For tough industrial use

Personal monitoring for explosive and toxic substances is essential during all types of maintenance work in chemical plants and refineries. What is more, gas detection instruments are often also used for area monitoring – a bit like watchtowers – during work in industrial plants.

The X-am 7000 can be flexibly adapted to individual measurement tasks, with a choice of over 25 sensors available for detecting more than 100 gases and vapours. All the sensors used in this instrument – including the catalytic and infrared sensor types – are of the plug and play variety. The smart electrochemical, catalytic and infrared sensors allow many different types of data (calibration data, gas identification, alarm limits, measurement data, temperature correction etc.) to be stored in the EEPROM inside the sensor. The sensors are precalibrated and are therefore very easy to replace. Insert a sensor, and this universal detector is ready for all kinds of different applications, with no calibration or configuration required.

Gas detection instruments are also frequently employed to check waste water sewers, tank facilities, silos, pipeline and cable ducts and other confined spaces prior to giving the all-clear. Before personnel are allowed to enter, the gas atmosphere must be monitored – for lack of oxygen, toxic hazards or explosion hazards, depending on the type of confined space. The X-am 7000 gas detector, with its integrated high-delivery pump which can be easily retrofitted and replaced, is ideal for such all-clear measurements. The instrument draws in the sample gas through an extension hose up to 45 m in length. If pump delivery is too low, a flow alarm is triggered. A selection of different probes allows the instrument to be adapted to individual needs.

In industry, running costs are increasingly an issue which has to be taken into account when purchasing gas detection instruments, so it is little surprise that a clear trend towards non-contaminable infrared sensors is now evident. These sensors can be used both for measuring explosion hazards and for detecting carbon dioxide. Infrared sensors have no moving parts and feature gold-protected sensor optics which are resistant to poisoning even in tough industrial environments. In addition, this type of sensor offers long calibration intervals (six months), coupled with extremely long sensor lifetimes with a five-year guarantee. Unlike catalytic Ex sensors, infrared Ex sensors can detect potentially explosive atmospheres regardless of the oxygen content of the analysed air. Organic gases and vapours are absorbed by infrared light. In areas where explosion hazards are likely as a result of hydrogen and acetylene, however, there are limitations on the use of infrared Ex sensors, as these substances are not absorbed by infrared light, making this a typical application for catalytic Ex sensors.

One practical example of the use of catalytic Ex sensors is leak detection in natural gas pipelines. With this type of sensor the X-am 7000 can detect methane in concentrations around the lower explosive level (LEL). Many of the odorants added to natural gas can also be measured using the Dräger odorant sensor. In this application, the instrument is additionally able to detect toxic hazards caused by carbon monoxide and hydrogen sulphide.

An ideal solution for facility checks and monitoring measurements is the instrument’s leak detection mode. This mode allows the display to be switched from normal display to a graphic display – the bar chart advancing in 50 ppm steps. This function is supported by an ascending or descending tone to reflect the gas concentration, similar to that used in a Geiger counter. Thanks to the flexible goose-neck probe, even difficult-to-access areas can be reached in comfort.

The Dräger X-am 7000 is not only dust and splash-proof, but also completely water-resistant according to the ingress protection rate IP67. Water-repellent membranes protect the sensors if they are dropped into water. A protective rubber housing, which comes as standard, protects the instrument even if it is dropped from a height of 1.5 m. Since the sensors are not sensitive to shock, their measurement function will not be impaired if knocked. Accurate measurement results are in other words guaranteed whatever the conditions.

Where multiple shifts are worked, the number of operating hours and the time needed to recharge batteries are nowadays particularly important considerations. A long battery life with a high number of charge cycles helps reduce the costs of ownership, and intelligent battery management ensures that these requirements are met. The X-am 7000 informs the user of the remaining operating time and the available remaining capacity (as a percentage). Furthermore, the battery capacity is displayed in Ah. A key feature of this unique charge/discharge strategy is that the supply units are discharged in blocks. The six-hour battery contains 16 cells which are connected in four blocks of four cells (1.5 Ah). The blocks are discharged individually, one after another. As a result, the batteries are discharged fully, which prolongs their use. In addition, a precise calculation of the remaining battery capacity is possible. The instrument is charged at a current of 1 A, which means that the supply units can be recharged very quickly. The high charge currents also prevent dendrites from forming, thereby increasing the lifetime of the rechargeable batteries.

The three-key menu operation of the Dräger X-am 7000 is intuitive and easy to learn. The user can individually configure the password-free quick menu with those functions which are most important for the application in question. To make work simpler, the control keys can be operated without difficulty even when wearing heavy protective gloves. All messages appear in plain text and measured values are displayed permanently. In alarm situations, the instrument sounds a warning with a very loud multi-tone alarm. An additional visual alarm can be seen through 360°, making absolutely sure it will be noticed. Furthermore, maximum concentrations, e. g. TWA and STEV values, can be quickly checked.

The Dräger X-am 7000 features a declaration of conformity with an EC type examination certificate in accordance with the provisions of Atex Directive 94/9/EC, and protection classes II 2G EEx ia d IIC T4 and I M2 EEx ia d I. The instrument’s electromagnetic compatibility has been tested in accordance with Directive 89/336/EEC, and the instrument is CE marked. For the USA, the new instrument is UL approved as Class I, Div 1, Group A, B, C and D. It can be used in a temperature range from -20 to +60 °C.

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