Portable gas detection for larger workplace areas

Citation

(2001), "Portable gas detection for larger workplace areas", Pigment & Resin Technology, Vol. 30 No. 3. https://doi.org/10.1108/prt.2001.12930cad.014

Portable gas detection for larger workplace areas

Portable gas detection for larger workplace areas

Keywords Draeger, Hazardous materials, Health and safety, Alarms, Gases, Measurement

Described as incorporating powerful visual and audible alarms, the new Ampliwarn Mini Beacon from Draeger is reported to provide an immediate warning of the presence of toxic or explosive gases. Claiming a portable solution to the protection of several employees within a potentially dangerous workplace area, Ampliwarn is designed for use with a number of personal gas detectors such as Draeger's Pac II and III, Pac Ex and Multiwarn I and II.

Compact in size and easy to transport, the unit combines fibre optic technology within a rugged design (Plate 10). Triggered by the light alarm on the personal detector, the detector is said to emit a loud siren (100dB at one metre) as well as a red flashing light which can be seen through 360ú. According to Drager, in order to extend the working area, up to four units may be linked remotely to provide one master alarm unit. We are also informed that if required, the units can be linked directly to the control room or to a remote sounder.

Plate 10 The Ampliwarn Mini Beacon from Draeger provides an immediate warning of the presence of toxic or explosive gases

Stated to be approved to EEx ia IIC T6 for zones 7 and 2, this versatile unit is supplied complete with self-test functions and a 220V/50Hz charger. Claiming extended monitoring capabilities, it provides up to 800 hours of operation or, once an alarm is initiated, up to 75 hours of continuous alarm signal before requiring a recharge.

Draeger also informs us that it has added another four chips to its Chip Measurement System (CMS) range. Believed to be ideal for use in the chemicals industry to provide accurate, reliable spot measurements, these new chips enable this portable gas and vapour monitoring unit to measure hydrogen sulphide, ammonia, methylene chloride and styrene.

Requiring minimal user training, the CMS is said to be quick and easy to use. When plugged-in to the CMS analyser, which measures and evaluates the concentration, the chips reportedly provide an immediate, true digital readout without the need for further evaluation.

Low concentrations of hydrogen sulphide can be found in the production of sodium bisulfide, sodium sulfide, organic sulphur compounds such as thiophenes and mercaptans, sulfate cellulose and sulphur. As a starting compound for many chemical syntheses such as the production of sulfonamides, chemical fibers, sodium cyanide, nitriles and nitrates, etc., ammonia is also the product of the Haber-Bosch production process using nitrogen and hydrogen. Both of these new chips will measure concentrations up to 0.2-5ppm.

Methykne chloride is used as a solvent for plastics, propellant for foams, and as an extraction agent. Styrene is produced via direct catalytic dehydration of ethyl benzene, and styrene monomere is a basic component for the production of many thermoplastics. The control of occupational exposure limits, process or product control and the need to check storage vessels, storage tank installations and flanges for their presence, can now be easily accomplished with the methylene chloride chip, which can measure concentrations of 10-200ppm, and the styrene chip which can measure up to 2-40ppm.

Combining intelligent operation with straightforward user instructions, the CMS features a back-fit, multi-lingual LCD display and a menu-driven user interface. Supplied pre-configured for automatic operation, the analyser is said to perform a self-check on system start up and, as soon as the chip is inserted, carries out a chip integrity test.

Incorporating a mass-flow regulated pump, the CMS reportedly measures the movement of concentration in relation to time, regardless of fluctuations in atmospheric pressure. This constant mass flow capability, together with the sensitivity of the reagent system, is said to enable fast, extremely accurate measurements to be made. Once measured, the result is displayed as a concentration on the digital display. In addition, before carrying out a measurement, the system allows the user to select the way in which data is stored.

A tone signal sounds at the end of each measurement cycle and, at this stage, another measurement can be made or another chip selected. A wide variety of chips are available for different applications. Each chip carries a bar code which, when decoded by the analyser, provides the parameters for the measurement evaluation such as the gas type and measurement range. Able to carry out ten separate measurements, the chips are stated to have a two year lifespan.

For those applications where liquids may be present, a special float probe can also be supplied. Protected against dust and spray water in accordance with IP54, the CMS is believed to be intrinsically safe and resistant to electromagnetic radiation. It is also stated to carry Cenelec (Europe), UL (USA) and CSA (Canada) certification approval.

A third new product from Drager is the Saver PP positive pressure Emergency Escape Breathing Apparatus (EEBA) from Draeger Safety which is described as being designed to provide safe and unhampered escape from hazardous environments where breathing has become difficult or endangered. Claiming high performance protection against potentially hazardous gases and vapours in any application, the Saver PP (Plate 11) is said to combine leading edge technology with reliability and ease of use.

Plate 11 The new Saver PP positive pressure Emergency Escape Breathing Apparatus (EEBA) - from Draeger Safety

Developed by Draeger in consultation with end users, the Saver PP is reported to be fully operational as soon as the carrying system is opened and is simple to reset in the event of a false alarm. Housed within an instantly recognisable orange bag complete with photo-luminescent panels, it is said to be easy to locate in very low ambient light or poor visibility conditions and can be used with other forms of personal protective equipment (PPE) such as helmets and ear protectors.

Featuring the same pneumatic components as the new PA90 Plus Breathing Apparatus, this lightweight, compact escape system claims to provide low breathing resistance and a consistent air flow rate at all cylinder pressure levels. In addition, the pressure reducer reportedly ensures excellent flow characteristics whilst the positive pressure Lung Demand Valve has a balanced piston design which is first-breath activated and extremely quiet in use.

Supplied complete with Draeger's Panorama Nova facemask the Saver PP also claims low exhalation resistance, a close and comfortable fit and a self-demisting visor for clear vision. In use, the pressure gauge can be inspected quickly and easily, without dismantling or adjustments, via a transparent viewing window on the outside of the bag. Once depleted, the cylinder can be charged using standard charging connectors.

Believed to be ideal for use in any industrial environment, the Saver PP is stated to be fully approved to EN402 and can be supplied with ten or 15 minute duration as well as a wide range of accessories. These include storage cabinets for both indoor and outdoor use, spare cylinders, and an anti-static bag for use in potentially explosive atmospheres. A waist belt can also be provided as an option to prevent excessive movement when the set is worn in the ready position.

Details available from: Draeger Ltd. Tel: +44 (0) 1823 481248; Fax: +44 (0) 1823 481120.