KongsbergK-Gauge TOP KONGSBERG Tank Overfill Protection System

K-Gauge TOP 

KONGSBERG Tank Overfill Protection System

Features

• No moving parts 

• Continuous verification - AutroCAL®

• Configurable alarm limits 

• Closed level gauge suitable for all tank 

designs 

• Utilize 50 mm still pipe 

• Modular design 

• Intrinsically safe for use in all zones 

General description 

The KONGSBERG radar based Tank Overfill 

Protection System for gas carriers meets the IMO 

requirements ‘Cargo Tank Overfill Protections 

System’. 

The system includes radar tank gauges, 

processing and alarm handling units, and a 

dedicated operator panel. Integration to K-Gauge 

level gauging system is included with mimic 

presentation on the Operator Stations. 

All equipment on deck is designed for rugged 

marine environment and manufactured in AISI 

316L stainless steel. Accurate measurement is 

possible regardless of the tank atmospheric 

conditions. Flexible hardware and software 

modules ensure easy adaptation to Liquefied 

Petroleum Gases (Propane, Butane), Ethylene, 

Ammonia (NH3), and Liquefied Natural Gas. 

Principle of operation 

The RTG emits a frequency sweeping 

microwave signal through a still pipe. The 

distance is derived from the time delay of the 

reflected signal. 

The still pipe is assembled by one top-, middleand bottom section. Total length of the still pipe 

is typically 10 meter, and the system allows for 

several adjustable alarm limits in the area of the 

middle section (6 meter). 

The pipes have ventilation holes allowing the 

vapour pressure inside and outside the pipe to 

stabilize, thus allowing the liquid to rise or fall 

unimpeded in the pipe. 

Each pipe section is supplied with flanges 

prepared with reference markers. The liquid level 

and the markers are measured simultaneously, so 

the system automatically verifies itself at every 

measurement. By careful calibration of the pipe 

sections length before installation, the positions 

of the markers are recorded and stored in the 

system. By comparing the liquid echo with the 

reference marker echo, a continuous autocalibration of the level gauge is done. 

The electronic unit in the RTG includes a 

patented signal detection method that ensures 

optimum performance. Combined with its superb 

signal-to-noise ration, GLA-310/5TOP offers the 

highest measurement reliability and accuracy. 

Each RTG is connected to a dedicated signal 

processing unit, where the AutroCAL® principle 

is employed. 

AutroCAL® 

AutroCAL® is a unique calibration and 

verification function in the KONGSBERG 

system. Gas vapor density and mixture of gases 

influence the propagation speed of the radar 

signal, thus the accuracy of the measurement. 

By using pipe joint reference markers, 

AutroCAL® continuously compensates for the 

changes caused by the differences in the 

propagation speed. 

With AutroCAL®, the influence of the gas vapor 

density and composition is measured and 

compensated for automatically. 

Building blocks

The K-Gauge TOP system consists of the 

following hardware units: 

• Radar Tank Gauge: GLA-310/5TOP (1 ea tank) 

• Radar Processing Unit: GLK-300/x (1 ea tank) 

• Remote Controller Unit: RCU502 

• Relay output unit: RDIOR420 

• Operator/Alarm Panel 

• Interface to K-Gauge Operator Station

Radar Tank Gauge GLA-310/5 

Measuring range: 0 to 10 meter (increased measuring ranges on request) 

RTG RMS accuracy: 2 mm 

System RMS accuracy: 5 mm 

Ex classification: 

Ex certification:

Ex ia IIC T4 

09ATEX1330X 

Frequency: X-band (10 GHz) 

Materials: AISI 316(L) in housing and connection box 

PTFE/PEEK antenna lense facing the cargo 

AISI 316(L) or Al alloy 5083 in still pipe 

Protection: 

Weight: 

Cable size: 

IP 66/67 

10.7 kg 

Ø12-Ø20 mm 

Environmental temperature: -45 °C to +85 °C 

Tank temperature: 

Tank pressure 

Down to -165 °C 

Up to 10 bar g 

TOP processing system 

Power supply voltage: 24 VDC ±20 % 

Operating temperature: 0 °C to +70 °C 

Operating humidity: 95 %, non-condensing 

Quality standard: ISO 9001 

Generic EMC standard: Emission: IEC 60945 / Immunity: IEC 61000-4