High-Precision Radar for Tank Gauging
The Endress+Hauser Micropilot NMR81 is designed for applications where level measurement is closely tied to inventory accuracy and custody transfer requirements. Using 80 GHz radar technology, it provides measurement accuracy of up to ±0.5 mm and a maximum measuring distance of 70 m.
This makes the NMR81 particularly suitable for large storage tanks where reliable and repeatable level information is important for day-to-day inventory management and measurement control.
Focused 80 GHz Radar Measurement
The NMR81 uses a drip-off lens antenna with an 80 GHz transmitting frequency and a narrow 3° beam angle. The focused radar beam helps reduce interference from nearby tank walls and other obstacles, which is especially useful when the tank nozzle is positioned close to the wall.
The design gives the instrument a clear advantage in free-space tank applications where installation conditions can make radar measurement more demanding.
Designed for Custody Transfer Applications
The NMR81 is developed specifically for custody transfer and inventory control applications. Endress+Hauser lists compliance with OIML R85 and API MPMS, together with metrological approvals including OIML, NMi and PTB.
For tank farms and other applications where measured inventory has commercial significance, these approvals are an important part of the instrument's overall value.
Long Measuring Distance for Large Tanks
With a maximum measuring distance of 70 m, the NMR81 is suitable for large storage tanks and free-space level measurement applications. For applications involving calibration to regulatory standards, the specified maximum measuring distance is 50 m.
Key measurement specifications include:
- Accuracy: up to ±0.5 mm
- Maximum measuring distance: 70 m
- Regulatory calibration range: up to 50 m
- Radar frequency: 80 GHz
- Process pressure: vacuum to 16 bar
- Process temperature: -40 to +200°C
Built for Industrial Tank Environments
The NMR81 uses 316L and PTFE for its main wetted parts and is available with flange-based process connections. Depending on the configuration, flange sizes range from DN50 / 2" to DN300 / 12", with alignment-tool and UNI-Flange options available for selected sizes.
Its industrial design also supports applications requiring international explosion protection and safety approvals.
Flexible Integration with Tank Gauging Systems
The NMR81 can integrate with plant and tank management systems through several communication options. Depending on configuration, available outputs include Modbus RS485, V1, WM550, HART, BPM and TRL/2, as well as 4–20 mA and relay outputs.
This gives the instrument flexibility when replacing existing tank gauging equipment or integrating it into established DCS and inventory systems.
Key Features
- 80 GHz radar technology with focused 3° beam angle
- Accuracy up to ±0.5 mm
- Maximum measuring distance up to 70 m
- Designed for custody transfer and inventory control
- Supports OIML R85 and API MPMS requirements
- OIML, NMi and PTB metrological approvals
- Flange process connections from DN50 / 2" to DN300 / 12"
- Process pressure from vacuum to 16 bar
- Process temperature up to -40 to +200°C
- 316L and PTFE main wetted parts
- Multiple communication options including Modbus RS485, HART, V1 and WM550
- International explosion protection options
- WHG overfill protection and SIL options
Typical Applications
Tank Farms & Storage Terminals
High-accuracy radar measurement for large storage tanks where reliable inventory information is required.
Custody Transfer
Suitable for applications where level measurement contributes to commercially relevant quantity measurement and requires recognized metrological approvals.
Inventory Control
Provides continuous level information for monitoring stored liquids and managing tank inventory.
Large Storage Tanks
The 70 m maximum measuring distance and focused 80 GHz beam make the NMR81 suitable for large free-space tank applications.
Tank Gauging Systems
Designed for integration with established tank gauging and plant control systems through multiple communication interfaces.
FAQ
What is the Endress+Hauser Micropilot NMR81 used for?
The NMR81 is primarily designed for custody transfer and inventory control, particularly in large storage tanks and tank gauging applications.
How accurate is the Micropilot NMR81?
The NMR81 offers accuracy of up to ±0.5 mm, depending on the application and configuration.
What is the maximum measuring distance?
The maximum measuring distance is 70 m. For calibration to regulatory standards, Endress+Hauser specifies a maximum distance of 50 m.
Why does the NMR81 use 80 GHz radar?
The 80 GHz frequency allows the NMR81 to use a focused 3° beam angle, helping reduce interference from tank walls and nearby obstacles. This is particularly useful when the tank nozzle is positioned close to the wall.
Is the NMR81 suitable for custody transfer?
Yes. The NMR81 is specifically designed for custody transfer applications and is available with metrological approvals including OIML, NMi and PTB. Endress+Hauser also states that the device meets requirements according to OIML R85 and API MPMS.
What communication interfaces are available?
Depending on the selected configuration, the NMR81 supports communication options including Modbus RS485, V1, WM550, HART, BPM and TRL/2, as well as 4–20 mA and relay outputs.
What process conditions can the NMR81 handle?
The official specifications list a process temperature range of -40 to +200°C and process pressure from vacuum to 16 bar.
