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VOCABULAR international de termeni utilizati in metrologie - UTM

VOCABULAR international de termeni utilizati in metrologie - UTM

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Nota<br />

Conditiile <strong>de</strong> refer<strong>in</strong>ta cupr<strong>in</strong>d <strong>in</strong> general valori <strong>de</strong> refer<strong>in</strong>ta sau <strong>in</strong>tervale <strong>de</strong> refer<strong>in</strong>ta<br />

pentru marimile <strong>de</strong> <strong>in</strong>fluienta care afecteaza mijlocul <strong>de</strong> masurare.<br />

5.8. CONSTANTA (A UNUI MIJLOC DE MASUIRARE) - coeficient cu care trebuie<br />

<strong>in</strong>multita <strong>in</strong>dicatia directa a unui mijloc <strong>de</strong> masurare pentru a obt<strong>in</strong>e valoarea <strong>in</strong>dicata a<br />

masurandului sau valoarea unei marimii care este utilizata <strong>in</strong> calculul valorii masurandului.<br />

Note<br />

1.Mijloacele <strong>de</strong> masurare cu mai multe domenii <strong>de</strong> functionare, prevazute cu un s<strong>in</strong>gur<br />

dispozitiv <strong>de</strong> afisare, au mai multe constante, fiecare corespunzand, <strong>de</strong> exemplu, pozitiilor diferite<br />

ale unui mecanism selector.<br />

masurare.<br />

2.Cand constanta este numarul 1, acesta nu este, <strong>in</strong> general, <strong>in</strong>dicat pe mijlocul <strong>de</strong><br />

5.9. CARACTERISTICA DE TRANSFER - relatie <strong>in</strong>tre un semnal <strong>de</strong> <strong>in</strong>trare si<br />

raspunsul corespunzator <strong>in</strong> conditii <strong>de</strong>f<strong>in</strong>ite.<br />

Exemplu<br />

Tensiunea electromotoare a unui termocuplu <strong>in</strong> functie <strong>de</strong> temperatura.<br />

Note<br />

unui grafic.<br />

1.Relatia poate fi exprimata sub forma unei ecuatii matematice, a unui tabel numeric sau a<br />

2.Cand semnalul variaza <strong>in</strong> functie <strong>de</strong> timp, o forma a caracteristicii <strong>de</strong> transfer estefunctia<br />

<strong>de</strong> transfer ( catul d<strong>in</strong>tre transformata Laplace a semnalului <strong>de</strong> iesire si transformata Laplace a<br />

semnalului <strong>de</strong> <strong>in</strong>trare ).<br />

5.10. SENSIBILITATE – cat <strong>in</strong>tre cresterea raspunsului unui mijloc <strong>de</strong> masurare si<br />

cresterea corespunzatoare a semnalului <strong>de</strong> <strong>in</strong>trare.<br />

Nota<br />

Valoarea sensibilitatii poate <strong>de</strong>p<strong>in</strong><strong>de</strong> <strong>de</strong> valoarea semnalului <strong>de</strong> <strong>in</strong>trare.<br />

5.11.(5.12.) (PRAG DE) DISCRIMINARE, (PRAG DE) MOBILITATE – Cea mai<br />

mare modificare a unui semnal <strong>de</strong> <strong>in</strong>trare care nu produce o modificare <strong>de</strong>tectabuila a<br />

raspunsului unui mijloc <strong>de</strong> masurare, variatia semnalului <strong>de</strong> <strong>in</strong>trare fi<strong>in</strong>d lenta si m<strong>in</strong>otona.<br />

Nota<br />

Pragul <strong>de</strong> sensibilitate poate <strong>de</strong>p<strong>in</strong><strong>de</strong>, <strong>de</strong> exemplu, <strong>de</strong> zgomotul <strong>in</strong>tern sau extern sau <strong>de</strong><br />

frecare. El poate sa <strong>de</strong>p<strong>in</strong>da si <strong>de</strong> valoarea semnalului <strong>de</strong> <strong>in</strong>trare.<br />

5.12.(5.13.) REZOLUTIE (a unui dispozitiv <strong>de</strong> afisare) - cea mai mica diferenta <strong>in</strong>tre<br />

<strong>in</strong>dicatiile unui dispozitiv <strong>de</strong> afisare care poate fi perceputa <strong>in</strong> mod semnificativ.<br />

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