ACG+

Monitor for Compressed Breathing Air

A simpler approach to breathing air monitoring

Move away from time-consuming tube testing and costly lab analysis, and switch to a reliable, accurate monitoring solution designed to support compliance with EN12021, DEF-STAN 68-284, CGA, CSA, and OSHA standards.

In environments where compressed breathing air must meet strict quality requirements, consistency and reliability are essential. The Analox ACG+ has been developed to meet these demands, providing dependable performance alongside straightforward installation and maintenance.

Key Features

Continuous 24/7 monitoring
Low maintenance with simple installation and servicing
90 days of data logging, easily accessible via USB
Cost-effective alternative to colorimetric tube testing
Available as fixed or portable units
Compatible with any breathing air compressor
Clear digital display

Analox ACG+ compressed breathing air monitor for continuous oxygen, carbon monoxide, carbon dioxide, VOC and water vapour monitoring

Atmosphere control unit gas analyzer front and side view with dimensions displayed

Get a Quote

Support

Following our recent US office relocation, all accounts receivable payments must be directed to our new address:

4153 Bluebonnet Drive, Stafford, TX, 77477

Please update your records accordingly.

Information

Datasheets & Manuals

Datasheet

ACG+ Datasheet

Manuals

ACG+ User Manual
ACG+ Quick Start Guide

Software

ACG+ Software Tool

Warranty Information

Warranty Information Guide

Technical Specifications

ACG+ Unit

Feature	Specification
Power	24V DC
Optional battery power	NiMH or Li-ION
Optional mains adaptor	Universal input 95 to 250 V AC, 50/60 Hz
IP Rating	IP45
Response Time	T90 <120 seconds T90 <15 minutes H2O sensor
Temperature	Operating: −5 °C to 50 °C / 23°F to 122°F Storage: −10 °C to 60°C / 14°F to 140°F
Flow rate	0.5L per minute (max)
Inlet Pressure	5-10 Bar Gauge (Optional regulator can be purchased)
Humidity	0-99% RH (Non Condensing)
Outputs	1 x normally open relay contacts 1 x normally closed relay contacts 3 x 24 V DC switched output

ACG+ Sensors

Feature	O2 Sensor	CO2 Sensor	CO Sensor	VOC Sensor	Water Vapor Sensor
Range	0 to 50%	0 to 1000 ppm	0 to 20 ppm	0 to 100 ppm	0 to 100 mg/m3
Accuracy	±(0.035% O2 + 1% of reading + ±(0.035% O2 + 1% of reading + 0.15% of reading/°C)	±(25 ppm CO2 + 1% of reading + 1 ppm CO2/°C)	±(1 ppm CO + 5% of reading + 0.1 ppm CO/°C)	±(1 ppm VOC + 5% of reading + 0.25% of reading/°C)	±(0.15 mg/m3 H2O + 20% of reading)
Technology	Analox MEC intelligent electrochemical oxygen sensor	Analox 5S3 intelligent NDIR sensor	Analox MEC intelligent electrochemical sensor	Analox MEC intelligent PID sensor	Water vapour sensor using capacitive technology

Additional Information

A Proven Solution

Analox has extensive experience supporting military operations in a wide range of environments. For more than 30 years, we’ve worked alongside defense organizations across more than two dozen nations. Today, Analox systems are in use aboard vessels operated by the Royal Navy, Royal Norwegian Navy, Royal Netherlands Navy, and United States Navy.

The ACG+ has been engineered by our team of specialists to perform across multiple applications and operating conditions.

In 2021, the International Association of Oil and Gas Producers (IAGP) introduced updated standards for diving operations. The ACG+ continues to support commercial diving professionals in meeting these requirements on a daily basis.

Reliable, Continuous Monitoring

The ACG+ provides continuous monitoring of up to five gas parameters—oxygen (O₂), carbon monoxide (CO), carbon dioxide (CO₂), volatile organic compounds (VOCs), and water vapor. Results are displayed in real time, supporting both routine operation and calibration.

By removing the need to send samples away for analysis, the system helps reduce delays and operational downtime.

Traditional colorimetric tube testing is also eliminated, significantly reducing the potential for human error while removing the need for time-consuming spot checks.

With simultaneous multi-gas monitoring and automatic data logging, the ACG+ provides operators with consistent visibility and confidence in air quality.

A Cost-Effective Approach

The ACG+ combines multiple monitoring functions into a single system, reducing the need for separate analyzers, consumable test tubes, and extended maintenance periods.

Available in both fixed and portable configurations, the system offers flexibility for a range of installation requirements, including confined or space-limited environments.

Designed for Ease of Use

Installation and maintenance are designed to be as straightforward as possible. To support this, Analox provides 24/7 technical assistance, ensuring help is always available when needed.

Each gas measurement system within the ACG+ operates independently. This allows individual sensors to be replaced without affecting the rest of the unit, minimizing unnecessary downtime.

A Trusted Choice

The ACG+ has been widely deployed across military and commercial applications, where reliable and continuous gas monitoring is essential. Its combination of performance, simplicity, and versatility makes it a practical solution for decision-makers responsible for safety-critical environments.

Applications

Diving
Emergency Services
Manufacturing
Paint Spraying
Ships
Medical

Obsolete Product Manuals

Obsolete Product Manuals

Frequently Asked Questions

Can the ACG be used to test the quality of breathing air used to protect personnel from hazards posed by a hazardous substance covered by the COSHH regulations?

In part yes, the ACG can measure the quality of breathing air to the standards required for the gasses it measures, O2, CO2, CO, VOC’s and H2O. The required standards listed in the Approved Code of Practice (ACOP 9) are the same as BS EN 12021. Where the risk assessment for a process highlights a gas that is not measured by the ACG. I.e. a hazardous substance used, produces a harmful gas in quantities greater than safe exposure limits, such that it is a danger. Depending upon the gas in question it may be possible to test for the gas using the ACG’s sample support function with a colorimetric tube specific to the gas. If this is not possible then the ACG would not be suitable as the only test method employed under the COSHH regulations.

How often would you suggest I take an oil mist sample at the ACG’s sample support port?

The frequency of routine sample testing depends upon the level of usage of the compressor, how close to the design limits it is used and the scale of impact that contaminated gas would have on the compressed air system to which it is attached. As a minimum we would recommend performing an oil mist sample test at least once every three months, to coincide with the calibration checks of the other sensors in the ACG. Another good practice is to perform an oil mist sample test when the water, CO or VOC sensors alarm as they may be indicating a compressor problem, particularly if the source of the alarming contaminant is not obvious.

Can I use an ACG+ to monitor compressors using synthetic oil?

Because many of the mechanisms that generate oil vapor/mist also generate other contaminants such as VOC’s, CO and water vapor, the ACG+ is suitable for monitoring compressors using both synthetic oil and mineral oil. The ACG+ monitors for these contaminants which, when detected, can give an indication that problems may be present with the compressor (resulting in the generation of oil mist). These indications can be used as a prompt to perform an oil mist test using the sample support feature.