Ma ja sam i pitao za tačnost kod kalibracije jer ne znam. Ali dosta su slični ali ipak različiti pojmovi tolerancija i tačnost. Posebno što oba mogu da koriste % pa može doći do zabune. Valjda ima neko ko se bavio standardima i slično pa je upoznat. To je meni više kao pravo
I vjerovatno se u različitim oblastima i drugačije koriste.
Prvo vezano za preciznost. Preciznost je koliko su grupisana mjerenja.
Recimo ono klasično poređenje sa metom, ali može samo linijski, sa mjerenjem brzine. Imaš grupu pogodaka daleko od centra, sa malim raspršivanjem hitaca, ali nisi pogodio ni jednom centar. Tada je recimo puška/strijelac, precizna ali nije tačna. Ako druga ima manu preciznost, ali je grupa pogodaka oko centra mete. Ona je manje precizna, ali je tačnija. I sada od tolerancije zavisi šta je tačno, a šta ne. Odnosno, koliko je velik dio mete koji uzimaš da je pogodak tačan ili ne.
Ako sam to tačno rastumačio
Što se tiče radara, onih na Doplerovom efektu. Nama je asistent donosio neki domaći, FOX radar, Koji nije prošao domaći tender. Uvoznički lobi
Mislim da su ga u Kosmosu napravili i da je bio projekat još od prije rata. I radar se testirao zvučnom viiljuškom gdje se njegova funkcionalnost potvrđivala ako očita brzinu 22 +/- 2 km/h. Naravno, postoji bolja metoda sa antenom, generatorom i mješačem. Tako se vjerovatno i radi kalibracija. Ali tu treba paziti i na ugao, jer njegov kosinus utiče na mjerenje. Pa treba fiksirati i kod zvučne rešetke da oba njena kraka budu u liniji sa radarom... A kod realnih situacija taj ugao se ne može izbjeći. Još ako je mobilan radar, pa treba znati i njegovu tačnu brzinu...Ali se ne sjećam priče oko tolerancije i tačnosti tada.
Ima ovo.
Citiraj:
Calibration Tolerance: Every calibration should be performed to a specified tolerance. The terms tolerance and accuracy are often used incorrectly. In ISA’s The Automation, Systems, and Instrumentation Dictionary, the definitions for each are as follows:
Accuracy: The ratio of the error to the full scale output or the ratio of the error to the output, expressed in percent span or percent reading, respectively.
Tolerance: Permissible deviation from a specified value; may be expressed in measurement units, percent of span, or percent of reading.
As you can see from the definitions, there are subtle differences between the terms. It is recommended that the tolerance, specified in measurement units, is used for the calibration requirements performed at your facility. By specifying an actual value, mistakes caused by calculating percentages of span or reading are eliminated. Also, tolerances should be specified in the units measured for the calibration.
All test equipment readouts are accurate only to a certain level of uncertainty, or tolerance. The best test equipment has LOW uncertainties, but NO test equipment can give you a 100% correct output or input reading – there is a tolerance for all equipment.
Accuracy: The ratio of the error to the full scale output or the ratio of the error to the output, expressed in percent span or percent reading, respectively.
Tolerance: Permissible deviation from a specified value; may be expressed in measurement units, percent of span, or percent of reading.
As you can see from the definitions, there are subtle differences between the terms. It is recommended that the tolerance, specified in measurement units, is used for the calibration requirements performed at your facility. By specifying an actual value, mistakes caused by calculating percentages of span or reading are eliminated. Also, tolerances should be specified in the units measured for the calibration.
All test equipment readouts are accurate only to a certain level of uncertainty, or tolerance. The best test equipment has LOW uncertainties, but NO test equipment can give you a 100% correct output or input reading – there is a tolerance for all equipment.
https://jmtest.com/out-of-tolerance-ris ... libration/
Pa prema ovome bi tolerancija trebala biti izražena u jedinicama mjere da bi se pravila razlika u odnosu na tačnost koja bi trebala biti u procentima. Odnosno % FS ili % RD. Sada se vraćam na onu verifikovanu tačnost od +/- 3 km/h.
I ovo bolje prebaciti u temu o radarima
