You do not have permission to edit this page, for the following reasons:

This IP address has been blocked from editing Wikipedia.
This does not affect your ability to read Wikipedia pages.
Most people who see this message have done nothing wrong. Some kinds of blocks restrict editing from specific service providers or telecom companies in response to recent abuse or vandalism, and can sometimes affect other users who are unrelated to that abuse. Review the information below for assistance if you do not believe that you have done anything wrong.

The IP address or range 44.201.0.0/16 has been blocked (disabled) by ‪ST47‬ for the following reason(s):

The IP address that you are currently using has been blocked because it is believed to be a web host provider. To prevent abuse, web hosts may be blocked from editing Wikipedia.
You will not be able to edit Wikipedia using a web host provider because it hides your IP address, much like a proxy or VPN.
We recommend that you attempt to use another connection to edit. For example, if you use a proxy or VPN to connect to the internet, turn it off when editing Wikipedia. If you edit using a mobile connection, try using a Wi-Fi connection, and vice versa. If you are using a corporate internet connection, switch to a different Wi-Fi network. If you have a Wikipedia account, please log in.
If you do not have any other way to edit Wikipedia, you will need to request an IP block exemption.

How to appeal if you are confident that your connection does not use a web host's IP address:
If you are confident that you are not using a web host, you may appeal this block by adding the following text on your talk page: ((unblock|reason=Caught by a web host block but this host or IP is not a web host. My IP address is _______. Place any further information here. ~~~~)). You must fill in the blank with your IP address for this block to be investigated. Your IP address can be determined here. Alternatively, if you wish to keep your IP address private you can use the unblock ticket request system. There are several reasons you might be editing using the IP address of a web host (such as if you are using VPN software or a business network); please use this method of appeal only if you think your IP address is in fact not a web host.

Administrators: The IP block exemption user right should only be applied to allow users to edit using web host in exceptional circumstances, and they should usually be directed to the functionaries team via email. If you intend to give the IPBE user right, a CheckUser needs to take a look at the account. This can be requested most easily at SPI Quick Checkuser Requests. Unblocking an IP or IP range with this template is highly discouraged without at least contacting the blocking administrator.

This block will expire on 23:54, 31 July 2024.

Even when blocked, you will usually still be able to edit your user talk page, as well as email administrators and other editors.

For information on how to proceed, please read the FAQ for blocked users and the guideline on block appeals. The guide to appealing blocks may also be helpful.

Other useful links: Blocking policy · Help:I have been blocked
Your IP address is in a range that has been blocked on all Wikimedia Foundation wikis. The block was made by ‪AntiCompositeNumber‬. The reason given is Open proxy/Webhost: Visit the FAQ if you are affected .
- Start of block: 13:55, 18 August 2022
- Expiry of block: 13:55, 18 April 2025
Your current IP address is 44.201.28.123. The blocked range is 44.201.0.0/16. Please include all above details in any queries you make. If you believe you were blocked by mistake, you can find additional information and instructions in the No open proxies global policy. Otherwise, to discuss the block please post a request for review on Meta-Wiki. You could also send an email to the stewards VRT queue at stewards@wikimedia.org including all above details.

You can view and copy the source of this page:

((short description|Instrument that measures friction and wear between surfaces))
((Refimprove|date=April 2010))
[[File:NANOVEA T100 Advanced Pneumatic Tribometer.jpg|thumb|335x335px|Pneumatic tribometer]]
[[File:6.02 Static Friction Tribometer.jpg|thumb|Static Friction Tribometer|373x373px]]
[[File:Argonne's Tribology Lab - Hydrogen Tribometer.jpg|thumb|Hydrogen Tribometer|334x334px]]

A '''tribometer''' is an instrument that measures [[Tribology|tribological]] quantities, such as [[coefficient of friction]], friction force, and [[wear]] volume, between two surfaces in contact. It was invented by the 18th century [[Netherlands|Dutch]] scientist [[Pieter van Musschenbroek|Musschenbroek]]<ref>[https://books.google.com/books?id=RUQZPb4q-tkC&pg=PA210 Historic scientific instruments in Denmark]</ref><ref>Hutton, Charles [http://archimedes.mpiwg-berlin.mpg.de/cgi-bin/archim/dict/hw?lemma=TRIBOMETER&step=entry&id=d006 A Mathematical and Philosophical Dictionary] ((Webarchive|url=https://web.archive.org/web/20110926233003/http://archimedes.mpiwg-berlin.mpg.de/cgi-bin/archim/dict/hw?lemma=TRIBOMETER&step=entry&id=d006 |date=2011-09-26 ))</ref>

A '''tribotester''' is the general name given to a machine or device used to perform tests and simulations of wear, friction and [[lubrication]] which are the subject of the study of tribology.((Citation needed|date=March 2018|reason=unclear if statement is based on widely-accepted definition. source should be stated.)) Often tribotesters are extremely specific in their function and are fabricated by manufacturers who desire to test and analyze the long-term performance of their products. An example is that of [[Implant (medicine)|orthopedic implant]] manufacturers who have spent considerable sums of money to develop tribotesters that accurately reproduce the motions and forces that occur in human [[hip joint]]s so that they can perform accelerated wear tests of their products.

==Theory==
[[Image:Pulley diagram.svg|thumb|334x334px]]

A simple tribometer is described by a hanging mass and a mass resting on a horizontal surface, connected to each other via a string and pulley. The [[coefficient of friction]], ''µ'', when the system is stationary, is determined by increasing the hanging mass until the moment that the resting mass begins to slide. Then using the general equation for friction force:
:<math>F = \mu N</math>

Where ''N'', the normal force, is equal to the weight (mass x gravity) of the sitting mass (''m''<sub>T</sub>) and ''F'', the loading force, is equal to the weight (mass x gravity) of the hanging mass (''m''<sub>H</sub>).

To determine the kinetic coefficient of friction the hanging mass is increased or decreased until the mass system moves at a constant speed.

In both cases, the coefficient of friction is simplified to the ratio of the two masses:
:<math>\mu\ = m_H / m_T</math>

In most test applications using tribometers, wear is measured by comparing the mass or surfaces of test specimens before and after testing. Equipment and methods used to examine the worn surfaces include [[optical microscope]]s, [[scanning electron microscope]]s, [[optical interferometry]] and mechanical roughness testers.

==Types==
Tribometers are often referred to by the specific contact arrangement they simulate or by the original equipment developer. Several arrangements are:
* Four ball <ref>((cite journal
|title=Evaluation of Several Space Lubricants Using a Vacuum Four-Ball Tribometer 
|journal=Tribology Transactions
|volume=42
|issue=2
|pages=317–323
|doi=10.1080/10402009908982223
|year=1999
|last1=Jones
|first1=William R.
|last2=Poslowski
|first2=Agnieszka K.
|last3=Shogrin
|first3=Bradley A.
|last4=Herrera-Fierro
|first4=Pilar
|last5=Jansen
|first5=Mark J.
|hdl=2060/19990013975
|s2cid=137361318
|hdl-access=free
))</ref>
* Pin on disc
* Ball on disc
* Ring on ring
* Ball on three plates
* Reciprocating pin (usually referred to as ''SRV or HFRR'') <ref>((Cite journal|last1=Wei|first1=D.P.|last2=Spikes|first2=H.A.|last3=Korcek|first3=S.|date=1999|title=The Lubricity of Gasoline|journal=Tribology Transactions|volume=42|issue=4|pages=813–823|doi=10.1080/10402009908982288))</ref>
* Block on ring
* Bouncing ball <ref>((Cite journal
  | last1 = Höglund  | first1 = Erik
  | title = The Relationship Between Lubricant Shear Strength and Chemical Composition of the Base Oil
  | journal = Wear
  | volume = 130
  | pages = 213–224
  | date = March 1989
  | doi=10.1016/0043-1648(89)90234-2
  ))
</ref>
* Fretting test machine
* Twin disc

===Bouncing ball===
A ''[[bouncing ball]] tribometer'' consists of a ball which is impacted at an angle against a surface. During a typical test, a ball is slid on an angle along a track until it impacts a surface and then bounces off of the surface. The friction produced in the contact between the ball and the surface results in a horizontal force on the surface and a rotational force on the ball. Frictional force is determined by finding the rotational speed of the ball using high speed photography or by measuring the force on the horizontal surface. Pressure in the contact is very high due to the large instantaneous force caused by the impact with the ball.

''Bouncing ball'' tribometers have been used to determine the shear characteristics of lubricants under high pressures such as is found in [[ball bearings]] or [[gears]].

===Pin on disc===
A ''pin on disc tribometer'' consists of a stationary pin that is normally loaded against a rotating disc. The pin can have any shape to simulate a specific contact, but cylindrical tips are often used to simplify the contact geometry. The coefficient of friction is determined by the ratio of the frictional force to the loading force on the pin.

The pin on disc test has proved useful in providing a simple wear and friction test for low friction [[coatings]] such as [[diamond-like carbon]] coatings on [[valve train]] components in [[internal combustion engine]]s.

== See also ==
* [[Abrasion (mechanical)|Abrasion]]
* [[Twist compression tester]]
* [[Tribology]]

==References==
((Reflist))


[[Category:Tribology]]
[[Category:Measuring instruments]]
[[Category:Materials science]]

Pages transcluded onto the current version of this page (help):

Tribometer (edit)
Template:Ambox (view source) (template editor protected)
Template:Category handler (view source) (protected)
Template:Citation needed (view source) (protected)
Template:Cite journal (view source) (protected)
Template:Delink (view source) (protected)
Template:Find sources mainspace (view source) (template editor protected)
Template:Fix (view source) (protected)
Template:Fix/category (view source) (protected)
Template:Main other (view source) (protected)
Template:More citations needed (view source) (template editor protected)
Template:Pagetype (view source) (protected)
Template:Refimprove (view source) (template editor protected)
Template:Reflist (view source) (protected)
Template:Reflist/styles.css (view source) (protected)
Template:SDcat (view source) (protected)
Template:Short description (view source) (protected)
Template:Short description/lowercasecheck (view source) (protected)
Template:Webarchive (view source) (template editor protected)
Module:Arguments (view source) (protected)
Module:Category handler (view source) (protected)
Module:Category handler/blacklist (view source) (protected)
Module:Category handler/config (view source) (protected)
Module:Category handler/data (view source) (protected)
Module:Category handler/shared (view source) (protected)
Module:Check for unknown parameters (view source) (protected)
Module:Citation/CS1 (view source) (protected)
Module:Citation/CS1/COinS (view source) (protected)
Module:Citation/CS1/Configuration (view source) (protected)
Module:Citation/CS1/Date validation (view source) (protected)
Module:Citation/CS1/Identifiers (view source) (protected)
Module:Citation/CS1/Utilities (view source) (protected)
Module:Citation/CS1/Whitelist (view source) (protected)
Module:Citation/CS1/styles.css (view source) (protected)
Module:Delink (view source) (protected)
Module:Disambiguation/templates (view source) (protected)
Module:Find sources (view source) (template editor protected)
Module:Find sources/config (view source) (template editor protected)
Module:Find sources/links (view source) (template editor protected)
Module:Find sources/templates/Find sources mainspace (view source) (template editor protected)
Module:Message box (view source) (protected)
Module:Message box/ambox.css (view source) (protected)
Module:Message box/configuration (view source) (protected)
Module:Namespace detect/config (view source) (protected)
Module:Namespace detect/data (view source) (protected)
Module:Pagetype (view source) (protected)
Module:Pagetype/config (view source) (protected)
Module:Pagetype/disambiguation (view source) (protected)
Module:Pagetype/setindex (view source) (protected)
Module:Pagetype/softredirect (view source) (protected)
Module:SDcat (view source) (protected)
Module:String (view source) (protected)
Module:Unsubst (view source) (protected)
Module:Webarchive (view source) (template editor protected)
Module:Webarchive/data (view source) (template editor protected)
Module:Wikitext Parsing (view source) (protected)
Module:Yesno (view source) (protected)

Return to Tribometer.

Retrieved from "https://en.wikipedia.org/wiki/Tribometer"