There are many 100's of Ready Mix concrete sites in the UK. They provide the foundation for much of our buildings and roadways. It is becoming more common to inject the concrete with carbon dioxide during the mixing stage. Once injected, the CO2 undergoes a mineralization process and becomes permanently embedded, while shortening the cure time and increasing the concrete’s compressive strength.
Ready Mix Concrete companies (RMC’s) are required to enter the central mix drum in between wet batch cycles to clean them out and perform routine maintenance. These activities involve confined space entry and this industry has been a long time user of our four-gas personal portable instruments. Many of these users feel that a standard four-gas instrument is sufficient, because they will see a drop in oxygen as CO2 accumulates. The problem with this logic, though, is that the CO2 levels will be toxic long before it displaces enough oxygen to generate an Oxygen alarm. The CO2 LTEL is 5,000 ppm or 0.5% volume. In otherwise fresh air, the oxygen channel will read 20.8 % volume, instead of 20.9% volume – nowhere near an asphyxiation hazard alarm. In fact, the STEL for CO2 is 1.5% volume, so even if the CO2 level reaches that point, it will only cause a reading of 20.6 % volume oxygen. So even when there is an immediate danger from the CO2, the oxygen reading is still far away from an alarm condition.
The Riken Keiki GX-3R Pro is ideally suited to address these hazards. In addition to the standard confined space gases: LEL, O2, CO and H2S, the GX-3R Pro is also available with a specific CO2 sensor. The CO2 sensor specifically detects low levels of the CO2 associated with Ready Mix Concrete instead of relying on higher CO2 levels to trigger an O2 alarm.
The GX-3R Pro is so small and light it can easily be worn on the lapel in the breath zone without interfering with work
Plant rooms are often situated underground. This is by design to save space or by virtue of being built into existing basements or chambers. Underground Plant Rooms often contain an array of machinery such as Pumps, Boilers, Sprinkler Systems or Generators.View Story
Disclaimer : Information given in this article is for general guidance only, and is based on experience and is not intended to replace advise from professional gas sensor location experts and/or gas mapping services, that can provide accurate bespoke design.
For more information about positioning fixed gas detectors, further guidance can be found in the new Gas Mapping Standard BS 60080 (Fire and Gas Mapping ), IEC 60079-29-2 (Explosive atmospheres – Part 29-2: Gas detectors – Selection, installation, use and maintenance of detectors for flammable gases and oxygen), and also EN 45544-4 (Workplace atmospheres – Electrical apparatus used for the direct detection and direct concentration measurement of toxic gases and vapours. Guide for selection, installation, use and maintenance.). Additionally, The CoGDEM ( Council of Gas Detection and Enviromental Monitoring ) Guide to Gas Detection is an excellent general user guide for Gas Detection, written by those in the industry.View Story
Catalytic combustion sensors are the standard method for detecting combustible gases including Hydrogen, however in order to operate a minimum of about 10% Oxygen needs to be present. IR sensors are a good solution to this problem for measuring most combustible gases in an inert environment where O2 levels are below 10% volume but IR sensors cannot detect Hydrogen.
Riken Keiki offers several solutions around this problem.View Story