Critical Technical Advantages
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High-Density Multi-Point Sensing: The NMT81 can be equipped with up to 24 Resistance Temperature Detectors (RTDs) distributed along its length. This high density allows for a highly accurate temperature profile of the product, regardless of thermal stratification within the tank.
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Custody Transfer Precision: With a total accuracy of ± 0.032°C (following a 5-point calibration), the NMT81 meets the stringent requirements of international weights and measures standards. This precision ensures that financial transactions based on tank inventory are fair and documented.
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Integrated Water Bottom Detection: An optional 2-meter capacitance sensor can be integrated into the bottom of the probe. This allows for the continuous, real-time measurement of the water level that naturally accumulates under oil or chemicals, ensuring pure product volume can be calculated accurately.
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System Synergy: The NMT81 is designed to work seamlessly with the Proservo (NMS8x) and Micropilot (NMR8x) series via the TankSideMonitor NRF81. It functions as a primary data source for advanced tank gauging systems, providing the temperature compensation necessary for radar or servo-based level devices.
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Operational Reliability: The device employs a software algorithm to process redundant RTDs. If one sensor element fails, the system automatically compensates, significantly reducing maintenance-related downtime and ensuring the “average” calculation remains valid.
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Corrosion Resistance and Protection: All process-wetted parts are built to resist corrosion from hydrocarbons and chemicals. The housing is both waterproof and dustproof, designed for long-term exposure on top of external floating or fixed-roof tanks.
Technical Performance Matrix
| Feature | Details |
| Primary Function | Multi-point average temperature & water level |
| Total System Accuracy | ± 0.032°C (± 0.06°F) |
| Measuring Range | -40 to +60°C (-40 to +140°F) |
| Max. Probe Length | 100 meters (328 ft) |
| Sensor Capacity | Up to 24 RTD elements |
| Water Level Option | 2-meter capacitance sensor |
| Process Connection | Flanges starting from 1-1/4″ |
Primary Applications
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Oil & Gas Custody Transfer: Precise inventory monitoring in refineries and terminals where small temperature errors lead to large financial discrepancies.
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Chemical Storage: Average temperature measurement in large-scale chemical tanks to ensure product stability and accurate inventory.
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Inventory Management: Providing real-time data for Tank Farm Management systems to monitor net standard volume (NSV).
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Water Interface Detection: Continuously tracking the water bottom in crude oil tanks to manage drainage and prevent pump contamination.
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Thermal Stratification Analysis: Identifying temperature layers in stored liquids to optimize heating or mixing processes.




