MEASUREMENT METHODS OF STATIC MAGNETIC PROPERTIES OF MATERIALS

Merilni sistem Magnet‒Physik Remagraph RE‒3 je namenjen merjenju statičnih magnetnih lastnosti mehkomagnetnih in pol‒trdomagnetnih materialov ter risanju njihovih karakteristik na analogni x‒y risalnik. Proučili smo temelje magnetnih meritev ter delovanje merilnega sistema. Zavrgli smo nekatere zastarele rešitve kalibracije in računanja konstant v navodilih, ki so bile namenjene za uporabo z analognim x‒y risalnikom, ki smo ga nadomestili z več‒funkcijsko merilno kartico NI USB‒6212 ter v programskem okolju LabView napisali program Static Hysteresis. S pomočjo merilne kartice in programa smo merilne signale digitalizirali, vključili digitalno obdelavo merilnih rezultatov ter uvedli postopke za korekcijo izmerjenih karakteristik. Uvedli smo postopke za natančnejše določanje karakterističnih točk na magnetilni in histerezni krivulji, ki so bile poprej podvržene nenatančnemu odčitavanju z grafa analognega x‒y risalnika oz. nekatere celo nedoločljive.Measurement system Magnet‒Physik Remagraph RE‒3 is used for static characterisation of soft and semi‒hard magnetic materials by using an analog x‒y recorder. The basics of magnetic measurement was studied and the abilities of measurement system as well. Some obsolete solutions of calibration and constant calculation, which were used in combination with x‒y recorder, were rejected. The x‒y recorder was replaced by multifunction data acquisition device NI USB‒6212 and the program Static Hysteresis in LabView environment has been written. By program the data acquisition, digital signal processing and procedures for measured characteristics corections were accomplished. Some procedures for accurate determination of characteristic parameters of initial and hysteresis curve were introduced. These parameters were previously subject of inaccurate reading on x‒y recorder graph or even impossible to determine