Ppm

Simbolul ppm sau p/m (citit părți pe/per milion sau părți la milion) este un mod de exprimare a proporțiilor, de aceeași natură ca procentul și promila, dar folosit de obicei pentru fracțiuni foarte mici.[1] De exemplu, dacă despre concentrația masică a dioxidului de carbon din atmosferă se spune că este de 417 ppm, asta înseamnă că într-un milion de grame (o tonă) de aer se găsesc 417 grame de CO2; exprimată în procente, această concentrație este de 0,0417%, dar o asemenea notație este mai puțin intuitivă decît 417 ppm și permite mai greu comparațiile.

Proporțiile exprimate în ppm pot reprezenta concentrații sau titluri de aliaje (cît dintr-un amestec este o substanță), variații (cu cît crește sau scade în timp o mărime), stabilități (cu ce amplitudine fluctuează o mărime), erori de măsură (cu cît se abate valoarea măsurată de la cea reală) etc. Simbolul ppm este adimensional și reprezintă numărul 0,000001 = 10−6. De aceea, concentrațiile exprimate în ppm trebuie să reprezinte un raport de unități de același fel, ca grame, moli sau metri cubi. Pentru a exprima în ppm o concentrație definită ca raportul dintre masă și volum, aceasta trebuie mai întîi convertită în concentrație masică, ținînd cont de densitatea amestecului.

Sistemul internațional de unități nu recunoaște unitatea ppm, dar aceasta este folosită frecvent în știință și tehnologie.

Pentru proporții și mai mici decît ppm se folosește adesea unitatea similară ppb, părți pe miliard (din engleză: parts per billion): 1 ppb = 10−9.

Note

  1. ^ ppm, dexonline.ro
 Acest articol despre o unitate de măsură este un ciot. Puteți ajuta Wikipedia prin completarea lui !

Read other articles:

Margaret Gibson (pemeran)

Untuk kegunaan lain, lihat Margaret Gibson (disambiguation). Margaret GibsonGibson, 1917LahirElla Margaret Gibson(1894-09-14)14 September 1894Colorado Springs, Colorado, Amerika SerikatMeninggal21 Oktober 1964(1964-10-21) (umur 70)Hollywood, California, Amerika SerikatNama lainMargie Gibson Marguerite Gibson Helen Gibson Patricia Palmer Patsy Palmer Ella Margaret Arce Pat LewisTahun aktif1913–1929Suami/istriElbert Lewis (m.1935–1942, kematiannya) Ella Margaret Gibson (14 Se...

 

Aristobia

Aristobia Aristobia approximator Klasifikasi ilmiah Kerajaan: Animalia Filum: Arthropoda Kelas: Insecta Ordo: Coleoptera Famili: Cerambycidae Genus: Aristobia Aristobia adalah genus kumbang tanduk panjang yang tergolong famili Cerambycidae. Genus ini juga merupakan bagian dari ordo Coleoptera, kelas Insecta, filum Arthropoda, dan kingdom Animalia. Larva kumbang dalam genus ini biasanya mengebor ke dalam kayu dan dapat menyebabkan kerusakan pada batang kayu hidup atau kayu yang telah ditebang...

 

Lambang Kamerun

Lambang National Kamerun terdiri dari perisai dengan pita di atas dan di bawahnya. Di belakang perisai terdapat dua fases yang tersilang. Perisai ini memiliki warna yang sama dengan bendera Kamerun, dan di tengah terdapat peta negara tersebut. Di atas peta Kamerun terdapat timbangan. Pita di bawah bertuliskan nama resmi negara, dan hari kemerdekaannya. Pita di atas bertuliskan semboyan negara: Paix, Travail, Patrie. Fasces adalah lambang kekuasaan republik, dan timbangan melambangkan keadila...

Harrison Schmitt

American politician, astronaut and lunar explorer (born 1935) Harrison SchmittSchmitt in 1971United States Senatorfrom New MexicoIn officeJanuary 3, 1977 – January 3, 1983Preceded byJoseph MontoyaSucceeded byJeff Bingaman Personal detailsBornHarrison Hagan Schmitt (1935-07-03) July 3, 1935 (age 88)Santa Rita, New Mexico, U.S.Political partyRepublicanSpouseTeresa FitzgibbonEducationCalifornia Institute of Technology (BS)University of OsloHarvard University (PhD)AwardsNASA Disti...

 

Anagennisi Deryneia FC

Association football team in Deryneia, Cyprus Football clubAnagennisi DeryneiaFull nameAnagennisi DeryneiaGreek: Αναγέννηση ΔερύνειαςFounded1920; 104 years ago (1920)GroundAnagennisi Football GroundCapacity5,800ChairmanNicos LillisManagerPanayiotis KosmaLeagueThird Division2022–23Second Division, 14th (relegated) Home colours Away colours Anagennisi Deryneia (Greek: Αναγέννηση Δερύνειας) is Cypriot football team based in Deryneia, Fama...

 

هنود

هنودمعلومات عامةنسبة التسمية الهند التعداد الكليالتعداد قرابة 1.21 مليار[1][2]تعداد الهند عام 2011ق. 1.32 مليار[3]تقديرات عام 2017ق. 30.8 مليون[4]مناطق الوجود المميزةبلد الأصل الهند البلد الهند  الهند نيبال 4,000,000[5] الولايات المتحدة 3,982,398[6] الإمار...

Trarza Region

Region of Mauritania Region of MauritaniaTrarza ولاية الترارزةRegion of MauritaniaRosso TownMap of Mauritania showing Trarza RegionCoordinates: 17°59′N 14°44′W / 17.983°N 14.733°W / 17.983; -14.733Country MauritaniaDepartmentsBoutilimit, Keur Massene, Mederdra, Ouad Naga, R'Kiz, RossoCapitalRossoArea • Total67,800 km2 (26,200 sq mi)Population (2013)[1] • Total272,773 • Density4.0/...

 

Hertfordshire

County of England Not to be confused with Herefordshire. Ceremonial county in EnglandHertfordshireCeremonial countyKnebworth HouseGrand Union Canal in Berkhamsted, St Albans CathedralCoordinates: 51°49′N 0°13′W / 51.817°N 0.217°W / 51.817; -0.217Sovereign stateUnited KingdomConstituent countryEnglandRegionEastEstablishedLikely 10th centuryTime zoneUTC+0 (GMT) • Summer (DST)UTC+1 (BST)UK ParliamentList of MPsPoliceHertfordshire ConstabularyLargest to...

 

Club politique

Pour les articles homonymes, voir club. Si ce bandeau n'est plus pertinent, retirez-le. Cliquez ici pour en savoir plus. Cet article ne cite pas suffisamment ses sources (novembre 2013). Si vous disposez d'ouvrages ou d'articles de référence ou si vous connaissez des sites web de qualité traitant du thème abordé ici, merci de compléter l'article en donnant les références utiles à sa vérifiabilité et en les liant à la section « Notes et références ». En pratique ...

Counterfeit medications

False medication A counterfeit medication or a counterfeit drug is a medication or pharmaceutical item which is produced and sold with the intent to deceptively represent its origin, authenticity, or effectiveness. A counterfeit drug may contain inappropriate quantities of active ingredients, or none, may be improperly processed within the body (e.g., absorption by the body), may contain ingredients that are not on the label (which may or may not be harmful), or may be supplied with inaccurat...

 

The Peel Sessions (Siouxsie and the Banshees)

The Siouxsie and the Banshees Peel sessions are the first two sessions recorded by English post-punk band Siouxsie and the Banshees for John Peel's radio show on BBC Radio 1 in November 1977 and February 1978. First released in 1987 and 1988, both sessions were remastered to be included on the Voices on the Air: The Peel Sessions CD compilation. Releases The Peel Sessions EP (1987) The Peel SessionsEP by Siouxsie and the BansheesReleased24 February 1987Recorded29 November 1977GenrePunk, ...

 

Jazz in India

Indian music genre Tyagaraju known for his extensive contributions to Carnatic music. Music of India Genres Traditional Classical Carnatic Odissi Hindustani Folk Borgeet Baul Bhajan Kirtana Shyama Sangeet Ramprasadi Rabindra Sangeet Nazrul Geeti Dwijendrageeti Atulprasadi Prabhat Samgiita Thumri Dadra Chaiti Kajari Sufi Ghazal Qawwali Sikh Modern Bhangra Bhangragga Filmi Bollywood Ghazal Qawwali Goa trance Dance Indi-pop Asian Underground Jazz Rock Bengali Raga Hip hop Media and performance M...

Ijiranaide, Nagatoro-san

Ijiranaide, Nagatoro-sanSampul tankōbon volume 1, menampilkan Nagatoroイジらないで、長瀞さん(Ijiranaide, Nagatoro-san)GenreKomedi romantis MangaPengarangNanashiPenerbitKodanshaPenerbit bahasa InggrisNA VerticalImprintShonen Magazine ComicsMajalahMagazine PocketDemografiShōnenTerbit1 November 2017 – sekarangVolume19 (Daftar volume) AnimeSutradaraHirokazu HanaiSkenarioTaku KishimotoMusikGinStudioTelecom Animation FilmPelisensiCrunchyroll SEA MedialinkTayang 11 April 2021 – 27 J...

 

Attacchi missilistici su Gəncə del 2020

Attacchi missilistici su Gəncəparte della seconda guerra del Nagorno KarabakhData4 ottobre 2020, 8 ottobre 2020, 10 ottobre 2020, 17 ottobre 2020 LuogoGəncə TipoAttacco missilistico Forze in campoEseguito daHaykakan banak (forze armate armene) BilancioPerdite civili26 morti, 125 feriti voci di bombardamenti aerei presenti su Wikipedia Gli attacchi missilistici su Gəncə del 2020 (in azero: Gəncə bombalanmaları) comprendono quattro diversi attacchi missilistici compiuti contro la citt�...

 

Vantablack

Synthetic material, one of the darkest substances known For other uses, see Vantablack (disambiguation). Vantablack[1][2] Names Other names Activated carbon high density skeletonMultiwalled carbon nanotube (MWCNT)Vantablack S-VISVantablack S-IR Identifiers CAS Number 308068-56-6 Properties Chemical formula C Appearance Solid black coating Density 2.5 mg/cm3 Melting point >3,000 °C (5,430 °F; 3,270 K) Solubility in water Insoluble Hazards GHS labe...

Amatista

Para otros usos de este término, véanse Amatista (color) y Amatista, Princesa de Gemworld. Amatista GeneralCategoría MineralesClase SilicatosFórmula química SiO2Propiedades físicasColor Amatista (violeta en diversas tonalidades)Raya BlancaLustre Entre céreo y vítreoTransparencia Transparente a translúcidaSistema cristalino TrigonalHábito cristalino Prisma + romboedro, trapezoedro, bipirámideExfoliación NoFractura ConcoideaDureza 7Peso específico 2,65 constante; variable...

 

Black Voices for Trump

American political group Black Voices for TrumpTypeBlack conservatismTrumpismPurposeRaise political support for Donald TrumpMethodsCampaign events, merchandiseDirectorHarrison Floyd Black Voices for Trump was the official African American outreach effort of the Trump 2020 Campaign. Their goal was to raise support for former United States president Donald Trump among African Americans.[1][2][3] The group was founded in November 2019.[4][5] Activities The...

 

Parables of Jesus

Parables taught by Jesus of Nazareth according to Christian gospels The Parable of the Prodigal Son by keira Guercino, 1651 Events in theLife of Jesusaccording to the canonical gospels Early life Annunciation Visitation Joseph's dreams Nativity Virgin birth Annunciation to the Shepherds Adoration of the Shepherds Circumcision Adoration of the Magi Flight into Egypt Massacre of the Innocents Presentation Return to Nazareth Finding in the Temple Ministry Baptism Temptation Commissioning the Twe...

Verteidigungsetat

Der Verteidigungshaushalt, auch Verteidigungsbudget oder Verteidigungsetat (auch mit dem Präfix „Wehr-“ oder „Militär-“) genannt, umfasst alle Investitionen und Geldausgaben, die ein Staat über einen eingegrenzten Zeitraum hinweg für strategische Aktivposten tätigt. Erweiterte Definitionen erstrecken sich, neben den Verteidigungshaushalten der souveränen Staaten, auf die Militärausgaben derjenigen wenigen nichtstaatlichen politischen Akteure mit einem konstanten Zugriff auf fin...

 

Angular bone

This article relies largely or entirely on a single source. Relevant discussion may be found on the talk page. Please help improve this article by introducing citations to additional sources.Find sources: Angular bone – news · newspapers · books · scholar · JSTOR (April 2024) The angular is a large bone in the lower jaw (mandible) of amphibians and reptiles (birds included), which is connected to all other lower jaw bones: the dentary (which is the ent...