Skip to main content
44 votes

How can I measure correctly with a ruler?

For this answer, I'll be using this terrible excuse of a ruler, where is the lines indicating each millimeter and the . is ...
Wasabi's user avatar
  • 13.1k
28 votes

How can I measure correctly with a ruler?

You should include the thickness of one total line. In an ideal world, one would measure the the centre of each line (marked 'also correct' below). In this case, you're including half of each line. It'...
Jonathan R Swift's user avatar
21 votes
Accepted

What unit of weight is that?

You are probably right (it being of Russian origin). The weight seems to be 5 funt. 1 funt is the Russian equivalent of a pound. It is written as Фунт, funt, and around 1900 it was the basic unit of ...
NMech's user avatar
  • 24.3k
9 votes
Accepted

What is the "tl" unit of weight measurement?

It could be a tola. 1 tola = 3/8 troy ounce (exactly) = 11.66g (approx.), so 10g = 0.857 tolas. If the scale has an accuracy of 0.01g (it's not very clear from the ebay description!) that would be ...
alephzero's user avatar
  • 12.5k
7 votes

Seeing through walls and noninvasive structural integrity metrics

Depending on the region and structure of building the techniques might vary. Below are few suggestions Termite inspection is another popular method to determine the structure integrity of building. ...
Mahendra Gunawardena's user avatar
7 votes
Accepted

Units to use in this formula?

You can use any consistent set of units. That includes SI. But if you try to use a pressure in ATM, a sphere radius in feet, a wall thickness in mils, and want the stress in tons per square inch, you ...
alephzero's user avatar
  • 12.5k
6 votes

Can we build a tool that measure curvature on an arc?

For a circle, yes. Such a tool exists: Digital Radius Caliper There are also Digital Radius Gauges, which may be useful for smaller curves. For a general curve, you can't measure the curvature ...
atom44's user avatar
  • 2,641
6 votes

What does 12 bit resolution mean?

With 12-bit resolution, $2^{12}= 4096$ different numbers can be represented, this means that the measuring range of a given sensor gets split into 4096 pieces. As an example, if your sensor can ...
OpticalResonator's user avatar
6 votes
Accepted

Measuring a pattern size on a flat surface

I had a plastic ruler at one time in my life and it looked something like Figure 1. Figure 1. Overview. Figure 2. Close up of precision grid. Figure 3. In-use. How to use: Align the right edge to ...
Transistor's user avatar
  • 10.8k
5 votes

What is the difference between tolerance and uncertainty in measurement?

Tolerance is a property of a design. Tolerance is a acceptable deviation from plan that is designed as part of your acceptance criteria. You document this in your drawing/contract either as a general ...
joojaa's user avatar
  • 3,577
5 votes

Are there different Gauge standards out there?

Gage (gauge) thickness are somewhat arbitrary. Take for example the table below, excerpted from the AISC Steel Construction Manual, 14th Ed.: You can see that gage thicknesses vary depending on ...
grfrazee's user avatar
  • 3,587
5 votes

Distance sensors with accuracy of 1 mm?

Was looking for other distance solutions, and came across this question. A sensor that I've found works well is the Sharp GP2Y0E02B (digital version) (newer version is the GP2Y0E03). Configuring it ...
asylumax's user avatar
  • 181
5 votes
Accepted

How to convert Square FT (in.) to Square FT (ft)?

Let's think about how we work out the area in inches. What we are simply doing is multiplying the lengths (in inches) of the shape (let's say rectangle for simplicity) to get the square footage. ie. ...
Ronikos's user avatar
  • 166
5 votes
Accepted

What is the engineering standard for filenames with fractions and inches?

I've seen numerous formats in my experience. Per some of the comments, sometimes you'll see a fraction represented with dashes, underscores, or as a decimal. I find that most often, decimals are ...
GisMofx's user avatar
  • 1,578
5 votes

Confused as to how to read this caliper

The problem with most analog meters and measuring devices is you have no feedback on your reading to confirm you are correct. Metric vernier caliper, (calliper or pachymeter), read in millimeter and ...
StainlessSteelRat's user avatar
5 votes

How can I measure correctly with a ruler?

In theory I agree with others, what's important here is consistency, exact values are meant to be at the center of the lines (so measure center to center or maybe easier from left side to left side). ...
Máté Juhász's user avatar
4 votes
Accepted

How does a frequency to voltage converter work?

There are a number of ways. As Russell described, one way is to make a fixed size pulse each period, then low pass filter the result. Another is to make a frequency-dependent filter. Feed in a ...
Olin Lathrop's user avatar
  • 11.4k
4 votes

Can we build a tool that measure curvature on an arc?

How about a Contour Gauge: And here: Wikipedia Article Make your measurement Trace it Scan/digititize it Analyze it (spline/curve fit) with some type of CAD software.
GisMofx's user avatar
  • 1,578
4 votes
Accepted

How were 90 degree angles made?

Perpendicularity can be achieved by using any item of constant length. Knotted cord was used by the Greeks, Romans, and Ancient Egyptians. Sticks work well too. The simplest way to establish ...
ericnutsch's user avatar
  • 8,151
4 votes
Accepted

How can I accurately measure the actuation force of small buttons (<1cm diameter) using home equipment?

If you want a quick and somewhat inaccurate hill-billy engineering answer, I would take a digital kitchen scale and place the PSV ontop of it, tare it, then load up a program to test the buttons (game,...
Jason's user avatar
  • 165
4 votes

Making precise, intricate measurements

A relatively inexpensive and quite useful device would be a "pocket optical comparator". They come with Several etched glass plates with features of size that you optically/visually compare to your ...
GisMofx's user avatar
  • 1,578
4 votes
Accepted

How can I detect black spots?

The simplest method will be a multi-step approach. The first step will be a defective product detection, that gathers general data about the product stream and quarantines defective products. On a ...
Mark's user avatar
  • 5,333
4 votes

Would connecting 100's of small telescopes into one huge telescope make for a significantly better telescope?

There are two issues here, noise and resolution. Combining the optical images from multiple telescopes would reduce the overall noise. This is because each image is independent of the others, so all ...
Olin Lathrop's user avatar
  • 11.4k
4 votes
Accepted

What device would you use to set angles in two plates?

Although a photo or diagram or more detailed description would be helpful, you may find what you seek in a machinist's protractor. There are a few different designs, including a few electronic digital ...
fred_dot_u's user avatar
  • 7,132
4 votes

Mechanism for controlling the clamping force

The bicycle disk as shown is inherently prone to shimmying and spiraling into an increasing flutter. I have an Ebike with a very similar disk brake and I have learned my lesson to be cautious with it. ...
kamran's user avatar
  • 22.4k
4 votes

Measuring axial force in trapezoidal screw jack

(Other supports compliant) I thought, that if you had an assembly and were straightening out a cantilever portion, you could fix the jack screw and make the other supports compliant. Such as ...
Jim Clark's user avatar
  • 496
3 votes
Accepted

Determine volume of liquid in a fluid bladder

Here are some options: Weight- Reliable if the density is known. Bladder can be hung from a load cell, or placed on a surface supported by load cells, and volume can be derived continuously. Bag in ...
ericnutsch's user avatar
  • 8,151
3 votes

How can I calculate the evaporation rate for a hazmat spill?

The evaporation formula you have is a modification of the EPA method for calculating the evaporation rate. See here: Technical Guidance for Hazards Analysis look at Appendix G. The modified form I ...
Salomon Turgman's user avatar
3 votes

How to regulate a vacuum pump?

The device you're looking for is called a vacuum regulator and sits between the vacuum source and the process. This page from Equilibar shows some examples and provides links that explain how they ...
DLS3141's user avatar
  • 2,145
3 votes

Measuring the road surface quality

While the acoustic analysis idea may* work, I think the accellerometer data would be much easier to analyze. If you are looking for something that can give you better rates of data, try looking into ...
ambitiose_sed_ineptum's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible