Gamry Instruments EIS Box, Руководство оператора, Страница: 46 / 52

Appendix A: EIS Box Specifications
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14. The voltage across the current measurement resistor, R
m
, is as shown. On ranges below 5 mA, the working
electrode voltage is similar to the voltage across R
m
. At 5 A and 1 MHz, the working electrode voltage can
be as high as 0.51 V, because the cable has both resistive and inductive impedance.
15. The total error in a current measurement is:
Error = Input Current Range Zero Offset × FS C Gain Tolerance × Measured Current
The first term can generally be ignored on the EIS Box. The units for the error are amperes.
16. Drift can be approximated by simple drift in the Range Zero Error. In reality all three terms in the equation
above can have drift.
17. The Current to Voltage converter bandwidth is a function of the current range, the cell cable, and the
IEStability setting. Longer cell cables add capacitance and slow the current measurement.
The specified I/E Converter BW is measured at 5 mA I/E Range.
18. The total error in a voltage setting is:
Error = DC Zero Offset + Gain × Voltage Setting
For a 1 V signal the theoretical error can be as high as 2.5 mV. In practice the error is generally less than 1
mV.
19. This specification is guaranteed by design. It is not tested.
20. This specification is measured by applying zero voltage across a 1 Ω resistor and measuring current noise
on the 500 µA scale. 1 µV of voltage noise creates a current of 1 µA. The filters in the ADC Chain for the I
Signal are used to limit the bandwidths as shown in the specifications. Signal averaging via Gamry DSP
mode further reduces the measured noise.
21. Excluding external power adapter and any cables supplied with unit.
22. Isolation quality has both DC and AC factors, predominantly at the power-supply frequency of 300 kHz.
Only the DC leakage current is shown here. Measured under the following conditions: cell is a 10 k
Ω
resistor, PSTAT mode, CA speed is normal, I/E stability is slow, I/E range is 50 µA, I-channel filter is 5 Hz,
and I-channel gain is 100.