Mafi yawan mafita a cikin kwalbar wasu kayan aiki suna da shawarar da ba su gani ba game da hanyoyi na zahiri na rizistor. Daga baka, daga biyu, wace mai hanyoyi kamar 4.7 kΩ ko 5.1 kΩ amma babu 5 kΩ?
Dalilin ya shafi tashin tsari na rizistor ta hanyoyi, wanda International Electrotechnical Commission (IEC) ta kafa. Wannan tsari ya bayyana sanyoyi masu ma'adani, ciki har da E3, E6, E12, E24, E48, E96, da E192.
Misali:
Sanyar E6 tana amfani da yawan nisa na 10^(1/6) ≈ 1.5
Sanyar E12 tana amfani da yawan nisa na 10^(1/12) ≈ 1.21
A cikin al'umma, ba za a iya kowar rizistoro da duk damar daidai—wannan take da sauki mai haske. Misali, rizistor 100 Ω da 1% sauki ya danganta idan yawan haɗin wannan ya kasance waɗanda 99 Ω zuwa 101 Ω. Don in taimakawa a yi ƙungiyar, American Electronics Industry Association ta kafa tsari masu ma'adani na hanyoyi.
Idan ka duba rizistor 10% sauki: idan akwai rizistor 100 Ω (da sauki na 90 Ω zuwa 110 Ω), ba za a buƙaci rizistor 105 Ω ba, saboda yake za su kasance a ɗaya daga cikin ɗaukan hanyoyi. Anza hanyoyin da za a buƙata ita ce 120 Ω, wanda saukinsa (108 Ω zuwa 132 Ω) tana faru a matsayin ɗaya ɗaya. Saboda haka, a cikin ɗaukan 100 &Ω zuwa 1000 &Ω, ana buƙaci hanyoyin kamar 100 &Ω, 120 &Ω, 150 &Ω, 180 &Ω, 220 &Ω, 270 &Ω, da 330 &Ω. Wannan tana ƙara tsari ɗaban-daban, tare da ƙara abincin ƙungiya.
Prinsipin tashin tsari na eksponensial tana faru a wurareen. Misali, hanyoyin naira na China sun hada 1, 2, 5, da 10 yuan, amma babu 3 ko 4 yuan—saboda 1, 2, da 5 suna iya haɗa don kunshi hanyoyin ɗuka, tare da ƙara tsari ɗaban-daban. Yanaɗu, hanyoyin ƙaramin kalamun suna faru a sanyar 0.25, 0.35, 0.5, da 0.7 mm.
Duk da haka, tashin tsari na logaritmi na hanyoyin rizistor tana taimaka wajen samun hanyoyin da za su fi kan da ɗaukan sauki. Idan hanyoyin rizistor suka faru a sanyar eksponensial na sauki, amfani da hanyoyin kalmomin (gida, rage, darbo, ruɓi) tana faru a ɗaukan sauki da aka sanin.