Quick question: Is measering done on the basis of pressure?

There are some errors in your question, but I think I know what you are asking.

First of all, there is a basic difference between weight and mass. I am going to use the word "weight" where you used mass. The word "mass" in my explaination would not be correct. If I wanted to talk about "mass" it would require a bit more complicated explaination which I would be happy to do if you would like.

If you are measuring weight (or mass) (at a specific location), there is only one correct answer. It doesn't matter what method you are using, if you get a "lower result", one of them is simply wrong.

That being said, if you know the pressure (by some measurement) you can not calculate the weight without measuring an area. If you have the relevant area than calculating the weight is very easy.

You also have your relationship between weight, area a pressure a bit wrong. The equation is Pressure = Weight/Area (actually any force can be used in place of weight).

This means if I have a weight of 180lbs. and stand on a box with a area of 100 in^2 the pressure will be 1.8 lbs/in^2. If I stand on a smaller object, say a box with an area of 20 in^2 my pressure will be higher, in this case 9 lbs/in^2.

But the main point is that the phrase "measuring weight by pressure" is not correct. If you measure pressure, than you need to know an area or you can not determine pressure.

If you are designing a scale and have a mechanism that measures pressure, there is an easy way around this...

Simply make a fixed area. You can attach the tray where the weight goes to a rod with a specific area. Than measure the pressure exerted by the rod.

So normally, a measuring scale won't measure on pressure (or the surface), but if it would you could simply define the surface and you're set to make a correct estimation of the weight, no matter what the surface is.

In real and daily life, if I were to measure the weight of something, it would give the same result no matter what the exchanging(of information and date really) is.

Yes, I think you got it. There are several good ways to measure a force. Since weight is a force, you can measure it directly. Easy way to measure forces involve seeing how far a spring is stretched. A correct measure of weight will be independent of any measure of area.

I am not sure what you are asking in the second paragraph. What I was trying to say is that there is one correct value of "weight" that each measurement should give. Any measurement that does give this value is wrong.

(Unfortunately this correct value changes depending on where you are and sometimes when you take it. Fortunately as long as you are on Earth these changes are very small (i.e. 1/100 of a pound for something my size)).

If I were to measure the weight of 1000lbs and do this on a surface of 20square inch, both the scale as the object now able to touch with its full 'bottom' or put it upside down on a scale with area 100square inch and the top of the object is also 100square inch, the results would invariably be the same. That's 2nd paragraph.

Mass is independent of external forces, even speed, if the observer is moving the same speed and direction as the mass. Weight is dependent on the gravity field which varies + or - about 1% depending on where you are, at or near Earth's surface. Very low density substances such as styrofoam and areogel have some buoyancy in air which may be subtracted from the weight.
Conventions vary.

While spring scales have poor repeatability, they do measure weight. A balance scale (most scales are variations of the balance scale) measure mass except both have a typically small error due to different densities, volume and ratios, and thus not proportional buoyancy in air. The spring scale produces an error due to centripical (centrifugal?) force due to the rotation of Earth's Equator at a bit over 1000 miles per hour, unless you choose to subtract the cetrifugal force from the gravity and call the result gravity. Conventions vary. Please embellish, refute and/or comment. Neil

So it would never matter if you put a pyramid on a measuring scale the 'normal' way or on its tip?

That is correct.

A scale measure force (weight is a force).

The weight of the pyramid is the same no matter how you place it. The force the pyramid puts on the scale will be the same and thus the sacale will give the same result.

Of course, if you have a device to measure pressure, the pyramid on its tip will show a much higher pressure, but the weight will be the same.

I know the weight would be the same, I just wondered if all measuring scales are that smart*

Based on other things than pressure, which seemed to be (in my mind) the logical way of measuring force. We oftern experience pressure as force in our daily lives. Well, that's my take on it. But never mind, thank you for the clarification.