Measuring Tools

First calibrate the micrometer by dialing the spindle to zero and adjusting the anvil until it is flush against the spindle. Measure the screw until the ratchet begins to click and take the first reading. This reading can then be compared to a machining book to verify the pitch diameter.

Small physical size when tape is rolled up - most are 5 meters or more long, 5 meters of cord is a big pile. A tape measure is stiff, a cord will stretch so accuracy is better, you can hook the end of a tape measure over it, walk all the way to the end to measure, a cord you would have to fit it (nail/tape) at one end first, so ease of use.

Gn (sometimes Gr) is a very old unit of measurement called "Grains".

It is based on the approximate weight of a single grain of wheat (or other cereal).

Grains is the unit of measurement traditionally used in Apothecaries.

In more recent times, Grains has been used to measure gunpowder.

1 Grain = 0.0648 grams

1 Grain = 0.0023 ounces

A footstep bearing is essentially a cast-iron block with a gunmetal bush that has a hollow collar fitted on its top. This bearing is used to keep the shaft upright in a vertical position. The shaft is fixed in place and not allowed to rotate by a pin.

a rule has a different name then a ruler

the instrument can be made more sensitive by making vernier constant less ie by incresing the no of division on vernier scale or by decreasing the value of main scale.

Caliper is a simple measure that the two jaws and a ruler is correct.

Precision caliper 1 / 128 inch is.

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A Vernier Caliper, and the digital, non-vernier, equivalent, measures to 1/1000", much finer than 1/128".

Engineering measurement tolerances are the permissible limits of variation in measurements. Example a piece of steel 25mm square where it would be allowed to be +.001mm or -.001mm on this size. The plus or minus is the tolerance

Quantitative Data is only as good as the following:

1)The accuracy of the tools or machines used to measure whatever it is that is obtaining the data. For example, one of the reasons that the calipers to measure bolts for spacecrafts cost the huge amounts we all laugh about is not a laughing matter. The required precision is so high it is not the same as the precision that one might need for a school project!

2) Human error. Somebody is doing the measurements or adding reagents if it is an experiment, and so on. For example, someone came to my home to test the water. They had a type of device that could measure how much color was caused by a reagent added to water. Sounds good right? Not so right. The people did not know how to add water correctly to a test tube so that the correct amount of water mixed with the correct amount of reagent!

3) Computer error. Don't think it does not happen!

Despite the drawbacks, overall quantitative data is generally BETTER than qualitative, but it is not perfect. Remeber Apollo 13!

main scale is the least accurate reading on the device. the vernier scale uses an offset of divions that only allows one "line" or division to line up with the scale below. This scale is more accurate than the main scale. for example, the main scale may produce an accuracy of 0.125 of and inch plus or minus 0.125 of an inch, whereas the vernier would produce an accuracy of 0.025 of and inch. therefore if two divivions of the main scale and one division of the vernier scale were combined it would prodice and reading of (0.125+0.125+0.025 = 0.275) inches.

Pressurized oxygen can be very dangerous and pose a hazard of explosion when exposed to heat sources, unlike other common compressed gasses such as nitrogen and carbon dioxide. The less pressurized the oxygen is, the smaller the risk of this happenning. Filling a tank to the gauge minimum instead of the maximum allowable mitigates risk to anyone who may be around it.

A battery hydrometer which measures the specific gravity (relative density) of liquids, to determine the concentration of sulfuric acid in each cell.

stubby 18mm wrench and a hammer

For surveying, there are some use of tools. Look at them, The Dividing Engine, Chains, Calculating device (non electric), leveling machine , strange and some other. These tools are very unique to use.

Former i.e. Vernier Caliper

1/no of disions in 1cm of main scale.

1 micro meter or 1 millionth of a meter or 1/1000 th of a millimeter - so pretty small

A "screw pitch gauge" is used to measure screw pitch. Typically, the gauge has a number of indented templates for each standard pitch. Matching a particular template to the screw or nut gives the pitch.

You can also use a measuring device (ruler, micrometer, etc.) to measure a group of threads and then "do the math" to estimate pitch. Accuracy depends on your ability to accurately measure length and count threads.

One type of compass is a magnetic or electronic device that shows the cardinal directions by indicating North (Magnetic or True). It is used for finding directions.

Another type of compass can also be known as "dividers", depending on whether or not they contain a pencil. They look like two sticks joined together at one end with a hinge. This allows the points of the sticks to spread or close. This device is used to measure distances on maps or charts & for plotting courses. The type with a pencil is used for drawing circles.

See the Related Link(s) listed below for more information:

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A compass (singular) is used to find direction and location (the latter by plotting intersecting bearings on the map).

[A pair of] compasses (plural) is not the same as dividers. Compasses have a pencil or pen for drawing circles & arcs; dividers have two sharp steel points.

I would use grams, although i have heard both terms used. Hope you find out!