Overview
The ELIT-ORP-33C is the refillable glass body variant of the ELIT ORP combination electrode range, designed for precision ORP measurements in laboratory, field, and light industrial environments where the electrode is not submerged or operated under pressure. Its wide-ring liquid junction and refillable design enable reduced liquid junction potential and extended electrode life, making it the preferred choice where measurement accuracy is paramount.
Model selection: ORP-31C = general applications, plastic body,
platinum rod. ORP-32C = demanding applications, plastic body, platinum ring.
ORP-33C = precision applications, refillable glass body, wide ring junction.
Specifications
| Parameter | Value |
|---|---|
| Body Dimensions | 12 × 120 mm |
| Body Material | Glass, refillable |
| Junction Type | Wide ring liquid junction |
| Sensing Element | Platinum |
| Reference System | Ag/AgCl in saturated KCl |
| Reference Offset | ~200 mV vs Standard Hydrogen Electrode Eh = Emeasured + ≈200 mV |
| Cable / Connector | 1 m (optional 3 m), BNC |
| Temperature Range | 0 °C to 80 °C |
| Protective Skirt | Yes |
| Temperature Compensation | None (ORP measurements are temperature-dependent) |
Applications
Aquaria
Aquaculture
Swimming Pools
Ponds
Water Quality
Disinfection
Corrosion Measurement
Cooling Towers
Pollution Control
Pulp Bleaching
Wastewater Treatment
Price: exc. VAT ·
Order at elyxir.co.uk/products/sensors
For continuous real-time monitoring, explore ELIT analysers and monitors at elyxir.co.uk/products
For continuous real-time monitoring, explore ELIT analysers and monitors at elyxir.co.uk/products
Preparation & Operating Instructions
- Remove the protective storage bottle and keep it for future storage.
- Refillable junction preparation: Remove the covering Parafilm from the refill stopper and open the stopper temporarily to allow the reference electrolyte to flow freely to the junction.
- Rinse any salt deposits from the electrode tip with distilled water.
- Connect the BNC connector to your meter or analyser.
- Allow a short stabilisation period before recording measurements.
ORP measurements are temperature-dependent. No automatic temperature
compensation is available — record sample temperature alongside readings
where accuracy is critical.
Understanding ORP Values
ORP (Oxidation-Reduction Potential) indicates the oxidising or reducing capacity of a solution. A higher reading indicates more oxidising agents present.
| Application | Typical ORP Range |
|---|---|
| Freshwater aquarium | 250–300 mV |
| Saltwater aquarium | 350–400 mV |
| Aquarium — harmful for fish | > 400 mV |
| Pond — good water quality | ~300 mV |
| Pond — decomposing organics | < 150 mV |
| Pond — chlorine / cleaning agents | > 450 mV |
| Swimming pool (ideal, pH 7.2) | ≥ 700 mV |
Maintenance & Storage
- Storage: Keep the electrode in the protective storage bottle filled with saturated KCl solution when not in use. During storage, seal the refill stopper with Parafilm to prevent evaporation of the reference electrolyte.
- Refilling: When the reference electrolyte level drops, refill through the stopper with fresh saturated KCl solution.
-
Cleaning:
- Non-organic contamination: soak in 0.1 M HCl for 10 minutes.
- Organic / oily contamination: soak in 1:10 diluted detergent for 10 minutes.
- After any chemical cleaning: re-soak in saturated KCl for 3 hours.
- Reference clogging: The Ag/AgCl reference may become clogged when used in samples containing TRIS buffer, proteins, or sulfides.
Glass body — handle with care. Avoid mechanical shock. Do not
use with samples that attack glass (e.g. hydrofluoric acid solutions).
Performance Verification
| Test Solution | Expected Response |
|---|---|
| pH 7 buffer + Quinhydrone | 86 ± 15 mV |
| pH 4 buffer + Quinhydrone | 263 ± 15 mV |
| ZoBell's solution (25 °C) | 238 mV |