Using the SMART WIO water-in oil sensor in oil condition monitoring systems, ensures optimal engine performance while protecting against potential damage caused by excess water content.
The SMART WiO (Water-In-Oil) Sensor measures the absolute water content in oil—not the free water or emulsion that is detectable by standard water in oil test kits. This advanced oil condition sensor utilises a capacitive measurement technique that operates on the principle of water absorption in oil, providing a physical measured value expressed as % Humidity.
New oil can hold a specific amount of dissolved water, known as the “saturation point.” If this limit is exceeded, free water may separate, potentially causing corrosion within the engine. The saturation point is influenced by temperature and other factors such as the type of oil (mineral or synthetic) and additive formulations, and can change throughout the oil’s lifecycle.
The PAV (Pre Alarm Value) is calibrated to 50% humidity, while the MAV (Main Alarm Value) is set at 90% humidity. Should humidity exceed 100%, it indicates the presence of free water. If the WiO Water-in-oil Sensor raises an alert, indicating humidity above 90%, it signals potential damage as conditions approach the saturation point.
Water in Oil Sensor Application
Oil condition monitoring system for lubrication oils including:
- 2 and 4 Stroke Engines
- Compressors
- Pumps
- Gearboxes
- Turbines
Condition monitoring for hydraulic oils including all machines using hydraulic oil up to 10 bar
Water in Oil Sensor Features
The WIO Water-in-oil sensor
- Accurately measures the absolute water content in oil.
- Provides early warnings via pre-alarm and alarm features.
- PAV (Pre Alarm Value) set to 50% humidity; MAV (Main Alarm Value) set to 90%.
- Considers oil temperature for saturation measurements.
- Is independent of oil type and age for reliable monitoring.
- Requires no cleaning of the sensor.
SMART WiO – Water in Oil Sensor Type
Water in Oil Sensor Specification
| MEASUREMENT | |
| Power Supply | 18…32 VDC |
| Current Consumption | 60mA |
| Polarity Protection | Yes |
| Alarm relays | Pre-alarm at 50% humidity Main alarm at 90% humidity |
| Output Current | <300mA |
| Operating Temperature | -25 to +85 0C |
| Protection Degree | IP67 |
| Analog Output: Water in Oil | 4…20 mA (equiv. 0…100% Humidity Linear) |
| Analog Output: Temperature | 4…20 mA (equiv. 0…1000C Linear) |
| Dimensions: | 125mm x 80mm x 57mm |
| Local Indication | LED Indicators |
| Sensor Probe Specification | |
| Wrong Polarity Protection | Yes |
| Operating temperature | -25 to 85 deg C |
| Protection degree | IP65 |
| Pressure resistance against medium | 10 bar |
| Connection type | G3/4” Male Thread |
| Material | Stainless Steel AISI 303; 1.4305 |
| Dimensions | 50mm x 187mm |
| Cable Length to Controller | 15m |
| Insertion Length | 120mm |
| Local indication | LED Indicators |
| Options | |||
| Indicator Dial Temperature | Indicator Dial Humidity | ||
| Indicator Dial type | Analog needle type | Indicator Dial type | Analog needle type |
| Unit of Measurement | Degrees Celsius | Unit of Measurement | % Humidity |
| Range | 0 – 1000C | Range | 0% – 100% Humidity |
| Dimensions | 96mm x 96mm x 77mm | Dimensions | 96mm x 96mm x 77mm |
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