Hi, I need help with my metrology assignment please The purpose of his as t wri

Question

Hi, I need help with my metrology assignment please

The purpose of his as t wri ut measurement systerms within the manufacturing industry 1. Description of measurement system (Equipment, Fixtures, Tools Software). 2. Description of the item being measured (What is it used for?) 3. You are to describe and evaluate the measurements being taken. In this section. explain why measurement is important Based upon your evaluation of the measurement system what are your thoughts? Is it sufficient to meet the produet needs?

Explanation / Answer

The measurement system can be defined as the all the components included from the interface to the
physical property being measured, pressure, vibration etc, to the recorded data storage. This not only
includes the physical devices, but the user as well.

The measurement system in its simplest form generates a human readable interface that can be used
for simple monitoring. In this simple system any data must be recorded by the operator. The
measurement system may include an electrical interface, allowing the data to be converted to some
other format, or in some other location before it is presented to the operator. Data in this configuration
is still recorded by the operator, but the additional level of complexity allows for a certain amount of
pre-processing to be completed. As we work through the various transducer technologies the range of
pre-processing that may be useful should become evident. As stated this configuration also allows the
measurement to be transmitted to some remote location. A simple example might be reading a
temperature. It should be obvious that there is simply no good way to read a glass thermometer from a
control room several hundred feet away, let alone several states or countries away. However if we
convert this measurement to an electrical measurement, we have techniques that will allow this
information to be transmitted to this remote control room, and under some conditions anywhere in the
world.
The third configuration is quickly growing to the most common method of measurement. With the
quick growth of computing power in the last ten years, it had become a relatively simple and common
matter to make these readings using a computer system and then relaying converted, scaled and
corrected data to the user, not only for the current moment, but also for a significant amount of the
measurement history, allowing for graphical trending as well as the raw single values of the past.
As you can see in the figure 1.1, there are a number of levels of interface that must occur between the
physical condition being measured, and the operator. Each of these blocks represents some form of
conversion of the data, either mechanical, physical or electronic. Each of these also represents an
opportunity for error to occur in the measurement.

As you can see in the above figure, this entirely mechanical system would show the position of the slider
portion of the slider crank on the indicating scale. Each one of the numbered interfaces, in this case
coupling flexible joints, introduces some amount of error. A tight joint introducing less error than a
loose joint. In addition the slider bearing fit could contribute some amount of error in the output scale
reading. Let us not forget the operator. Since the needle is always moving, the operator must make
some kind of decision as to when to read the scale, and can introduce unintended errors himself, by
anticipating the reading and not actually recognizing the true reading at the instant it is being read. We
will take a much closer look at all these potential error points in a later section, as well as how to
determine the amount of anticipated error, or uncertainty, in the reading.

Another concern of any measurement system is the resolution of the system. Again looking at the
system in figure 1.2, it should be easy to see that the more accurately we can number the scale for the
pointer, the more accurately we can read the position. It should also be fairly obvious that there will be
some physical limit where adding more little tick marks really won’t help, because they will have gotten
too small to determine. We might then increase the diameter of the scale, effectively spreading the
marks out, again allowing us to add more marks. Is there a realistic limit to how many times we can
increase the size of the scale and add more marks? The answer should be obviously yes. While each
step of increase in diameter allows more marks, the system reaches a point where the slop in the
system equals or exceeds a single increment on the scale. This is the effective readable limit of the
system.

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