Komen Ekipman ak Seleksyon Principles of Multimeters
The digital multimeter is currently the most commonly used digital instrument. Its main characteristics are high accuracy, strong resolution, complete testing functions, fast measurement speed, intuitive display, strong filtering ability, low power consumption, and easy to carry. Since the 1990s, digital multimeter has been rapidly popularized and widely used in China, becoming an essential instrument for modern electronic measurement and maintenance work, and gradually replacing traditional analog (i.e. pointer) multimeter.
Digital multimeter, tou li te ye kòm digital Multimeter (DMM), gen a lajè varyete nan modèl. Chak elektwonik travayè espere hospes gen yon ideyal dijital multimeter. Gen anpil prensip pou chwazi yon digital multimeter, ak pafwa yo varye soti nan moun moun. Men pou handheld (pòch) digital multimeter, li ta dwe gen karakteristik yo klè ekspozisyon, segondè presizyon, fò rezolisyon, lajè tès ranje ranje tès tès fonksyon fonksyon, fò anti-entèferans kapasite abilite, relativman konplè pwoteksyon sikwi bèl aparans, jenere aparans, fasil operasyon, fleksibilite, fyabilite, low pouvwa konsomasyon% portability portability, abòdab pri% 2c ak konsa sou.
The main indicators, montre chif yo, ak ekspozisyon karakteristik a digital multimeter
The display digits of a digital multimeter are usually {{0}}/2 to 8 1/2 digits. There are two principles for determining the display digits of a digital instrument: firstly, the digits that can display all digits from 0 to 9 are integer digits; The second is that the numerical value of the fractional digit is based on the highest digit in the maximum displayed value as the numerator, and when measuring at full scale, the value is 2000. This indicates that the instrument has 3 integer digits, while the numerator of the decimal digit is 1 and the denominator is 2, so it is called 3 1/2 digits, pronounced as "three and a half digits". Its highest digit can only display 0 or 1 (0 is usually not displayed). The highest digit of a 32/3 digit (pronounced as "three and two-thirds digits") digital multimeter can only display numbers ranging from 0 to 2, so the maximum display value is ± 2999. In the same situation, it is 50% higher than the limit of a 3 1/2 digit digital multimeter, especially valuable for measuring 380V AC voltage.
Popular digital multimeter jeneralman ki fè pati handheld multimeter {0{0}}/2 digit ekspozisyon%pandan y ap 4 1/2 ak 5 1" digit (anba a 6 chif) digital multimeter divize nan handheld ak Desktop types. Pi 7b{7}}/2 chif yo oswa pi wo a beg desktop digital multimeters.
The digital multimeter adopts avanse digital ekspozisyon teknoloji ak clear ak entwisyon ekspozisyon ak egzat lekti. Li asire objektivite objektivite nan lekti". 2c men konfòme moun's lekti abitid ak ka kout lekti lekti time. Advantages posede posede tradisyonèl analog (i.e. pointer) multimeters.
ccuracy
presizyon nan yon digital multimeter konbinezon an sistematik ak o aza erè mezi rezilta yo. Li reprezante degre degre konsistans ant mezire valè t Rue valè, ak reflects magnitude mezi mezi err. Jeneralman pale, accuracy, mezi a mezi a erè 2c ak vis versa
presizyon nan yon digital multimeter se pi bon ki nan analog analog multimeter. a multimeter yon trè enpòtan endikatè, ki reflete bon jan kalite ak pwosesis capability multimeter. A multimeter pòv pòv presizyon express vre valè, ki fasil fasil misjijman misjugment mezi.
Resolution
Vòltaj valè korespondan dènye low a vòltaj ranje yon digital multimeter rele rezolisyon, ki reflete sansiblite enstriman mizik la rezolisyon nan digital enstriman ogmante ak nimewo a parèt digits. The pi wo rezolisyon endikatè ke yon dijital multimeter ak diferan diferan chif ka reyalize yo diferan.
The rezolisyon endèks nan yon dijital multimeter parèt lè l sèvi avèk rezolisyon rezolisyon minimum (eskli zewo) enstriman enstriman maximum nimewo a .
It ta dwe pwente rezolisyon rezolisyon ak presizyon de diferan konsèp. ansyen karakterize 22sensitivity" enstriman nan 2c ki se, 2c ability 22reco" ti vòltaj; The latter reflete "accuracy" of mezi a 2c ki se, degre konsistans ant mezi a rezilta ak vrè valè a . De yo nesesèman ki gen rapò ak, so yo pa ka konfonn, kite pou kont li assime rezolisyon rezolisyon (oswa rezolisyon) se menm jan ak acCuracy, ki depann sou complète erè ak quantization erè internal A/D konvètisè ak fonksyonèl konvètisè nan enstriman an . Soti nan mezi mezi pèspektiv 2c rezolisyon 22virtual" indicator (endepandan mezi erè) , pandan y ap presizyon "real" indicator (ki detèmine mezi erè Se poutèt sa, ogmante nimewo ekspozisyon chif abitrèman amelyore rezolisyon enstriman feasible.
measuring range
Nan a multimeteral multimeter multimeter, diferan fonksyon gen korespondan maximum ak minimòm valè ke ka dwe mezire.
Measurement pousantaj
Nimewo fwa a digital multimeter mezi kantite lajan elektrisite ke yo te mezire dezyèm se rele mezi pousantaj 2c ak inite li yo 22times/s. Li sitou depann sou 22times. Li sitou 22times&s. Li Li Sitou pousantaj inite li yo 22times/s. Li sitou depann sou unit li yo 22times/s. Li sitou konvèsyon pousantaj A%A/D konvètè. Gen handheld digital multimeters mezi sik endike vitès time tan konplete mezi pwosesis yo rele mezi mezi sik.
There se yon kontradiksyon ant mezi pousantaj ak presizyon endikatè anjeneral accuracy, mezi a mezi pousantaj 2c ak li balans balans de de. Pou rezoud sa a kontradiksyon nan 2c diferan ekspozisyon chif mezi vitès konvèsyon switch set set menm multimeter: a a fast vit Kovèti pou 2c itilize itilize A/D konvètisè ak fas mezi vitès vitès; By diminye nimewo nan ekspozisyon chif siyifikativman ogmante mezi pousantaj metòd metòd relativman common nan aplikasyon ak satisfè itilizatè mezi pousantaj pousantaj.
Input impedance
Lè mezire vòltaj, enstriman ta dwe gen yon opinyon opinyon impedance, aktyèl mezire sikwi pandan mezi pwosesis minimal ak pa afekte mezire sikwi oswa siyal sous, ki diminye mezi erè.
When mezire aktyèl la enstriman ta dwe gen trè low opinyon impedance, ki minimize enpak enstriman mezire sikwi yo te konekte mezire circuit. Severe, lè l sèvi avèk aktyèl la ranje yon multimeter, ti opinyon impedance, li pi fasil burn enstriman mizik la lè l sèvi avèk li.
