Knauer Azura ECD 2.1, Instructions Manual

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40 Detection and Parameters
AZURA® Detector ECD 2.1 Instructions, V6685
6.5 Parameters
Operational parameters are controlled from the SETUP screens in the
ECD 2.1. Parameters are filter, cell potential and offset. Temperature is set
in CONFIG menu.
Fig. 24 Selection of parameters in the ‘DC SETUP’ screen. Temperature is set
in CONFIG menu.
Range
Range selection is done in the ‘SETUP’ or ‘STAT’ screen in DC, PULSE and
SCAN mode. A number of ranges can be selected; the maximum current
that can be compensated for using auto zero and offset differs. The high
sensitivity ranges (10 pA - 5 nA) have the best noise specifications. In fact,
there is a trade-off between best noise specification at sensitive ranges,
and maximum compensation at the less sensitive ranges. This is an inevi-
table consequence of the tremendous dynamic range that is covered by
electrochemical detection.
Table II. DC ranges and maximum compensation:
Range FS Max comp Range FS Max comp
200 µA 2.5 mA 20 nA 2.5 µA
100 µA 2.5 mA 10 nA 2.5 µA
50 µA 2.5 mA 5 nA 250 nA
20 µA 2.5 mA 2 nA 250 nA
10 µA 2.5 mA 1 nA 250 nA
5 µA 2.5 mA 500 pA 250 nA
2 µA 25 µA 200 pA 250 nA
1 µA 25 µA 100 pA 25 nA
500 nA 25 µA 50 pA 25 nA
200 nA 25 µA 20 pA 25 nA
100 nA 25 µA 10 pA 25 nA
50 nA 2.5 µA
In the PULSE and SCAN mode, current is much higher than in DC mode.
Therefore it is not possible to select pA ranges.
T e m p = 3 0 ° C C o n t r a s t = 2 0 C O N F I G
V a l v e = 3 V o u t s o u r c e = D A C
I D 1 m a s t e r = n o
P R E V I O
R a n g e = 5 0 n A M a x C o m p = 2 . 5 µ A D C 1
E c = + 0 . 5 0 V # O f f s = + 1 0 % S E T U P
F i l t = . 0 0 2 H z
P R E V P O L A R = + E V E N T S N E X T