1 reply to this topic

[nazari.at]

I want to know difference between smart instruments versus diaphragm seals and also smart instruments versus normal/usuall instruments. I am confused if there are any differences between smart and usuall/normal instruments. Are they the same?

[Art Montemayor]

Nazari:

 

I think you are either mixing up your understanding of instrumentation and controls or you don’t know much about it.  Either way, since my knowledge of instrumentation is weak I consulted with two of my brothers who are E&I experts and can offer the following to help you out:

 

You are either relating to a category of present-day instrumentation or to a type of instrument device.  This may be where you are getting mixed up with regards to the word “smart”.  When used in all capital letters, it refers to a specific device.  When used as a hyperbole or “marketing”, “stylish”, name it refers to present-day, modern instrumentation.  For example, refer to the attached article that describes today’s instrumentation as being “smart” – which is a misnomer, since all instruments are merely tools that inherently are stupid.  On the other hand, SMART = Signal Modulation and Re-ranging Transducer.  And these are are defined as open protocol devices on a single transmission line.

 

A SMART device is one that basically gives useful feedback information about the process (and device) back to the user via a computer/handheld device/DCS.  As such, these devices usually have a microprocessor inside.  A HART device is one example of a SMART device.  Other examples are Foundation Fieldbus and PROFIBUS.  These 2 protocols use a digital signal where HART uses a 4-20 mA signal (normally called an “analog”) but it is superimposed (by way of a HART modem) so it allows all the benefits of SMART while being incorporated in an analog environment.

 

So, it depends on what you mean by ‘smart’.

 

There is absolutely no relationship between diaphragm seals and “smart” instruments.  This is where you are getting all mixed up or have no notion of what the terms mean.  A diaphragm seal is a device used to isolate a process fluid from a measuring instrument.  It is basically only a physical barrier and doesn't qualify as an instrument.  You are confused because you are mixing “apples and onions” expecting to get a sum of total fruits.

 Using Smart Instrumentation.docx   121.74KB   9 downloads