Once upon a time this would have been an interesting question, today you may find it is not.
Of course, if you have a green light from purchasing to buy whichever manufacturer's product you like, then fire away but you may find it helpful to give some specific applications.
If all you want is a heads up about the major companies then your question is probably not going to get a sensible technical answer but a commercial one.
The way the global companies work is to put together a comprehensive package of instruments (portfolio is a preferred term) and to offer themselves as single source suppliers.
There is no guarantee:
[ul][li]their products are the best (some may be, others may be fillers - products that complete a range)[/li]
[li]their products are the cheapest - as individual instruments they may not be and probably are not. What they sell is singles source benefits which means that buyers like them and the cost of purchase may result in a good overall price deal[/li]
[li] other companies may offer better or cheaper or both better and cheaper but not everyone likes to (or can afford to) shop around.[/li][/ul]
Some project engineers, accept that if they get 90-95% of the specification met then that is more cost effective than searching out that extra "fit".
Some don't have any choice due to "strategic alliances" with the major instrument supply companies; these require that if they need a certain product and the buyers company has it then that's what you will get.
You may even find that you will search out a particular sensor, order it and find that purchasing have substituted the alternative from the preferred supplier.
Don't knock the guy from a smaller company telling you his is a better product and it is cheaper.
It can be true.
It can also be true that he will offer better support.
Some of my business comes to me because the majors can't/won't support their products and/or don't have enough specialist skills in house. Quite often you will be isolated from the manufacturer by a "regional sales office" who will deal with your enquiry. The very nature of companies with a large portfolio is that often the guys selling may have so many different products from so many different manufacturing locations they have little or no real skills beyond catalogue selling.
Some times, if you are dealing with small order values, your best bet is not to go to the manufacturer's sales office but to identify what you think you want and then see if you can discover a local dealer or distributor (these are often companies selected to hoover up the crumbs the strategic alliances don't capture) who may offer far more technical help and real applications knowledge.
JMW
