Fixed Weight Monitoring System for Inert Gas, CO2 and other Clean Agent Cylinders

The most accurate and fast acting constants loss monitoring system of its kind. Capable of detecting a loss of agent mass to within 1% in Inert gas, CO2 and Clean Agent systems, and in addition to weigh loss, will provide accurate percentage pressure loss of Inert gas systems associated with agent contents leakage.

P/N: 2594650-FW

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Fixed Weight Monitoring for Fire Suppression Systems

Cylinder agent leakage can cause an entire fire suppression system to malfunction, and if undetected could result in an ineffective release of agent that may fail to extinguish a fire. A catastrophic leakage event that dispels entire contents of a cylinder is immediately apparent; however, slow leakage over time is very hard to detect. Slow leakage resulting in a 10% decrease in CO2 agent mass requires complete replacement of the system and 5% if using clean agents or Inert gas systems. Therefore, it is imperative to be aware of slow leakage to allow maintenance to take place before a failure occurs.

The PermaMass® FEATHERWEIGHT is our innovative answer to the need for continuous Inert Gas, CO2 and Clean Agent cylinder contents monitoring. We recognise the need for continuous asset protection and monitoring and having one master control unit to display the constant agent weight fluctuation in high-pressure gaseous system installations, covering up to twelve cylinders is industry leading. Merging fundamental mathematics to enable true constant monitoring along with cutting edge engineering that could be easily retrofitted, bringing you our latest addition to the complex continuous monitoring technology.

Monitoring the mass of your cylinder contents is a fundamental way of measuring agent loss, against the risk of accidental discharge or slow seepage of agent and is the only method that is not affected by pressure or temperature. This enables cylinders to be constantly monitored 24/7 with the PermaMass® FEATHERWEIGHT to ensure they are at designed capacity, but we also provide real-time information on the exact amount of agent in the cylinders to less than 1% accuracy above 10 kg agent weight or 100 g below.

During a leak event, the system will show you the exact amount of agent loss, including percentage loss in each cylinder, and if monitoring Inergen™, it will show pressure loss, which is intrinsically linked to mass, all displayed on a full-colour 4.3” display.


“Technology that is designed for total flood fire suppression systems in high-pressure seamless cylinders.”


  • Monitors up to 12 cylinders (48 by connecting  four main units together using one power source).
  • Accurate to 10 g or better than 1% above 10 kg total cylinder weight.
  • Converts mass loss in Inert gas systems into equivalent pressure loss.

What's In The Box

  Main Electronic Unit:Sophisticated electronic control unit capable of monitoring up to 12-cylinders and connecting four additional units together sharing one-power source. Communication ready for easy fire panel integration.
  Hanging Mechanism:Entire mechanical hanging kit needed to support and hang the cylinders under the weight sensors. Unique locking plates allow the user to quickly and easily remove the sensor without disconnecting the cylinders, saving down-time.
  Load Cell Sensor:Highly accurate 200 kg capacity (S-Type) strain gauge sensor used to send weight measurement data to the main control unit for processing.
  Kit consists of:2x Locking Plates 1x Cylinder Neck Ring 2x M12 Studded Support Bar Fixtures (nuts, bolts, washers) 200 kg (S-Type) loadcell

Technical specifications

Technical Specification

  • Height: 89.0 mm
  • Width: 213.0 mm
  • Depth: 53.3 mm
  • Weight: 700 g

Self-Extinguishing Blend PC/ABS


115 ~ 264VAC 120 ~ 370VDC.

Operating Voltage

24 V.

Frequency Range

47 ~440 Hz.

Connectivity Options

Volt-Free Relay (Dry) Contact (NO/NC)

Operating Temperature

-20 ~ +50°C

Operating Humidity

20 ~ 90% RH Non-Condensing

IP Rating

IP 54 Max (IP 66/7 Rated Case)


4.3 Inch TFT

Mounting Options

DIN (EN 60715) Rail


±100 g (1% >10 kg agent)

Monitored cylinders

1 – 12 Cylinders

Power Relay

4-Units (48-cylinders on single power source)

Cylinder Hanging Mechanism Data


Hanging Mechanism



200 kg (S-Type) Loadcell Sensor



Customisation is available


Kitting Weight

~320 – 360 g (including S-Type load cell)



Mild Steel


Collar Internal Thread

W80x1/11 Grade


Internal Collar Diameter

78 mm (standard issue)

See the PermaMass® FEATHERWEIGHT in action.

Frequently asked questions

No. The reason this type of weight measurement is not effective onboard marine vessels is due to the movement of the vessel. All weight measurement type systems are prone to error due to regular motion either vertically or laterally. This will cause fluctuations and false readings on the device. Our R&D team is actively looking into this application.
Yes. The PermaMass® FEATHERWEIGHT can be used in the marine industry as long as the installation and conditions are stable, unlike a floating vessel. Offshore Oil & Gas installations are suitable depending on their ATEX requirements.
No. The PermaMass® FEATHERWEIGHT is not intrinsically safe and cannot be used in a Hazardous (Zone 0,1,2) areas.
The PermaMass® FEATHERWEIGHT is designed to monitor non-liquified clean agents, otherwise known as Inert Gas (Inergen belnds), liquified Clean agents with Nitrogen, such as NOVEC™ 1230 and FM-200™, and CO2 . Please, contact Coltraco directly if you require the monitoring of other agent types.
Yes. The cylinder must be high-pressure seamless with a total weight of less than 200 kg (the limit for the loadcell sensor). For Inergen, the agent weight should also be above 10 kg. The cylinder must also have a threaded neck under the valve. If your cylinder thread does not match our standard cylinder collar thread, please contact us directly to discuss customisation options.

Related Products

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P/N: 2290334-COMXPS
NSN: 6625-99-257-8336
IMPA MSG P/N: 652776


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

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