Conas cruinneas iliméadair a ríomh?
Accuracy depends on the error value included in the measurement. The accuracy specification is expressed as follows: " percent of reading plus percent of span". In this formula, " percent of reading" is proportional to reading, and " percent of range" is the offset value. These specifications are developed for each measurement range.
Mura gcomhlíonann an cruinneas riachtanais an réitigh tomhais, ansin níl aon éifeacht ag an réiteach ar an cruinneas. Mar sin féin, is féidir leat multimeter a úsáid fós chun monatóireacht a dhéanamh ar athruithe beaga le linn an tomhais.
Sampla: Cuir i gcás gur mhaith leat comhartha 10 Vdc a thomhas le ilmhéadar 34401A le cruinneas 1 bhliain agus raon 10V, mar sin is é an cruinneas: 0 .0035 móide 0.0005=10 x (0.0035/100) móide 10 x (0.0005/100)=móide /- 0.00040
mar sin:
Luach tomhaiste: 10.00000
Is é atá sa chruinneas ná: móide /-0.00040
Taifeach ná: 0.00001
Tá an léamh iarbhír idir 9.9996 agus 10.0004
Áirítear earráidí sa dá dhigit dheireanacha den tomhas.
Some models of multimeters use "ppm" instead of " percent of reading" and " percent of range". The value of ppm can be obtained by multiplying by 1/1,000,000 (= 10-6).
Sampla 1: Más í earráid 1 (V) ná 10ppm, is é an luach earráide iarbhír ná 1 x 10 x (1/1,000,000) = 0.00001 (V)
Sampla 2: Más é 5ppm an earráid 1 0 (V), is é an luach earráide iarbhír ná 10 x 5 x 10-6=50 u (V)
Sainítear sonraíochtaí cruinnis faoi imthosca sonracha, amhail athruithe ar an teocht chomhthimpeallach agus socruithe ionstraimí (amhail AUTO ZERO ON/OFF).
