Does anyone here have experience with electronic instrumentation?

[black22rifle]

Does anyone here work with electronic instrumentation either as an engineer or technician? I have an upcoming test on electronics and instrumentation which is a Ramsey test. I called Ramsey and they could not give me any info in regards to the material I would need to study. As far as electronic fundamentals in AC and DC are concerned I am pretty sound, but I dont have too much experience with instrumentation. I am familiar with oscilloscopes, wave generators, power supplies, prox sensors, and a few other things, but that's about it.

[SilverBullet432]

I have an AAS in I&E.

What type of "instruments" do you want to know about?

When I hear "instrumentation", I think control valves, pressure transmitters and end devices. Wireless radios etc..

[black22rifle]

By Instrumentation I mean having to do with manufacturing, so pressure , flow, float, level, temp sensors. I was told the test will be on "electronics and instrumentation" and I really don't even know where to start. As far as having to do with manufacturing these devices will be hooked up to PLCs and motor control systems which I am familiar with. I am not too familiar with sinking and sourcing so I will have to study up on that, too.

I have a few electrical engineering books, but they don't go into instrumentation, its all circuits and theories. I was looking online for some free e books on it, but I didn't find much.

[SilverBullet432]

By Instrumentation I mean having to do with manufacturing, so pressure , flow, float, level, temp sensors. I was told the test will be on "electronics and instrumentation" and I really don't even know where to start. As far as having to do with manufacturing these devices will be hooked up to PLCs and motor control systems which I am familiar with. I am not too familiar with sinking and sourcing so I will have to study up on that, too.

I have a few electrical engineering books, but they don't go into instrumentation, its all circuits and theories. I was looking online for some free e books on it, but I didn't find much.




Okay, I'd read up on how flow meters work, coriolis meters, turnbine meters and such.

There are various types of pressure switches out there, the most common one we use is a murphy brand.

For levels you can use pressure transmitters, guided wave radars, actual radars, float sticks or float switches.

For temperature there ate temperature transmitters, thermocouples etc..


As far as PLC sourcing goes: Really your sourcing your devices input from the PLC's output.


Lets say I have a relay wired to the PLC's DO1 digital output 1, when DO1 goes high (1) my relay will click and make something else go high,it could be sent through a wireless i/o radio to another device to shut it off. (Example: level gets too high in an oil tank; from analog input 1 (pressure transmitter) then fires do1 which sends the high bit (1) to my well which then fires do1 on my wireless i/o which then shuts the drive down on the well)

[Ryno12]

Most of that stuff is low voltage applications.
You'll want an understanding of:
RTDs, thermocouples, etc.
PID loops - how they work and are programmed
Analog vs discrete I/O - 4-20mA, 0-10VDC signals, etc.
Programming & scaling, dead bands, etc.

[Irish]

By Instrumentation I mean having to do with manufacturing, so pressure , flow, float, level, temp sensors. I was told the test will be on "electronics and instrumentation" and I really don't even know where to start...

I know a bit... Most of my stuff has to deal with 4 - 20ma positioners and I/P on control valves. I have calibrated flow meters, pressures, thermocouples and similar. I'm very familiar with HART protocol as well. I'll have more time later to throw out a few things and I'll try to help with any questions regarding stuff I know.

I work on the engineering side for a severe service control valve manufacturer. I deal with sizing valves a lot so inlet and outlet pressures, velocities, pressure drops and things of that nature...

[SilverBullet432]

Bump.

[1_click_off]

Not sure what the Ramsey test has on it.

I would guess you need to know these terms and what they are.

Span and Zero for adjusting analog signals.

Sinking and sourcing circuits.
Here is a good document on it. http://www.automationdirect.com/static/specs/sinksource.pdf

Raw units and Engineering units

Maybe how some popular types of thermocouples work. I see a lot of type J.

Same for RTD.

HART is a communication protocol that allows one to use the same wires the analog signal is on to make end device setting changes. If you have seen a sine wave on a scope this analogy may make sense. Think of the wave as the signal for the process and then there are tiny ripples on the much larger sine wave. These tiny ripples are the signal to the end device for it to be programmed with.

Maybe look at how to use resistors to change a 4-20mA signal to a voltage signal.

I am usually on the PLC side, but have to go trouble shoot end devices once in awhile.

I would add mag particle flowmeters to the flowmeter list above.

[black22rifle]

Thanks guys. I found this book at my local library but it is 20 years old so I'm guessing its outdated. I also found an online tutorial that's somewhat of a small book on instrumentation and process control so I have been reading and taking notes on that. The book I found is actually referenced in the tutorial.

https://www.amazon.com/Industrial-Instrumentation-Iu-Mechanical-Technology-Jerry/dp/0827361254

[SilverBullet432]

Not sure what the Ramsey test has on it.

I would guess you need to know these terms and what they are.

Span and Zero for adjusting analog signals.

Sinking and sourcing circuits.
Here is a good document on it. http://www.automationdirect.com/static/specs/sinksource.pdf

Raw units and Engineering units

Maybe how some popular types of thermocouples work. I see a lot of type J.

Same for RTD.

HART is a communication protocol that allows one to use the same wires the analog signal is on to make end device setting changes. If you have seen a sine wave on a scope this analogy may make sense. Think of the wave as the signal for the process and then there are tiny ripples on the much larger sine wave. These tiny ripples are the signal to the end device for it to be programmed with.

Maybe look at how to use resistors to change a 4-20mA signal to a voltage signal.

I am usually on the PLC side, but have to go trouble shoot end devices once in awhile.

I would add mag particle flowmeters to the flowmeter list above.




Ugh man I can't tell you how many of those Direct Logic 05/06s we've had to replace. Not to mention those CMORE HMI's they are crap!