Reliable Guided Wave Radar Level Measurement
The Honeywell SmartLine SLG 700 is a guided wave radar level transmitter designed for continuous measurement of liquids in process tanks, storage tanks, separators, distillation columns and other industrial vessels.
Using Time Domain Reflectometry (TDR), the radar signal travels along the probe and detects the change in dielectric properties at the product surface. This makes the measurement less sensitive to changes in conductivity, density, pressure and temperature than several conventional level technologies.
Level and Interface Measurement in One Device
SLG 700 can measure liquid level, volume and liquid interface. It can also measure level and interface simultaneously, making it suitable for applications where two immiscible liquids need to be monitored within the same vessel.
The transmitter can measure media with a dielectric constant of 1.4 or greater, depending on the application and probe configuration.
Flexible Probe Configurations
Different process vessels require different probe designs. SmartLine SLG 700 supports:
- Coaxial probes
- Rod probes
- Wire probes
This flexibility allows the transmitter to be adapted to tanks, silos and different installation arrangements, including flanged, threaded, NPT, BSP and bypass/bridle installations.
Designed for Demanding Process Conditions
SmartLine SLG 700 is available for applications with demanding temperature and pressure conditions.
- Measuring range: up to 50 m (164 ft)
- FEP probe range: up to 35 m (115 ft)
- Process temperature: -60 to +450 °C
- Process pressure: -1 to 400 bar
- Repeatability: ±1 mm
- Accuracy: ±3 mm or ±0.03% of measured distance, whichever is greater
For specific configurations, SLG720 is rated up to 40 bar, while SLG726 can reach up to 400 bar.
Easier Installation and Configuration
One practical advantage of the SmartLine level transmitter is that it is designed to reduce commissioning effort. Honeywell states that the transmitter does not require calibration or commissioning upon installation when properly configured for the application.
Configuration can be performed locally through the 3-button keypad or remotely using a handheld configurator and DTM-based field service tools. The advanced graphical LCD provides a multilingual local interface.
Integration with Plant Control Systems
SmartLine SLG 700 is designed for integration with industrial control systems, including Honeywell Experion PKS. Integration can provide additional diagnostics, maintenance status information and transmitter messaging.
Depending on configuration, the transmitter supports HART or Foundation Fieldbus communication and operates from 14–42 VDC for HART or 9–32 VDC for Fieldbus.
Typical Applications
SmartLine Guided Wave Radar Level Transmitters can be used for:
- Process and storage tanks
- Blending tanks
- Distillation columns
- Separators
- Liquid interface measurement
- Inventory measurement
- High-temperature process vessels
- Applications where capacitance, hydrostatic or ultrasonic level measurement may be affected by changing process conditions
The probe signal is guided along the probe, making the measurement less affected by the angle of repose of granular material than some non-contact measurement methods.
Key Features
- Guided Wave Radar (GWR) measurement using TDR technology
- Level, volume and interface measurement
- Up to 50 m measuring range
- Up to ±1 mm repeatability
- ±3 mm or ±0.03% accuracy
- Coax, rod and wire probe options
- Process temperature from -60 to +450 °C
- Process pressure up to 400 bar, depending on configuration
- Advanced graphical LCD with local configuration
- HART and Foundation Fieldbus options
- IP66/IP67 and NEMA 4X enclosure options
- ATEX, IECEx, FM and other hazardous-area approvals available
- SIL 2/3 configurations certified to IEC 61508
FAQ
What is the Honeywell SmartLine SLG 700 used for?
It is a guided wave radar level transmitter for continuous measurement of liquid level, volume and interface in industrial tanks and process vessels.
Can SLG 700 measure liquid interface?
Yes. The transmitter can measure liquid interface and can measure level and interface simultaneously when the application and probe configuration are suitable.
What is the maximum measuring range?
The maximum measuring range is 50 m (164 ft). FEP probe configurations have a maximum range of 35 m (115 ft).
What probe types are available?
SmartLine SLG 700 supports coaxial, rod and wire probes, allowing the transmitter to be selected according to tank geometry, process conditions and installation requirements.
Is guided wave radar affected by changes in conductivity or density?
Honeywell states that SmartLine guided wave radar is less affected by changes in conductivity, density, pressure and temperature than technologies such as capacitance and hydrostatic level measurement. The actual application suitability still depends on the process medium and probe configuration.
What process temperature can it handle?
The specified process temperature range is -60 to +450 °C, depending on the selected configuration.
Can it be used in high-pressure applications?
Yes. The SLG 700 family includes configurations rated up to 400 bar (5800 psi). The actual pressure rating depends on the model and process connection; SLG720 is rated up to 40 bar, while SLG726 can reach 400 bar.
Does SLG 700 require calibration after installation?
Honeywell states that the transmitter does not require calibration or commissioning upon installation when correctly selected and configured for the application. Proper probe selection and application validation remain important for reliable measurement.
What is the difference between guided wave radar and ultrasonic level measurement?
Guided wave radar sends the measurement signal along a physical probe, while ultrasonic level measurement uses a sound wave traveling through the vessel atmosphere. Guided wave radar can therefore be advantageous where changes in gas conditions or vessel geometry make non-contact measurement more difficult.
Is SLG 700 suitable for hazardous areas?
Yes. Depending on the selected configuration, the SmartLine SLG 700 family offers certifications and approvals including ATEX, IECEx, FM, CSA and other regional approvals, as well as SIL-certified configurations.
