Search engines on the Internet

Dr. Thomas Beneke, Dr. Wolfgang Schwippert

Potentially explosive atmospheres are characterised by a predominance of certain conditions. Potentially hazardous chemical-physical conditions can arise, for example, if gas or dust/air mixtures are ignited as a result of electrostatic charges or of voltage variations in electric motors. Suitable protective or precautionary measures in line with the latest state of the art must there-fore be incorporated in all electrical systems installed in potentially explosive atmospheres. The parts and devices used for control, measurements, indications and sensing are consequently required to satisfy stringent requirements, primarily with regard to func-tional reliability, ventilation effectiveness and housing or enclosure technology.

When the aim is to establish the current state of the art or the current stage of development in a particular field of science and technology, the Internet – as an electronic medium that is accessible 24 hours a day and always up to date – can thus generally be expected to offer the ideal solution. It can only do so, however, if German and international producers and distributors make sufficient use of the medium and present relevant information in a form that is geared to actual needs. That the user has to have appropriate access rights goes without saying. The first step on the road to procuring information is to choose a so-called search engine. These engines „know“ thousands of keywords and generate lists of addresses of all matching Internet sites. Different search engines specialise in different areas. It is consequently often worthwhile consulting several engines, in order to extract the required information about a specific topic. We picked the following three search engines for the purposes of our study – Yahoo, Excite and Fireball.

It is just as important to formulate your search words correctly and to combine them in a meaningful way as it is to choose the right search engine. It should be remembered that the information published by German and non-German-speaking producers and distributors is presented side by side on an equal footing. By combining several different search words, it is possible to restrict the list of offered sites to the most relevant ones and thus to reduce the amount of time necessary to view the matches. It comes as no great surprise to discover that there are no standard rules for determining which inputs are needed in each particular case, or how the various search words should be formulated and combined. Every search engine demands its own notation, and the easiest way to learn it is to call up the program help function.

In order to find at least English and German Internet sites with our search, we began by choosing words that are identical in both languages. Our first two, arbitrary sounding-out keys were „explosion“ and „sensor“. When we typed in „explosion“ at Yahoo’s top level, the search engine came up with a tremendous number of hits, as was only to be expected. However, with a total of more than one hundred thousand Web sites, the hit rate was so high that there was no point in looking any further. Instead, we reduced the number of matches dramatically by ANDing „explosion“ and „sensor“ together. With nearly two thousand hits, this selection unfortunately proved to be equally unsuitable for any kind of practical analysis. Since the majority of firms also write their sites in English, we started a third attempt with an English technical term – „explosionproof“. At 36, the number of hits was finally slashed to a more manageable level. The same query with the Excite search engine produced 86 hits, including various ones that had also been found by Yahoo.

Almost all search engines allow you to narrow down certain criteria further, to define them in more concrete form or to refine them, for instance by restricting the search range to so-called categories. For the purposes of our study we restricted the word „explosionproof“ to sources in the chemical engineering sector. Yahoo offers a special hierarchical structure for such categorisa-tions. Searching in scientific engineering sources, for example, results in a much smaller, but more specific, set of hits.

User-defined restrictions are also possible by combining the search words in particular ways. We tried out this method in Fireball by selecting „all languages“. When we entered the word „explosionproof“ on its own, we found it in more than five hundred different sources. In order to pinpoint those sources that are of relevance for the reader interested in chemical engineering, we then restricted the search to a few combinations of „explosionproof“ and various words containing the syllable „chem“. The combination „explosionproof“ + „chemical“ yielded around one hundred hits, while „explosionproof“ + „chemical engineering“ produced just three matches which – contrary to our expectations – proved to be only of limited practical interest. The combination „explosionproof“ + „chemistry“ generated six hits, half of which were of no interest to non-academics. Our search for „explosionproof“ + „engineering“ resulted in slightly more than one hundred hits, many of which were identical to those found with „explosionproof“ + „chemical“. An analysis of the Fireball hits and a comparison with the results achieved with Excite and Yahoo yielded largely identical results in relation to explosion protection for control, monitoring and sensor technology, etc. The hits often concealed extremely diverse levels of quality as far as the scope and content of useful information are concerned, as well as links and hyperlinks to further information.

Following a more detailed examination, we were left finally with approximately 20 addresses offering information on the topic of explosion protection. Some of these described complete systems or plants that are based on bus systems and used to monitor and configure input/output devices.

Siemens proved to be a typical represen-tative of our Internet searches. The complete system presented on the Internet sites ranges from individual modules at the sensor level right up to the supervisory control room. Visitors to the sites can find all the essential information about the structure of the system and the units it contains. Several links offer additional theoretical information. Practical examples of similar approaches or concepts include the chemical engineering plant at Schering AG in Bergkamen.

On a more modest scale, the British firm of Expo Safety Systems offers more specialised types of explosion-proof parts and de-vices for gas cleaning and pressure systems. In addition to lists of types and functional principles, supplementary information is also provided by a series of links. In a short, one-page reference to a trade fair article, Pepperl + Fuchs, the industrial plant engineering company, draws attention to its explosion-proof field bus systems and to its special sensors and parts, though without actually going into any detail. Since there are no links, any visitors wishing for further information are obliged to contact the manufacturer personally in the traditional way. Malux, the Swedish group, presents its information about explosion-proof plants and equipment in a very striking fashion by simply listing the partners with which it cooperates, along with their explosion-proof product groups. Eleven different manufacturers of, for instance, explosion-proof display and control desks, thermostats, switchgear cubicles, valves and motors, are mentioned by name. Links that take the customer directly to the appropriate sites are unfortunately missing.

Many manufacturers of explosion-proof equipment place individual products in the foreground of their Internet sites, whereby the presentation styles range from bold, jazzy and geared to younger Internet users to factual information in the form of full data sheets about specific products or complete product lines. Schischek, for instance, uses a clear visual structure to refer to its explo-sion-proof product ranges and to their potential industrial applications. Visitors who want to find out more can simply turn to the cited e-mail address. Wavell Electric likewise merely presents its link elements and cubicles, measuring instruments, etc. in the form of lists, without providing any facilities for calling up further details directly by electronic means. Other firms present their product groups in greater depth. Sierra Instruments and Appleton, for example, publish information about their explosion-proof standard products in tables showing the individual devices and parts belonging to each product range. Visitors for whom this is not enough can click on links and download addresses in order to obtain further details, or alternatively send a message to an e-mail address.

Presentations in the form of catalogues appear to be the favourite among the manufacturers of special products. Schütz-Meß-technik, for instance, supplies instrument sets, one of which is an explosion-proof gas detection system. The Enmet Corporation, which offers explosion-proof components at various addresses, structures its information in a similar manner. Depending on the chosen search engine or on the hit which is selected for subsequent examination, Internet surfers can call up further information extending beyond a straightforward presentation of the gas measuring systems, and possibly even including product specifica-tions. Product information structures along the same lines are also resorted to by other manufacturers, such as Foxboro, who offer sensors for recording absolute pressure, SIG Positec, specialists in stepping motors who grant access to additional information via links, and Crouse-Hinds, whose presentation describes explosion-proof, illuminated monitoring, control and display panels.

The overall situation can be summed up as follows: in our extremely specific chosen field of explosion-proof systems and equipment is a whole host of firms that take advantage of the electronic communication and information tools meanwhile available on the Internet. Their presentations span the complete spectrum from mature Internet concepts to sites that are still at the experimental stage. The single most important criticism, however, usually concerns the lack of detailed information. Internet sites with a more user-friendly design would allow visitors to immerse themselves into the material as deeply as they wished with the aid of links, and to retrieve all the information they required according to their own particular needs. The traditional, direct wire to the manufacturer would still be open in the event of any queries that could not be answered in this way.

Numerous manufacturers seem to think their Internet sites are especially elegant if they are embellished with large amounts of graphical material. However, they evidently forget that – depending on the transfer mode and the hardware used by the surfer – it can take quite a while for the complete stream of pixels to be built up at the other end. The resulting delays could well cause potential customers not only to become fed up with the Internet, but also to lose interest in the supplier concerned.

•Siemens introduces its Profibus-PA field bus system, including components that can be connected to it. Various links are provided for calling up further information.

•Expo Safety Systems offers information about gas cleaning and pressure systems.

•A short presentation from Pepperl + Fuchs provides a brief overview of its sensors, interfaces and bus systems.

•Malux, the Swedish company, lists the partners with which it cooperates, along with a few key words that describe their products. There is no direct link to these partners‘ home pages, however.

•This address provides an initial impression of the extensive product range of Schischek Explosionsschutz. Industrial, pharmaceutical and chemical components are outlined in brief. More detailed information can be found at the specified e-mail address.

•Wavell Electric Ltd. presents socket-outlets, housings and small products.

http://www.appletonelec.com/products.html

•The Appleton Electric Company offers an insight into its wide range of electrical systems and accessories.

•Sierra Instruments, Inc. outlines its sensors and measuring equipment for industrial process control applications in words and pictures.

• Schütz GmbH Messtechnik offers sensors, instruments and measuring systems – notably for gases – for the international market in English at this address.

•The Enmet Corporation lists sensors, measuring equipment and detection and alarm systems for (toxic) gases.

http://foxboro.infotechsys.com/products/IAP10/full.htm http://foxboro.infotechsys.com/products/134LVD/full.htm

•Foxboro presents a number of sensor and instrument variants for gas pressures and liquid levels. Thanks to the detailed information about the product specifications, these pages make choosing the right components relatively straightforward.

•This Internet address lists the stepping and synchronous motors manufactured by SIG Positec.

•Crouse-Hinds presents monitoring and control panels for use in aggressive and/or potentially explosive atmospheres.

This list makes no claims to completeness. A crucial role is played both by the choice of search engine and categories and by the search words that are formulated. It is moreover important to remember that the results achieved by individual search engines can in some cases vary considerably within just a few days or possibly hours, even if identical search criteria are used.