—critical for long-term reliability in commercial operations.
DIN Connector
The HI1285-9 uses a professional DIN connector that creates a waterproof seal with the HI981421 monitor. This secure connection is ideal for reducing electrical noise issues caused by humid grow room environments while ensuring reliable signal transmission.
Technical Specifications
| Specification |
Detail |
| Model |
HI1285-9 |
| Measurement Parameters |
pH, EC, TDS, Temperature |
| pH Range |
0 to 12 pH |
| Reference |
Triple, Ag/AgCl |
| Junction Type |
PTFE (non-clogging) |
| Electrolyte |
Polymer gel |
| Max Pressure |
8 bar |
| Operating Temperature |
0 to 60°C (32 to 140°F) |
| Tip Shape |
Dome |
| Temperature Sensor |
Built-in |
| Amplifier |
Pre-amplified pH circuit |
| Body Material |
PVC |
| Cable |
7-pole, 1 m (3.3') |
| Connection |
DIN connector |
| Recommended Use |
Hydroponics, aquaponics, greenhouses |
| Compatible Monitor |
HI981421 GroLine Monitor |
Applications
-
Hydroponic Systems: Continuous monitoring of nutrient solution pH and EC/TDS
-
Aquaponic Systems: Water quality monitoring for fish and plant health
-
Greenhouse Operations: Automated nutrient management and irrigation control
-
Commercial Grow Facilities: Professional-grade monitoring for consistent yields
-
Research Applications: Precise data collection for agricultural studies
-
Nursery Operations: Fertilizer solution monitoring and control
Compatibility
Important: The HI1285-9 probe is specifically designed for use with the HI981421 GroLine Hydroponic Nutrients Monitor. The 7-pole DIN connector and pre-amplified design are optimized for this monitor. Ensure compatibility before ordering.
Installation
The inline design allows the HI1285-9 to be mounted directly in-line with your nutrient recirculation system. The probe can be installed in a flow cell or inline tee fitting for continuous monitoring. The 1-meter cable provides flexibility for mounting the HI981421 monitor in a convenient location.
Maintenance
Regular maintenance ensures optimal performance:
- Clean the probe periodically to remove nutrient deposits
- Extract and replace the cloth junction when readings become slow or erratic
- Calibrate the pH electrode regularly using pH 4.01, 7.01, and 10.01 buffer solutions
- Calibrate EC/TDS using 1.41 or 5.00 mS/cm standard solutions
- Inspect the PTFE junction for clogging and clean as needed
Why Choose the HI1285-9?
Engineered by Hanna Instruments specifically for continuous hydroponic monitoring, the HI1285-9 delivers professional-grade accuracy in a rugged, all-in-one probe design. The combination of pre-amplified pH electrode, PTFE non-clogging junction, renewable cloth junction, and built-in temperature compensation makes it the ideal replacement or upgrade probe for the HI981421 GroLine Monitor. Perfect for commercial growers, research facilities, and serious hobbyists who demand reliable, long-term performance.
Manufacturer: Hanna Instruments (GroLine Series)
Country of Origin: Romania
SKU: HI1285-9
Note: This probe is designed specifically for the HI981421 GroLine Monitor. Verify compatibility before ordering.
