The City Technology 4CM Carbon Monoxide Sensor: Safety Fast

Speed is of the essence.

A truism applied to many different situations, but a statement that is arguably critical in life safety applications, where procrastination or delay can literally prove to be fatal. Carbon monoxide, a colourless, odourless, tasteless, and initially non-irritating gas is very difficult for people to detect. Exposure to 100 ppm or greater can be dangerous to human health, and as the symptoms of mild exposure include light-headedness and confusion, while larger exposures can lead to death, the provision of an effective CO detector is an imperative for personnel who may encounter it during the course of their work.

Industrial safety is one of the most important areas for CO detection. The gas is to be found in mining facilities, oil and gas plants, petrochemical facilities, steel plants and wastewater treatment plants. It is also a major potential hazard when personnel are required to enter confined spaces.

4CM

Improving on existing City carbon monoxide sensors and providing OEMs and end users with better performance than competition was the driving force behind the development of the new 4CM CO sensor. Extensive testing confirms that the objectives set in the design brief have not only been achieved, but have been exceeded by a considerable margin.

In every critical performance metric, 4CM out-performs the competition, offering high performance sensing for challenging environments. Add in the intangible benefits of dealing with City Technology: providing technical and commercial support for 21 hours per day through five regional sales offices and backed by a $40bn technology and industrial market leader, it’s not difficult to see why City is the global leader in gas sensing technology and manufacturing. 4CM is manufactured on a fully automated line in the UK, giving full characterisation of every sensor, traceability down to the component level and guaranteed supply flexibility and uncompromising quality.

The 4CM key benefits are:

• Reacts 12% faster to CO hazards than other sensors on the market
Not only does the fastest reaction time to the presence of gas – a typical T90 time of seven seconds -give users critical extra time in the event of an emergency, but the recovery time is equally impressive, returning to an indicated level of <2ppm in under 100 seconds, less than half the time of the competition. Worker downtime is reduced, as they do not have to wait so long for the instrument to recover.

• Performs to specification whatever the operating environment
The 4CM demonstrates outstanding performance during prolonged 50-day exposures in 50°C and 11% relative humidity, hot and dry conditions. Even when exposed to 50°C at 95% relative humidity for 50 days, in hot and wet environments, the 4CM continues to operate to specification. Reduced warranty returns and prolonged sensor life takes out costs for both the user and instrument manufacturer.
• Less worker downtime through reduced out of the box and field failures
Infant mortalities and premature failures can cause users and OEMs to incur considerable costs. The highly automated 4CM manufacturing process achieves an out of box failure rate of less than 0.0008%.

At both high and low gas concentrations, the 4CM delivers unparalleled accuracy and reduced uncertainty in the output level. It easily meets the EN45544 requirements for uncertainty, typically achieving 1ppm for zero concentrations and less than 1% variation at 250, 750 and 1000ppm, a far better performance than competition. Stable performance in aggressive environments increases user confidence in the instrument and extends the operating envelope.

• Reduced calibration costs for manufacturers and end users
The speedy response to the presence of gas and the rapid recovery from exposure reduces user regular calibration and verification costs with an estimated 12.5% time reduction and a 6% material usage reduction. Typical savings are estimated at $50 per sensor per annum.

Optimised for use in demanding industries Life safety equipment has to perform reliably in some of the most demanding and aggressive environments: arguably, no industry is as difficult as Chinese mining, where the temperature and humidity extremes are extremely challenging. Recognising the unique demands placed on life safety equipment in Chinese mine complexes, the relevant specification, AQ6205-2006, is a searching examination of a product’s performance. It is widely regarded as the most severe set of requirements to be found anywhere; 4CM fully conforms to its requirements, enabling OEMs to specify it with complete confidence for use in any industry anywhere in the world.

Data is freely available to confirm that 4CM meets the critical test requirements such as:

• Power-off protection measures
• Repeatability: stability and basic errors of displayed value
• Determination of difference between the alarm limit and the setting value
• Cold and hot operation
• Low and high temperature storage test
• Alternating humidity heat test
• Performance versus temperature test
• Intrinsic error verification / linearity
• Gas concentration above the upper limit of the measuring range
• Extended operation in standard gas
• Determination of the working stability
• Humidity shock
• Signal stability

Summary

The 4CM is designed to meet the fundamental customer requirements for safety, performance and compliance by offering
• A rapid response and recovery time: the fastest in the market
• Excellent accuracy at high and low concentrations
• Reliable operation in high temperature and humidity environments
• Testing to EN 45544 and AQ 6205-2006
It reduces the cost of ownership through quality, delivery and support. Key benefits include
• Robustness to the most challenging mining conditions
• Fast response time in calibration and alarm reduces costs and improves safety
• Fast recovery time for calibration and operation reduces personnel down-time
• Field reliability leading to lower warranty costs
• Shorter lead times and flexibility in supply

Conclusions

Founded 35 years ago, City Technology, the global leader in the design, development and manufacture of gas sensors for personal life safety equipment, has consistently been at the forefront of the gas sensor industry, providing instrument manufacturers and users with innovative high performance sensors. 4CM is the latest new product to be developed; it out-performs both previous City CO sensors and competitors’ products by a clear margin. It provides instrument manufacturers and users with a robust sensor, which provides enhanced performance and includes features that improve the functionality, reliability and effectiveness of PPE - essential in the world’s most hostile environments. Electrical and mechanical backwards compatibility, stable output levels in temperature and humidity extremes and full conformance to the very demanding Chinese mining standard AQ 6205-2006 are key benefits. The 4CM continues City’s tradition of developing products that make a positive contribution to the preservation of life in challenging environments.

For more information Click Here