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DATASHEET
Digital Microwave Tank Gauge

8900d Digital Radar

APPLICATION • 8900d digital radar is designed for use in custody transfer tank gauging
applications and exceeds the requirements of UK weights and measures
standards for tank gauging. With OIML R85 Certification

FEATURES AND BENEFITS • 0.5 mm level accuracy FMCW range measurement with reference to
SIRA Test Certificate No: Sira 58D20905ALab
• DSP data extraction via dual FFT algorithm
• Graphical Display Panel
• Integrated temperature probe interface 0.1C
• Water level and density inputs
• Optional integrated graphical display
• Optional Tank-side Remote Display
• 4-wire combined power and communications cabling
• Compatible with MTG Diamond Tank Gauging System and other Host
Systems
• Simple commissioning and maintenance through Diamond diagnostic
interface
• Antenna options for fixed roof and stillpipe applications
• Gas tight process connection rated to 40 bar.
MTG’s Patented Hybrid Cavity Backed Spiral
Antenna for stillwell applications where rust or • MTG’s Patented Hybrid Cavity Backed Spiral Antenna® launches the
product build-up is a factor. microwave into low loss TE-01 circular transmission mode eliminating
negative effect of rust or product build-up inside a stillwell.

MEASURING PRINCIPLE 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
Returned
difference frequency is directly proportional to the distance from the target.
Signal Stre
ngth

8900d uses a dual FFT algorithm together with peak tracking to ensure that the
R liquid level is correctly identified and processed.
E
The gauge is known as a ‘digital radar’ due to
• the digital techniques employed to generate the highly accurate linear
L frequency sweep within the synthesized pulse and
Increasing
Range
• the high order digital signal processing using to analyse the return signal
which and which delivers the resulting ‘picture’ of the tank and its
contents.
8900d Digital Radar

SPECIFICATION
GENERAL DESCRIPTION High Accuracy Microwave Tank Gauge –
Non-intrusive FMCW radar level detection with auxiliary inputs
for temperature, density and water interface

APPLICATION Custody Transfer / Inventory Management

Problematic Petrochemicals

PERFORMANCE Level Accuracy ± 0.5mm Ref: OIML R85

Level Measuring Range 0-40 Metres
Temperature Accuracy ± 0.1oC (from Spot/Multiple Averaging/Multiple Spot
Probe)
Temperature Measuring Range -50oC to +200oC

ELECTRICAL Electrical Safety

II 1/2G Ex d [ia] IIB T4 (tamb = -40°C to +65°C)
Power Supply 15-24Vdc
88-264 Vac 47-64 Hz
Power Consumption Less than 12 Watts
Microwave Emissions Less than 0.1m W/cm2
Lightning Protection Full Galvanic and Optical Isolation to 5kA

COMMUNICATION & CONTROL SYSTEMS Host communications Electrical Interfaces:

RS485 2-wire half duplex
4-20mA
4-20mA Wireless
Protocols:
Modbus RTU, MTG proprietary, HART®, ENRAF
GPU®, ENRAF BPM®, SAAB TRL/2®
Alarm Outputs 4 off Digital Outputs
Auxiliary Inputs 4 Inputs, each with the following option
• Discrete, un-isolated
• Discrete, optically isolated
• Analogue, 4-20mA
Temperature Max 22 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 (intrinsically safe)

PHYSICAL Exterior Protection Standard: Aluminium LM25

Option: Stainless Steel AISI 316
Environmental Protection IP67/NEMA 4
Tank Operating Temperature -70oC to +300oC
Working Pressure Up to 40 bar max
Weight 26Kg
Process Connection 2”, 3”, 4”, 6”, 8”, 10”, 12”, 18”, 24” as required
Antenna Sizes Nominal in inches (horn external diameter in mm)
• 2” (50 mm)
• 4” (98 mm)
• 6” (147 mm)
• 8” (194 mm)
• 10” (250 mm)
• 12” (305 mm)
• Parabolic Antenna (425 mm)

Motherwell Tank Gauging

St Michaels Road
Lea Green Ind Est
St Helens
Merseyside
England WA9 4WZ

Tel : + 44 (0) 1744 815211

Fax : +44 (0) 1744 814497

sales@mtguk.com
www.motherwelltankgauging.com

Product Information www.motherwelltankgauging.com Page 2 of 3

 8900d Digital Radar

ORDERING CODE
Approval
XX Without
XM Ship approval
XT ATEX 1/2G, Ex d [ia Ga] IIB T6 Gb (tamb= -20°C to +45°C)
XH ATEX 1/2G, Ex d [ia Ga] IIB T6 Gb (tamb= -20°C to +75°C)
Process Temperature
S -40°C to +80°C
H -70°C to 200°C
L -200°C to +80°C
Process Pressure
SP Standard
HP High Pressure
Process Fitting
FA ANSI Flange
FD DN Flange
Process Size
2 2”
4 4”
6 6”
8 8”
10 10”
12 12”
20 20” * Parabolic Antenna
Process Rating
15 150lb
30 300lb
Tank Process Type
FS Free space
SW Stillwell
PB Parabolic
Power
AC 110-250VAC
DC 24VDC
Communication-Protocol
MT MTG RS485
MB Modbus RS485
AG 4-20mA Analogue
HT 4-20mA HART
EG Enraf GPU (RS485)®
EB Enraf BPM®
ST SAAB TRL/2®
Custody Transfer
XX Without
OI OIML R85
Functional Safety
XX Without
XS SIL
Local Display
XX Without
DI Integral
Remote Display
XX Without
RD With
Additional Measurement
XX Without
T Product Temperature
W Water/Interface Level
D Density/Pressure
V Vapour Pressure
Housing
AL Aluminium
SS Stainless Steel
Coating
XX Without
EP Epoxy
PT PTFE

89

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