Level Indicator | Automatic
Tank Gauges | Servo
NT 5000 Systems
8900d High Accuracy Radar Tank Gauge
Control Systems Limited 8900d High Accuracy Radar Tank Gauge is
a non-intrusive FMCW (Frequency Modulated Continuous Wave) radar
tank gauge which uses a combination of the latest digital technology
and unique signal processing to provide level measurement accurate
to ±1mm. The unit optionally provides temperature (averaging / spot),
average density, water interface measurement and hardware and software
use in Custody Transfer and inventory management Applications including
problematic petrochemicals and products stored at temperature and
The 8900d is
the latest generation of level gauges manufactured by Motherwell
Control Systems and is a non-contact high accuracy tank gauge with
no moving parts working on the principle of radar.
of the 8900d is very modular in nature allowing for a wide range
of options such as different flange sizes and adapters to suit a
wide range of process connections.
and unique signal processing are used and means that there is no
reference coil as is the case with analogue radar gauges and the
gauge is thus not susceptible to temperature and pressure extremes.
within the gauge are modular in nature, based on a card frame system
complete with watchdog feature, which warns of any part of the system
The 8900d is
a complete tank gauging system located at the top of the tank and
readily accepts signals from additional tank sensors to provide
temperature, pressure and water interface information. For example,
connecting the 8900d to the MCS 3791 series temperature probes provides
measurement of both product and vapour temperature together with
water interface measurement.
product level measurement – accurate to ±1mm.
referencing through tank mapping software
to four level alarm contacts
measurement accurate to *0.1 degrees C
Single Spot, Multiple Spot or averaging Temperature Probes
elements of Multiple and Averaging Probes are read continuously
profiling illustrates thermal product stratification and
provides vapour temperature measurement.
measurement is achieved by measuring the time of flight for a radio
wave to travel from the radar gauge to the liquid surface and back
The 8900d Radar
Gauge uses the frequency modulated continuous wave (FMCW) microwave
radar principle, operating at an average frequency of approx. 10
A high stability
radio frequency is generated within the gauge, whose frequency is
linearly ramped between 9.5 and 10.5 GHz, which is then fed to a
dieletric rod antenna from which it is launched into free space.
In normal operation
the gauge is mounted at the top of the storage tank with its antenna
pointing down towards the surface of the product inside.
The radio wave
signal is emitted from the rod antenna and radiates outwards ‘seeing’
all the tank internals. The reflected radio wave is then collected
by the same antenna and the gauge compares the difference in frequency
between the outward and return radio waves.
difference is proportional to the distance travelled.
frequency difference then undergoes a number of processes including
Fourier Transform techniques and peak location algorithms which
are then used to digitally locate the peak frequency corresponding
to the product level reflection from which the liquid level is then
calculated and displayed on a liquid crystal display inside the
Free – There are no moving parts within the gauge and thus
no problems associated with mechanical wear and tear.
Technology – suitable for difficult products such as bitumens
Power Requirements – Both power and communications can be
safely distributed via one 4-wire cable running around the
tank farm in multidrop format.
of Installation Options – wide range of installation options
on most types of storage tank design including that storing
product at temperature and pressure extremes. The radar
works in both stilling pipes and free tank space and can
be installed in conjunction with high pressure isolating
valves dependent on valve size.
Design – Both the gauge body and internals are modular in
nature resulting in greater flexibility to suit a wide range
of process connections and different antenna as required.
Rod Antenna – the standard narrow rod antenna produces a
broad beam and is easy to install with further advantages
either inside or outside of the tank (longer adaptor
of Installation, as the antenna is not directionally
surface resists surface coating build up and offers
a degree of self cleaning – liquid runs off.
Protection – through galvanic and optical isolation.
The 8900d High
Accuracy Radar Tank Gauge is fully compatible with the full range
of MCS Tank Gauging Systems, including MCS Series 5000 Inventory