8900d is an ullage-referenced tank contents level measurement device. It measures the range from a reference position inside the gauge to the liquid surface using the FMCW method. The product level is calculated by subtracting the measured range figure from the tank empty range value.
In FMCW, or Frequency Modulated Continuous Wave, radar measurement the emitted radar signal frequency is modulated between two values and the difference between the transmitted signal and the return echo signal is measured. This difference frequency is directly proportional to the distance from the target. In storage tanks there may be many "targets" in addition to the liquid level (eg, pipes, fittings, coils, ladders, weld seams, false echoes from tank roof) and the difference frequency measured may consist of many component frequencies, each frequency representing a target. 8900d uses a dual FFT algorithm together with peak tracking to ensure that the liquid level is correctly identified and processed.
FEATURES
Custody Transfer Tank Gauge
Columnated horn
Horn antenna in Stainless and Hastelloy
±1 mm level accuracy FMCW range measurement
DSP data extraction via dual FFT algorithm
Graphical Display Panel (with view select)
Integrated temperature probe interface ±0.1°C
Water level and density inputs
Optional integrated graphical display
Optional Tankside Remote Display
4-wire combined power and communications cabling
Digital alarm outputs
Fieldbus communications
Pressures to 40 Bar
Fittings from 2" upward
Range 40m
Tank Top Connectivity
8900d provides tank-top interfaces for:
Temperature measurement (average or spot)
Level alarms (discrete outputs)
Water level measurement (separate water probe)
Density measurement (separate density probe)
Tankside Display Unit
With optional expansion I/O provides a gateway for control and monitoring of tankside valves and other discrete devices
Control Room Connectivity
8900d interfaces with host systems via a two-wire field bus which may be
configured in either a star or multi-drop network. As the gauge runs on two-wire 24Vdc it is possible to run the communications and power signals in the same cable. The field bus provides continuous updates of level, temperature and status data for all connected gauges. The entire register map of each gauge is also available for dynamic access during gauge commissioning and for diagnostic purposes.
Specifications:
Level Accuracy: ± 1mm
Level Measuring Range: 0-40 meters
Temperature Accuracy: ± 0.1°C (from Spot/Multiple Averaging/Multiple Spot Probe)
Temperature Measuring Range: -50°C to +200°C
Power Supply: Standard: 15-24Vdc (Options: 110/ 130/ 220/ 240 Vac 50/60 Hz)
Alarm Outputs: 4 off Digital Outputs
Analogue Inputs: 4-20mA Input
Temperature: 20 RTD inputs from Spot/Multiple Averaging/Multiple Spot
Probe, Cu or Pt elements
Integral Display: Illuminated Graphics Display Panel with selectable display
Remote Display unit: Scrolling LCD display (instrinsically safe)
Exterior Protection: Aluminium LM25 / Option: Stainless Steel AISI 316
Environmental Protection: IP67/NEMA 4
Working Pressure: Up to 40 bar max
