Just because something is new does not mean it is better, says Mipac Senior Instrument Engineer George Wood.
With almost 40 years’ experience in instrumentation and design, he has firm opinions about advances (and otherwise) in instrumentation and design.
Here he shares his views on significant changes to the industry, identifies what’s working and what’s not, and casts a critical eye to the future.
Design
The impact of new technologies is most evident in the design of instrument systems. When I started in this profession, drawings were produced by hand and only large engineering companies were starting to use CAD.
CAD machines were big, expensive, purpose-built units located in special ‘clean’ rooms and only the top designers were trained in their use.
Special lighting and furniture added to the futuristic feel of a CAD office. The large, flatbed plotters were always entertaining to watch and I guess any cost advantage in producing the drawings with CAD was quickly lost when a small crowd would gather to watch the flatbed plotter perform its erratic magic.
These days it is impossible to imagine an engineering workstation without a PC, or drawings being produced using a set of Rotring pens and stencils on a large adjustable drafting bench.
There was a grab bag of ‘high on claim but low on delivery’ database engineering design packages a few years ago but now, although still a little clunky, design packages have reached a stage where they are cost-effective and save time. Their use will become more widespread as they become easier to tailor to individual project
Instruments
In recent years instrument manufacturers have introduced set-up procedures that are common throughout their instrument range. Combined with the on-board smarts of modern instruments, common procedures make calibration and commissioning much easier.
Internal fault detection is another area where technology has advanced to a point where many instruments indicate to the technician what is wrong or as least where to start looking for the problem.
Technological advances have made instruments more accurate, robust and easier to use but many times I have seen good instruments installed badly. An instrument installed in the wrong location or just installed poorly results in reduced accuracy and/or a shorter operational life.
That’s where Mipac comes in, ensuring the best instruments are selected and installed properly in the right location. It also helps if clients RTFM (read the flaming manual!)
Fieldbus
Fieldbus technologies are becoming common and they have a few advantages but they are not yet the silver bullet for instrument signal transfer. This is partly because there is a huge amount of information available via fieldbus instruments but this information is seldom accessed by the end user.
Sometimes fieldbuses are used because they are the latest thing and so people think they must be better than old-fashioned 4 to 20mA circuits. I have been to sites where the blind drive to use a fieldbus outstripped common sense. This resulted in more cable runs and junction boxes than necessary due to equipment location and because some field instrumentation didn’t have that specific fieldbus as an output signal option, the fieldbus cables and the 4 to 20mA trunk cables were run into the same locations.
Mipac does not have a vested interest in selling a particular system or technology so our engineers always consider every issue and every possible solution. The best solution may not involve the latest technology and fieldbus may not be the best way forward!
Training
I know of one remotely located plant where the fieldbus system was removed and replaced with 4 to 20mA circuits because the local maintenance guys didn’t have the knowledge and skills to keep the system running. There was nothing wrong with the fieldbus system, just a lack of training for those responsible for looking after it.
As companies tighten maintenance budgets there is more reliance on electricians to be across the electrical distribution system and electrical controls, and also the instrumentation and control system. Many have had no formal training in instrumentation and generally try to ‘pick it up as they go along’. There were once a few specialist electricians who completed a dual trade in electrical and instrumentation engineering but sadly these ‘dual trade’ guys are getting harder to find. (They are buying a Harley Davidson and riding off into the sunset!)
Mipac offers clients the best of both worlds — experts in electrical engineering and instrumentation design. We also offer on-site training as well as remote support.
The future
I predict change in the following areas:
- As battery technology advances and more power can be stored within instruments, wireless instrument systems will become more common.
- Engineering design packages will be the tools used to design instrument systems.
- The large centralised control rooms will disappear and they will be replaced by portable HMI units used ‘in plant’ by operations and maintenance personnel.
