Daidaitaccen yanayin nasarar
Daidaitaccen yanayi (alama: atm ) naúrar matsa lamba ce da aka ayyana a matsayin 101325 Pa . Wani lokaci ana amfani da shi azaman matsi na tunani ko daidaitaccen matsi . Yana da kusan daidai da matsakaicin matsakaicin yanayin yanayi a matakin teku.

Tarihi 
An kwatanta daidaitaccen yanayi a asali azaman matsin lamba da ginshiƙin mercury na 760 mm ya yi a  da daidaitaccen nauyi ( g n = 9.80665 m/s 2 ). An yi amfani da shi azaman yanayin tunani don kaddarorin jiki da sinadarai, kuma yana cikin ma'anar ma'aunin zafin jiki na Celsius, wanda ya ayyana  a matsayin wurin tafasar ruwa a wannan matsi. A cikin 1954, Babban Taro na 10 akan Ma'auni da Ma'auni (CGPM) ya karɓi daidaitaccen yanayi don amfanin gabaɗaya kuma ya tabbatar da ma'anarsa na kasancewa daidai da 1013 250 dynes a kowace murabba'in santimita ( 101325) . ba ).  Wannan ya ayyana matsi ta hanyar da ta kasance mai zaman kanta daga kaddarorin kowane abu na musamman. Bugu da ƙari, CGPM ya lura cewa an sami wasu rashin fahimta cewa ma'anar da ta gabata (daga 9th CGPM) "ya jagoranci wasu masana kimiyya suyi imani cewa wannan ma'anar daidaitattun yanayi yana aiki ne kawai don ingantaccen aiki a cikin thermometry ." 

A cikin ilmin sunadarai da kuma a cikin masana'antu daban-daban, matsin lamba da ake magana a kai a daidaitaccen zafin jiki da matsa lamba ya kasance  kafin 1982, amma matakan sun bambanta; a cikin 1982, International Union of Pure and Applied Chemistry ya ba da shawarar cewa don dalilai na tantance kaddarorin abubuwa na zahiri, matsa lamba daidai ya kamata ya zama daidai  .

Raka'a matsi da daidaitattun daidaito 
A matsa lamba na 1 Atm kuma za a iya bayyana kamar haka:

 ≡ 101325 pascals (Pa)
 ≡ 1.01325 bar
 ≈ 1.033 kgf /cm 2
 ≈ 1.033 fasaha yanayi
 ≈ 10.33 m H 2 O, 4 °C 

 ≈ 760 mmHg, 0 °C, ƙarƙashin bita yayin da ƙarin ma'aunin ma'auni na mercury ke samuwa  
 ≡ 760 torr (Torr) 
 ≈ 29.92 inHg, 0 °C, ƙarƙashin bita yayin da ƙarin ma'aunin ma'auni na mercury ke samuwa  

 ≈ 406.782 a cikin H 2 O, 4 ° C 
 ≈ 14.6959 fam-ƙarfi a kowane inci murabba'i (lbf/a cikin 2 )
 ≈ 2116 .22 fam-ƙarfi a kowace ƙafar murabba'in (lbf/ft 2 )
 = 1 ata (yanayin cikakke).

Ana amfani da naúrar ata a wuri na atm don nuna jimlar matsa lamba na tsarin, idan aka kwatanta da vacuum.  Misali, matsa lamba na karkashin ruwa na 3 ata yana nufin cewa wannan matsa lamba ya ƙunshi 1 atom na iska kuma don haka 2 atm saboda ruwa.

Bayanan kula 
Wannan ita ce ƙimar da aka saba yarda da ita don cm-H2O, 4 °C. Yana da daidai samfurin 1 kg-ƙarfi a kowace murabba'in santimita (yanayin fasaha ɗaya) sau 1.013 25 (bar / yanayi) zuwa kashi 0.980 665 (ƙarfin gram ɗaya). Ba a yarda da aikin ba don ayyana ƙimar ginshiƙin ruwa dangane da ainihin fahimtar ruwa ta zahiri (wanda zai zama 99.997 495% na wannan ƙimar saboda ainihin matsakaicin ƙimar Vienna Standard Mean Water Water shine 0.999 974 95 kg/L a 3.984). °C). Hakanan, wannan "ganewar jiki" har yanzu zai yi watsi da raguwar 8.285 cm–H2O wanda zai faru a zahiri a zahirin zahirin zahiri saboda matsa lamba akan ruwa a 3.984 °C. Ƙimar NIST na 13.595 078(5) g/mL da aka ɗauka don yawan Hg a 0 °C Torr da mm-Hg, 0°C galibi ana ɗauka su zama iri ɗaya. Don yawancin dalilai masu amfani (zuwa mahimman lambobi 5), ana iya musanya su.

Duba kuma 

 Standard temperature and pressure
 Atmospheric pressure
 International Standard Atmosphere

Manazarta