Metrohm 817 Bioscan - Manual (Page 75)

6.1 Technical data
817 Bioscan
67
Signal output
IE convertor
Azero
Offset
ADC CPU DAC REC
INT
Icell
RS232
Cell
I = I + I + I
cell ADC Azero offset
RS232 INT REC
output
signal +/- 21 µA
( with comp.) +/- 10 V +/- 1V
Max. range 5 nA, 50 nA, 5 µA * idem idem
Max. comp. 16 nA, 160 nA, 16 µA idem idem
Max. signal 21 nA, 210 nA, 21 µA idem idem
Resolution 1 pA, 10 pA, 1 nA Unlimited,
purely analogue
(only limited by
acquisition software) 12 bits (0.5 mV)
Auto zero Resets zero point of
full scale window ** Set to 0 V Set to 0 V
Offset Resets full scale
window to % of full
scale range *** Set relatively to
subrange setting Set as % of full scale
output
Filter
(DC only) Y N Y
* In RS232 data acquisition use always the maximum range settings. Minor
range settings do not amplify the signal, however they limit the full scale.
Minor range settings affect (amplify) the REC output only.
** If a 5 µA range setting is used, the full scale window is –5..+5 µA.After auto
zero at a background current of 1 µA and, this full scale window is –4..+6 µA.
*** If a 5 µA range setting is used, the full scale window is –5..+5 µA. Applying –
50% offset, results in a full scale window of –2.5..+7.5 µA.