What is a micrometer?
A micrometer, also known as a Palmer screw, is a length measuring instrument in the metric system that is equivalent to one millionth of a meter, that is, 0.000001 meters. It is also known as micron or micron. The symbol for the micrometer is "µm," where the symbol "µ" is called "mu" and represents the prefix "micro," which denotes a scale of one million.
The micrometer is commonly used in science, technology and industry to measure extremely small distances, especially in the field of microscopy, nanotechnology and metrology. For example, the size of individual cells, microscopic particles, and features of electronic devices is often measured in micrometers.
Importantly, the micrometer is one of the smallest units of measurement in the metric system and is used to describe lengths on a microscopic scale. To give you an idea of their size, a typical human hair has a diameter of around 50 to 100 micrometers, and human cells can range in size from a few microns to more than 100 micrometers, depending on the type of cell.
In short, a micrometer is a unit of length measurement used to describe extremely small distances, being one millionth of a meter or 0.000001 meters.
Micrometer Parts
The main parts of a micrometer are the following:
- Body: The body of the micrometer is a generally metal piece that has a cylindrical or similar shape. At one end of the body is the opening through which the object to be measured is introduced.
- Spindle: The spindle is a finely threaded screw that slides along the body of the micrometer. The end of the spindle has a tip that makes contact with the object to be measured.
- Drum: The drum is a graduated toothed wheel located at the top of the micrometer. It has marks and scales that allow the measurement to be read with great precision.
- Vernier or vernier: In some micrometers, especially vernier micrometers, there is an additional scale called a vernier or vernier, which allows for an even more precise measurement.
- Housing or frame: The micrometer housing is the external part that protects and covers the internal parts of the instrument. In some modern micrometers, the housing may be plastic to reduce weight and facilitate handling.
- Ratchet: Some micrometers include a ratchet that emits a sound or tactile sensation when the proper pressure is applied when measuring an object, helping to avoid applying too much force and damaging the part being measured.
- Ratchet lever: The ratchet lever is a lever or button that allows you to adjust the pressure applied to the object being measured.
The operation of the micrometer is based on the rotation of the spindle to measure the size of the object. The distance that the spindle travels is measured with the scale on the drum and, in some cases, with the help of the vernier. Measurements are read in units of length, such as millimeters or inches, and are expressed with high precision, often down to hundredths or thousandths of a unit, depending on the micrometer in question.
Proper use of the micrometer requires precise and careful technique to obtain accurate measurements.
How does a micrometer work?
To make a measurement with a micrometer, you have 2 ends that join each other by means of a fine-thread screw, it contains the measurement scale written, in some cases the measurement scale may include a vernier. In order to block the displacement of the screw, there is a fixing nut. The maximum length of a standard outside category micrometer is 25 millimeters. The micrometer that is most used today to make these measurements is digital.
types of micrometers
There are several types of micrometers on the market today depending on the shape and type of measurement you use.
Depending on the type of measurement, there are three types:
depth micrometer
It is used to measure depths, it is a micrometer that consists of a mobile axis with a threaded part, at the end of which a graduated drum is mounted, producing turns in the graduated drum, the movement of the micrometric screw is achieved, and therefore the mobile axis. , which will stop moving only by touching the part we are measuring.
outside micrometer
This micrometer is used to make high-precision measurements, they are widely used at the business and industrial level, the size and dimensions of this instrument vary depending on the range of measurements that are going to be used. An example for which this type of micrometer would be used would be a thin metal rod.
inside micrometer
This type of micrometer is used to measure the interior areas of an object, for example the diameters of the holes in the interior part of an object. It contains a millimeter head to be able to add one or more extension shafts.
These are the types of micrometers that exist, but depending on the way of reading we can find 3 different types: Digital, dial or analog.
Digital Micrometer
It is used to make length measurements between its two measurement contacts. It is a direct measurement system and consists of a part with a fixed stop and another mobile type that has a micrometric head. Unlike conventional micrometers that require manual scale readings, the digital micrometer uses a digital display to display the measurement numerically. This makes the measurement more accurate and easier to read.
Common features of a digital micrometer include:
- Digital screen: Instead of a graduated scale and vernier caliper, a digital micrometer has a screen that shows the measurement with an exact number. This eliminates subjective reading errors and allows for fast and accurate reading.
- Zero buttons: Digital micrometers usually have "zero" buttons that allow the device to be calibrated to measure differences or tolerances from a reference point.
- Retention functions: Some models have a hold feature that allows you to lock the measurement on the screen, making it easier to read when working in hard-to-reach areas.
- Unit conversion: Many digital micrometers allow you to switch between different units of measurement, such as micrometers (μm), millimeters (mm), inches (in), and more.
- Auto power off: To conserve battery life, some digital micrometers have an automatic power-off feature that turns them off after a period of inactivity.
Digital micrometers are widely used in various industries such as manufacturing, engineering, metrology and quality inspection due to their accuracy and ease of use. They are also useful when you need to measure small-sized objects or detailed features with high precision. Digital reading eliminates human errors that could occur when interpreting a graduated scale, making the results more reliable.
Dial Micrometer
It converts linear movements of a movable spindle into circular movements of a pointer. They are often used to compare measurements and perform checks of various kinds.
Analog Micrometer
They consist of a sphere with a needle that will mark the measurement, this type of micrometers are used more for day-to-day checks since they are not as precise as digital ones, for example.
In this article we have described what a micrometer is and what are the different types that there are, we must also differentiate micrometers according to different criteria.
How to measure with a micrometer
- If, for example, we want to measure the face of a watch, the piece must be held between the spindle and the anvil.
- When the sphere is completely clamped between the 2 parts we have to continue turning the ratchet knob and then we have to hear three clicks.
- Next we fix the measurement of the nut turning the brake while the anvil and the spindle hold the piece that we are going to carry out the measurement.
- Finally, we remove the piece from the micrometer with the brake already locked and we will have already obtained the measurement of the piece in question.
To finish we leave you an explanatory video talking about what we have written in this article talking about the micrometer:
If you want to know a similar instrument called caliper vernier visit our article.
