A complete range of sensors including liquid level switches, TLA (Tank Level Alarm), temperature and pressure sensors.

Sensors General

The API Marine state-of-the-art range of sensors are designed and built to withstand the harsh environment and heavy conditions in marine applications.

The sensors are designed for precise measurements of level, temperature and pressure in most types of liquid.

All the sensors have a unique design with no electronics or moving parts inside the tank. This results in a longer lifespan with all sensors and transmitters being virtually service-free. Should there however be a need for maintenance – all critical and electronic parts can be accessed from outside the tank.

The majority of the API Marine sensors have “winterization” approval, and are as such ideal for application operating in the harsh arctic environment.


  • TGD™ Tank Gauging Device (Level, Pressure & 3 x Temperature)
  • TGD-R™ Tank Level Radar
  • TGD-L™ Tank Gauging Device (Level)
  • TGD-TP™ Tank Gauging Device (Temperature / Pressure)


  • UTS™ Ultrasonic Tank Switch
  • TLA™ Tank Level Alarm (95% / 98%)


  • UPT™ Universal Pressure Transmitter
  • UTT™ Universal Temperature Transmitter

UTS™ – Ultrasonic Level Switch

Ultrasonic Level Switch UTS™ has extended operating temperature range from –200°C to +450°C and is designed for level detection in cargo holds, wells & service tanks in sea and river ships, oil tankers, chemical tankers, gas carriers, offshore drilling platforms.

Ultrasonic Level Switch UTS™ is made of stainless steel and is used for level detection of liquids in vessel tanks, storage tanks, bilge water tanks, cofferdams as well as for control of water ingress to vessel’s compartments.

The operating principle of UTS™ is based on a breakthrough patented acoustic wave technology, providing outstanding results in extreme operating temperatures. Accuracy of measurement is ensured regardless of shape of tank, type of liquid or liquid temperature

UTS™ is installed outside the tank/pipe with only a metal rod inside the tank/pipe. Acoustic waves in the metal rod created by piezo-electric transducer ensure transmission of signals. When liquid in the tank reaches the probe on the rod, the emission of sound
waves is muffled. This change is picked up by the piezoelectric transducer and a signal is transmitted to the corresponding alarm. Having only the metal rod inside the tank and no mechanical or moving parts means no maintenance is required.

UTS™ can be easily installed in vertical, horizontal or any inclined position and is tested for operation in a wide range of media, such as water, oil, petroleum, petrochemicals, acids, wastewater as well as many others. Made of high-grade stainless steel, UTS™ can also be used in tanks and reservoirs with food products.

UTS™ can be installed indoors as well as outdoors, including explosive environments and harsh arctic conditions.

UTS™ is characterized by high resistance to sticky products, high robustness and shock resistance and increased reliability under dynamic load and vibrations due to reinforced rod and electronic unit of new generation. UTS™ is also supplied in a special “Arctic”
version, for applications in harsh environments with ambient temperature of down to –60°C without heating the device.

API UTS™ Features:

  • Any type of liquid
  • Only steel rod inside the tank (electronics and connections outside)
  • Fully welded construction
  • No moving parts
  • Extended temperature range
  • No maintenance required
  • Automatic self test
  • No calibration needed
  • Explosion proof
  • Pre-adjustable alarm points
  • No sensitivity to foam
  • More than 300 possible variations

TLA™ – Tank Level Alarm

TLA™ – Tank Level Alarm is used for detection of high (95%) and high-high (98%) levels in tanks. TLA™ is installed on the deck of tankers, gas carriers, floating storages, FSO, FPSO, onshore storage tanks for oil, petroleum products and liquefied gases.

Built on the same patented acoustic wave technology as UTS™, TLA™ features high level of accuracy, reliability and customizability.

TLA™ represents a two-point level switch with alarm levels defined by length of rods, which are produced on request. Built-in test buttons are used for performing functionality test before filling in the liquid, in accordance with requirements of classification societies. Being highly adjustable to customer’s requirements, TLA™ can also be supplied as a three-point version.

Scope of supply consists of a flexible metal hose 0.5m for connection to the metal pipe, in which cable routing is laid on the deck.

TLA™ Features:

  • Works with any type of liquid and liquefied gas
  • Easy installation
  • No maintenance
  • No moving parts
  • No electronics inside the tank
  • No sensitivity to vapor, moisture and foam
  • Automatic self test
  • Lengths on request
  • Only steel rod inside the tank (electronics and connections outside)

Tank Level Radar

The API Marine Tank Radar is especially designed for marine applications. The tank radar is a very compact solution with measuring range up to 35 meters. It can be delivered with flange size from DN-100 to DN200, and as such with small on-deck space requirements.

The DN200 will have the option to have a built-in pressure transmitter. The tank radar is very easy to install and service friendly with easy access to main electronics from the main housing without having to access or open the tank. For ease of service and set-up the radar has the possibility for all necessary settings and adjustments through the main electronics. The tank radar provides a standard analogue output of 4-20mA to the control cabinet. The radar also has a built-in view glass which at all times gives the current level in the tanks.

The radar level transmitter antenna emits narrow pulses, which will be transmitted via the antenna. The micro wave will be reflected at the surface of a medium. The reflected wave will be received by the antenna system and fed into the electronic circuit, which automatically turns it into a level signal.

Measuring reference is the bottom surface of threads or the sealing surface of a flange.

Main Advantages:

  • Applicable for oil, product & chemical tankers
  • Non-contact measuring, no wear and tear
  • High accuracy
  • Customized variations
  • Easy installation & maintenance
  • Measuring range 0-35m

TGD™ – Tank Gauging Device (Temperature / Pressure)

TGD-T™ is a high-accuracy multipoint (up to 15 measurement points) temperature sensor, which can be used in almost any type of liquid.

As standard, the TGD-T™ is manufactured in stainless steel with an ingress protection of IP67. It consists of housing with a built-in multiplexer and a flexible temperature probe with up to 15 PT-100 thermometers inside the probe.

The measurement accuracy of the TGD-T™ is 0.15°C when using DIN A class resistance thermometers.

TGD-T™ ensures accurate measurements of average product temperature even when there is a vertical temperature gradient in the tank.

TGD-T™ is ATEX approved and can be directly mounted in hazardous areas. The multipoint solution is easy to install with a minimum of cables. The length of the temperature probe and the layout of the thermometers can be based on customer requirements and request.

Main Advantages:

  • Precise and reliable measurement in any liquids including aggressive media
  • Wide temperature range (from -200 to 850°C)
  • HART® 2-wire connection
  • Less cabling – only 2 wires
  • Up to 15 measurement points
  • Easy installation (flexible probe)
  • Easy maintenance
  • Compact unit
  • Any length on request

TGD™ – Tank Gauging Device (Level/Pressure)

The TGD-L™ level sensor is a non-contact level gauge that has been developed for measuring the level of liquids, slurries and sludge including solvents, acids and caustics, waste chemicals, oils, liquefied natural gas, liquefied petroleum gas, food products and most water based solutions. TGD-L™ uses the patented principle of Guided Low Frequency GLF™ wave propagation, which allows for equally precise measurement accuracy along the tank height for any shape of tank and at nearly any conditions in the tank.

The principle of operation of the TGD-L™ is based on the emission of an impulse acoustic signal to the liquid surface and receiving the signal reflected from the surface. The level in the tank is calculated based on the measured signal transit time to the surface of the liquid and back. The level in the tank is measured by using a number of reference reflectors, located along the height of the tank.

To avoid a negative influence from other acoustic signal reflectors in the tank, the acoustic signal is guided in a steel pipe going all the way down to the bottom of the tank. The tank geometry and objects inside the tank, such as ladders, heating pipes, etc., do not affect the signal. Reference points are located along the pipe.

The level sensor system includes a receiving and emitting unit (antenna), a system of reference reflectors located between the antenna and the liquid’s surface, an electronic unit and a processing unit. The antenna emits an acoustic signal to the surface and receives signals reflected from the liquid surface, as well as the reference reflectors. A processing unit can then calculate the distance to the liquid surface based on the 2-wire output signals enhanced by an amplifier circuit of the electronic unit.

TGD-LP™ is a TGD-L™ level sensor with a pressure sensor installed in the same housing. The pressure sensor is used for measuring the tank pressure in the tank.

The TGD-LP™ with level gauging device and pressure transmitter combined into one sensor has the advantage of only one deck penetration as well as only one cabling form the combined sensor to the control cabinet/system saving both time and installation cost. The sensor can be easily serviced and maintained from the sensor housing without the necessity to the tank.

The sensor can be easily serviced and maintained from the sensor housing without the necessity to access the tank.

Main Advantages:

  • Non-contact level gauge with high accuracy
  • Automatic self-calibration every 2 seconds
  • HART® 2-wire connection
  • Less cabling – only 2 wires
  • Compact unit
  • Customized variations
  • Easy maintenance
  • Wide pressure measurement range -1 to 40 bar
  • Non-contact level gauge with high accuracy
  • Automatic self-calibration every 2 seconds
  • HART® 2-wire connection
  • Less cabling – only 2 wires
  • Compact unit
  • Customized variations
  • Easy maintenance

TGD™ – Tank Gauging Device (Multi-function)

TGD™ (Tank Gauging Device) is a multifunctional deck sensor designed for the simultaneous measurement of level, temperature (up to 15 points), pressure and density (option) in the cargo tanks of tankers, gas carriers, floating storages, FSO, FPSO, offshore drilling and fixed platforms, onshore oil, petroleum products and liquefied gas storage tanks.

Depending on the application type, the TGD™ can be supplied as a 1-channel (level or temperature measurement), 2-channel (level + temperature; temperature +density), 3-channel (level, temperature and pressure/density) or 4-channel version (level, temperature, pressure and density).

The operation principle of the TGD™ is based on the patented principle of Guided Low Frequency (GLF™) wave propagation, which allows for equally precise measurements along the tank height of any shape of tank and type of liquid.

The TGD™ series provides highly reliable and accurate measurements of all parameters. Based on its use of acoustical wave technology for level, it eliminates many of the limitations inherent in other methods of level measurement.

Operating principle and features of GLF™ Technology:

  • GLF™ technology measures the difference in density between air and liquid
  • Tank geometry and objects inside the tank, such as ladders, heating pipes, etc., do not affect the signal
  • GLF™ technology ensures equal measurement accuracy of the whole tank – from top to bottom
  • Automatic calibration with high accuracy every 2 seconds
  • GLF™ technology is not affected by foam
  • GLF™ technology means a lower number of sensors have to be installed in the tank
  • Flexible solution with the possibility for the waveguide to be bent/curved

Main Advantages:

  • Automatic calibration
  • High level of accuracy
  • Less cabling – only 2 wires
  • No moving parts – longer lifetime
  • Flexible and easy installation
  • Explosion proof

UPT™ – Universal Pressure Transmitter

The UPT™ (Universal Pressure Transmitter) is used for the measurement and detection of the pressure in tanks and pipeline installations onboard or ashore, for level measurement (hydrostatic method) in service, ballast and slop tanks, as well as for draught measurement.

The housing and membrane of the UPT™ are made of stainless steel. The UPT™ can be supplied with various types of flange and thread connections, including a special extension for installation on top of tanks and reservoirs.

Special attention has been given to meeting demands for a high level of enclosure, robust, compact construction and resistance to shock and vibration where conditions of high overload and temperature variation are common.

The UPT™ is specially designed for IP68 applications and it meets the highest standards and extended requirements for arctic and cold climate operation within industrial equipment, marine and off-shore applications.

Main Advantages:

  • General purpose pressure transmitters
  • Easy installation
  • Customized solutions
  • Superior performance
  • Application versatility
  • Plug-in electronic module

UTT™ – Universal Temperature Transmitter

The Universal Temperature Transmitter (UTT™) is used for the temperature measurement of various media – water, oil, petrochemicals, acids, alkalies, gases and steam.

The UTT™ is characterized by a reinforced housing manufactured in stainless steel and the option of open-air installation.

The option of ordering the sensor with the required probe length, with or without a thermowell, in explosion-proof or standard construction, with any thread or flange connection makes the UTT™ the most convenient solution for most ship applications.

Main Advantages:

  • General purpose temperature transmitters
  • Easy installation
  • Customized solutions
  • Resistant to aggressive media
  • Resistant to temperature drop
  • Easy connection to most interfaces

Local Level Gauge

This Tank Level System is well suited for application in marine and general industry. The stainless steel sensor can be used for water, ballast water and other liquids.

The tank level system consists of a sensor, which is mounted on the tank. This converts the hydrostatic pressure of the liquid in the tank to a display on the manometer, thereby giving a continuous measurement of the contents of the tank. View can be calibrated to display pressure, fluid height and volume content.

Tank Level System:

  • The Tempress A90 Tank Level System has been designed and constructed using AISI 316 stainless and acid-proof steel
  • Requires no power
  • No floats or probes
  • Completely automatic
  • Can be used in all level applications with freely ventilated tanks
  • Calibration after requirements