Model SR715 Model SR720 LCR Meters

ACCURACYC + R ACCURACYAccuracy of C = ± [A x K i x K v + (K h + K l ) x 100] %A = Basic Capacitance AccuracyFactor from graph on page 4-6.If the unit is in the constant voltage(CV) mode, or under internal orexternal bias, double the basicaccuracy factor.K i = Integration Time Factor (see K iTable below)K v = Voltage Error Factor (see K v tablebelow).K h , K l = Extreme Range Error Term (seeK h , K l table below).Accuracy of R = ± [A c x (1+1/|D|)] %A c = the accuracy of the capacitancemeasurement (above)and D = R2πfCNote that for small values of D it is possible tohave negative resistance values because theresistance accuracy depends on the magnitude ofC, not of R.For D > 0.1, the impedance accuracy must first becalculated. To do this, first calculate theimpedance of the DUT by adding the resistive andcapacitive elements, either in series or in parallel,as is appropriate. Use the impedance accuracygraph and equation on page 4-2 to obtain animpedance accuracy. The accuracy of C and R arecalculated from the impedance accuracy asfollows:Accuracy of C = ± [Z ac x (1 + |D|)] %Accuracy of R = ± [Z ac x (1 + 1/|D|)] %K i TableMeas Rate Frequency Z m K islow, med all 1fast 100 Hz-1 kHz 6.25 Ω