The Bluelab ORP Meter is a portable digital instrument for measuring oxidation-reduction potential (ORP) in water and nutrient solutions. Designed for growers and horticultural professionals, it provides reliable millivolt (mV) measurements to help monitor water quality, disinfection conditions, and changes in solution chemistry.
With its compact handheld design, easy-to-read backlit display, and dedicated ORP sensor, the meter makes routine testing convenient throughout hydroponic, greenhouse, and irrigation systems. Its replaceable probe and straightforward operation make it a practical addition to professional water-quality monitoring programs.
Monitor the Oxidative Conditions of Your Water. Track ORP in millivolts to better understand water conditions and support informed water-treatment and system-management decisions.
Key Features
Precise Millivolt Readings
Measure oxidation-reduction potential across a ±1000 mV range with 1 mV resolution for detailed monitoring of water conditions.
Compact & Easy to Use
A handheld design, bright backlit display, and simple controls make routine testing convenient across growing facilities.
Replaceable ORP Sensor
A durable probe with standard BNC connection and 2-metre cable supports flexible measurements and straightforward replacement.
Optional pH Measurement
The meter also supports pH measurement when connected to a compatible Bluelab pH Probe, available separately.
Better Insight into Water Quality
Water quality plays an important role in the performance of hydroponic and greenhouse growing systems. Beyond measuring pH and conductivity, understanding oxidation-reduction potential provides additional insight into the chemical conditions of water.
ORP measures the tendency of a solution to gain or lose electrons. Higher positive ORP readings generally indicate more oxidizing conditions, while lower readings indicate comparatively reducing conditions.
Tracking ORP helps growers identify changes in water chemistry and monitor conditions associated with water-treatment and disinfection processes.
Why Oxidation-Reduction Potential Matters
Monitor Water-Treatment Conditions
In water systems using oxidizing disinfectants, ORP measurements can provide useful information about the overall oxidative environment. Monitoring changes over time can support treatment-process evaluation.
Identify Changes in System Conditions
Recirculating nutrient and irrigation systems can experience changes in water chemistry during operation. Routine ORP measurements allow operators to establish reference readings and recognize deviations from typical conditions.
Complement pH and EC Monitoring
ORP adds another useful parameter to a broader water-quality monitoring program. When considered alongside pH, conductivity, temperature, and appropriate water-treatment testing, it can support more informed system management.
Important: ORP is not a direct measurement of disinfectant concentration or microbial contamination. Readings should be interpreted in the context of the specific water chemistry and treatment process.
Applications
- Hydroponic systems: Monitor oxidation-reduction conditions in nutrient solutions and water circuits.
- Greenhouse irrigation: Track ORP trends in irrigation-water systems.
- Water treatment: Support monitoring of appropriate oxidation-based disinfection processes.
- Recirculating reservoirs: Compare readings across different sampling points and operating conditions.
- Horticultural research: Incorporate ORP measurements into water-quality monitoring and evaluation.
Built for Practical, Everyday Testing
The Bluelab ORP Meter combines a compact handheld instrument with a dedicated platinum-electrode ORP Probe. The 2-metre (6.6-foot) cable provides flexibility when testing reservoirs, tanks, and other accessible water sampling locations.
The probe features a platinum spiral electrode, ceramic diaphragm, double-junction construction, and a standard BNC connector. Its storage cap helps protect the sensing components between uses.
The backlit digital display allows readings to be checked easily, while the auto-off function helps conserve battery power.
Product Specifications & Documentation
Technical Specifications
| Product | Bluelab ORP Meter |
|---|---|
| SKU | METORP |
| Manufacturer | Bluelab |
| Primary Measurement | Oxidation-Reduction Potential (ORP) |
| Measurement Unit | Millivolts (mV) |
| ORP Range | ±1000 mV |
| ORP Resolution | 1 mV |
| ORP Accuracy | ±5 mV at 25°C (77°F) |
| Optional pH Range | 0.0–14.0 pH |
| Optional pH Resolution | 0.1 pH |
| Optional pH Accuracy | ±0.1 pH at 25°C (77°F) |
| Probe Electrode | Platinum spiral |
| Probe Junction | Ceramic diaphragm, double-junction |
| Probe Connection | Standard BNC |
| Probe Cable Length | 2 m / 6.6 ft |
| Power | 2 × AAA alkaline batteries |
| Operating Solution Temperature | 0–50°C / 32–122°F |
| Display | Backlit digital display |
| Auto-Off Function | Yes |
| Meter Warranty | 5-year limited manufacturer warranty |
| ORP Probe Warranty | 6-month limited manufacturer warranty |
Optional pH measurements require a compatible Bluelab pH Probe, sold separately.
How to Use & Probe Care
Taking ORP Measurements
- Prepare the meter and probe according to the manufacturer instructions.
- Remove the probe storage cap.
- Immerse the sensing end of the probe in the water or solution being tested.
- Allow the reading to stabilize and record the ORP value in millivolts.
- Clean and store the probe according to Bluelab's recommended procedure.
Probe Maintenance
Keep the ORP Probe clean and properly hydrated according to Bluelab's guidance. Regular maintenance helps prevent buildup on the sensing components and supports consistent measurement performance.
Storage
Use the supplied storage cap and appropriate KCl Storage Solution as directed in the product manual. Avoid allowing the probe to dry out.
Optional pH Measurement
The meter can also be used with a compatible Bluelab pH Probe. The pH Probe is purchased separately and requires the appropriate pH calibration and maintenance procedures.
Product Manual & Documentation
Download the official Bluelab ORP Meter User Manual for operating instructions, probe maintenance, measurement guidance, storage, and troubleshooting.
View Bluelab ORP Meter Manual (PDF)What's Included in the Box
- 1 × Bluelab ORP Meter
- 1 × Bluelab ORP Probe with Storage Cap
- 1 × Bluelab KCl Storage Solution Sachet — 18 ml / 0.6 fl oz