Product Short Description
Product Introduction
The LB444 is the core signal processing unit for Berthold non-contact gamma radiometric measuring systems, used to calculate liquid density, slurry concentration, bulk solid mass flow without physical contact with measured media. It receives pulse signals from scintillation gamma detectors mounted externally on pipelines/vessels, processes radiation attenuation data via microprocessor algorithms and outputs standardized analog/digital measurement signals to PLC or SCADA control systems.
Description
Technical & Performance Specifications
- Power Supply Options
- Dual configurable input: 24 VDC industrial control power or 115/230 VAC mains supply
- Power Consumption: Maximum 18 VA operating power
- Measurement Performance
- Full-Scale Measurement Accuracy: < 1% FS under standard process conditions
- Internal Automatic Drift Compensation: Temperature and detector aging gain correction
- Automatic Plateau Check function for scintillation detector performance calibration
- Measurable Medium Range: Liquids, suspensions, pulp slurries, granular bulk solids
- Signal I/O Interfaces
- Input: Pulse signal from NaI(Tl) scintillation counter radiation detector
- Analog Output: Isolated 4–20 mA standard process current signal proportional to density/concentration
- Digital Communication: RS485 Modbus RTU for remote data reading and parameter configuration
- Relay Alarm Outputs: 2 programmable Form-C relay contacts for high/low concentration fault alerts
- Pt100 temperature sensor input for media temperature compensation
- Physical & Environmental Ratings
- Mounting Method: Standard 35 mm DIN rail cabinet mounting or front panel cutout installation
- Protection Class: IP54 sealed front panel housing
- Operating Temperature Range: -20°C ~ +60°C ambient cabinet temperature
- Storage Temperature: -40°C ~ +70°C
- Relative Humidity: 5–95% non-condensing
- Display & Operation
- Multi-line LCD local display showing real-time density/concentration values and fault codes
- Front panel membrane soft keys for on-site calibration and parameter setup
Function Features
- Fully non-invasive measurement system: detector and radioactive source mount externally to pipe, no pipeline cutting or media contact required
- Microprocessor-based digital signal filtering to eliminate process flow turbulence measurement noise
- Built-in automatic plateau test to verify scintillation crystal and photomultiplier tube operating status
- Real-time temperature compensation via Pt100 input to correct density reading deviation caused by media temperature changes
- Configurable high/low limit alarm relays for automatic process interlock control
- Modbus RTU digital communication for remote monitoring, calibration and data logging via factory SCADA
- Long-term stability algorithm offsets photomultiplier tube signal drift from aging and ambient temperature fluctuation
- Fault self-diagnosis covering detector disconnection, cable breakage, radiation source shielding abnormality
- Supports multiple measuring path configurations (30°/45°/90° pipe mounting angles, S/U-shaped pipeline measurement loops)
Working Principle
A sealed gamma radiation source emits constant-intensity gamma rays passing through the pipeline and measured media. Media density directly attenuates gamma radiation intensity; a scintillation detector on the opposite pipeline wall converts residual gamma photons into light flashes inside thallium-doped sodium iodide crystals. A photomultiplier tube amplifies light signals into electrical pulse trains transmitted to the LB444 unit. The internal microprocessor calculates real-time density/concentration by comparing received pulse count rate against factory-calibrated reference curves, applies temperature and detector drift correction, then outputs standardized 4–20 mA analog signals or Modbus digital data to upper-level control systems. The unit continuously monitors detector pulse stability and triggers alarm relays if measurement deviation exceeds pre-set thresholds.
Material & Structural Composition
- Outer Enclosure: Flame-retardant ABS plastic sealed housing with IP54 silicone rubber front panel gasket
- Internal Circuit Board: Multi-layer FR4 industrial PCB with conformal anti-corrosion coating for damp cabinet environments
- Display Module: Transflective industrial LCD with wide operating temperature liquid crystal
- Terminal Blocks: Nickel-plated copper screw terminals with PA66 flame-retardant insulation
- Mounting Bracket: Galvanized steel DIN rail slide mounting clip
- Internal Shielding: Mu-metal electromagnetic shielding layer to block external industrial drive frequency interference
Installation Requirements
- Install inside sealed industrial control cabinet via standard 35 mm DIN rail; avoid direct exposure to process steam, dust or corrosive gas
- Separate signal wiring (detector/Pt100 cables) from high-power motor drive wiring with minimum 30 cm routing distance
- Detector-to-LB444 signal cable must use dedicated shielded coaxial cable, maximum cable run limited to 100 m
- Connect unit PE ground terminal to facility protective earth grid to eliminate electromagnetic interference
- Complete full calibration procedure after initial installation and every 6 months of continuous operation
- Pt100 temperature sensor must mount in direct media contact for accurate temperature compensation data
- Maintain cabinet ambient temperature between -20°C and +60°C; install cooling fans for high-temperature process plant environments
Application Scenarios
- Mining slurry concentration measurement for mineral flotation processing
- Paper mill pulp density monitoring in pulp transport pipelines
- Wastewater treatment sludge solid content continuous measurement
- Chemical plant liquid product density control in mixing and blending pipelines
- Food & beverage production syrup concentration monitoring
- Dredging pipeline sediment mass flow and solids concentration measurement
Usage Precautions
- Do not open sealed front housing during live operation; internal high-voltage photomultiplier power circuits present shock hazard
- Radiation source handling, installation and maintenance must comply with national radioactive material safety regulations
- Signal cable shielding must connect to unit PE terminal at one end only to avoid ground loop measurement noise
- Avoid mounting LB444 near large variable-frequency drives or welding equipment generating strong electromagnetic fields
- Perform automatic plateau calibration after detector replacement or long-term system shutdown
- Regularly inspect LCD display gasket seal to prevent moisture ingress causing internal PCB corrosion
- Relay alarm output circuits require external fusing to protect internal contact switches from overload damage
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