Precision Liquid Level Indication in Marine Environments

Portalevel® MAX MARINE PLUS is a highly capable, handheld liquid level indicator with ABS Type Approval for marine applications in level monitoring. Portalevel® MAX MARINE PLUS is fast, accurate, and reliable; with a survivable construction and cutting-edge ultrasonic capabilities, it allows an operator to non-invasively monitor the liquid level of almost any CO2, Halon, or Clean Agent fire suppression system at sea.

P/N: 2290334-COMXPSM
NSN: 6680-99-192-2735
IMPA MSG P/N: 652776


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The Benefits of Portalevel® MAX MARINE PLUS

Portalevel® MAX MARINE PLUS uses our latest developments in ultrasonic technology to provide liquid level indication with both extreme precision and ease-of use. Portalevel® MAX MARINE PLUS is:

  • Highly accurate to ±1.5 mm
  • Handheld and portable, requiring just a single operator to take measurements
  • Adaptable to application across different size cylinders and agents with 3 calibration modes and 4 power settings
  • Easily operated to find the liquid level in less than 30 seconds
  • Equipped with an extension rod for measuring banked cylinders
  • A non-invasive measurement solution requiring no downtime for the fire suppression system
  • Compatible with the Portasteele® CALCULATOR to calculate agent weight and ensure regulatory compliance
  • Robust and rugged for operation in the harshest of marine environments


Delivering Safeship®

Fire is the second greatest cause of loss of life and property at sea, after sinking. Because of this, we have developed our mission of Safeship® to minimise maritime loss by applying innovative solutions to the industry. As part of this mission, Portalevel® MAX MARINE PLUS is one of our flagship products, which aims to improve the safety and efficacy of marine fire suppression systems and in turn minimise losses due to fire. The combined accuracy, versatility and operational simplicity of Portalevel® MAX MARINE PLUS make it a solution which can be easily applied with minimal impact on the operation of a marine structure to facilitate a higher level of operational safety.

Talk to our sales team to find out more about Portalevel® MAX MARINE PLUS and Safeship® and how they can be applied to your operation.

What's In The Box

  Portalevel® MAX MARINE PLUS Main Unit:
  Portalevel® MAX MARINE PLUS Handheld Sensor:
  Extension Rod With Sensor:
  Ultrasonic Couplant:
  Infrared Thermometer:
  User Manual:
  Calibration Certificate:
  Robust Carrying Case:

Technical specifications

Technical Specification

167x82x30 mm (L x W x D)

Unit Weight

300g (with batteries)

Power Supply

1 x PP3 9V battery

Battery Life

10 hours continuous use

Sensor Type

Standard Sensor: 14mm Magnetically Mounted

Extension Rod With Sensor: 12mm Sensor, 0.9m Extension Rod

Sensor Connectivity

Standard Sensor: 1 m BNC coaxial cable.

Extension Rod With Sensor: 2.5m BNC coaxial cable

Sensor Frequeny

1 MHz

Operating Temperature

-10 °C to +65 °C (14 °F to 149 °F)

IP Rating

IP 65 Enclosure


55 x 28 mm backlit LCD


±1.5 mm (±1/16 inch)

Classifications & Approvals

UL Listed, RINA Classification Society Approval, ABS Type Approval


CE, UKAS, Coltraco is ISO 9001 and ISO 14001 registered

  • Main unit – 3 Year Warranty
  • Sensor – 1 Year Warranty
  • Technical Support – Lifetime of the unit

See the Portalevel® MAX MARINE PLUS in action.

Frequently asked questions

The Portalevel® MAX MARINE PLUS can measure the level of a wide variety of liquids. The primary application is for checking the liquid level in fire suppression cylinders. These agents commonly include: CO2, FM200™, NOVEC™ 1230, Halon agents, FE-13™, FE-25™, NAF S III™ and, all core Clean Agent systems. However, the Portalevel® MAX MARINE PLUS has been shown to work on other liquids such as water, fuel, LPG and even mayonnaise in the processed food industry.
The Portalevel® MAX MARINE PLUS can identify the liquid level to ±1.5 mm of the actual liquid level. When using the Portasteele® CALCULATOR to convert the liquid level to agent weight, the results are accurate to within 1%.
With the Portalevel® Max Marine Plus, you also get an extension rod that allows you to measure the liquid level in banked cylinders up to four deep.
The Portalevel® MAX MARINE PLUS is one of the most powerful we have developed and works on a large range of cylinder sizes. We have an extensive range of products that can measure anything from 10 cm to over 15 m diameter, so get in touch to find out which unit is suitable for your application.
No, you can use any ultrasonic gel, available in most pharmacies, as well as petroleum jelly. Water will also work, but in hot environment needs very regular application.
No, unfortunately above this temperature CO2 converts into a supercritical fluid state and your cylinder will no longer have a liquid level to measure. We recommend testing CO2 in lower temperatures. Please, get in touch if you need recommendations for hot climate CO2 monitoring.
Yes, however, these agents are far more stable at higher temperatures that CO2, and although the liquid level will naturally rise with increased temperature it is far less than with CO2 and, therefore, can still be tested.
Yes, this unit is specifically designed to work despite the presence of a siphon tube.
The three calibration modes are deigned to offer greater flexibility for the Portalevel® MAX MARINE PLUS to test a wider range of cylinders, despite challenging measuring conditions. CAL 1: This is the standard setting to be used in most cases. This will work when the trend in readings you observe goes from high to low with a large drop-off CAL 2: This mode is to be used when the difference between high and low readings is great, or if CAL 1 is insufficient. CAL 3: This mode is to be used when the difference between high and low readings is small, and/or CAL 1 or 2 is insufficient.

Related Products

The Portalevel® INTRINSICALLY SAFE is an ultrasonic liquid level indicator approved for Zone 1 ATEX hazardous or explosive environments.

P/N: 2290334-IS

The Portasteele® CALCULATOR is the perfect partner to any of Coltraco Ultrasonics’ liquid level detectors. It allows you to convert your measured liquid level to an agent weight, precisely and accurately. These readings can then be saved and exported for future reference and traceability. 

Used in partnership with the Portalevel® Ultrasonic Level Indicator range 

P/N: CALC-007

Portamarine® is a low-cost, portable, and battery powered liquid level indicator designed to non-invasively, accurately, and reliably measure the level of fire suppression agent contained within a cylinder. Portamarine® is suitable for most standard size cylinders containing CO2, Liquified Clean Agents and Halons and is specifically equipped for use onboard marine vessels and environments in the marine sector.

P/N: 2290334-COPM
IMPA MSG P/N: 652777