Metrohm 796 Titroprocessor - Manual (Page 144)

8.2 DET
796 Titroprocessor, Instructions for use 138 138
Buret cylinder max. rate
1 mL 3 mL/min
2 mL 6 mL/min
5 mL 15 mL/min
10 mL 30 mL/min
20 mL 60 mL/min
50 mL 150 mL/min
A value up to 150 mL/min can be entered even for small
buret cylinders. When the method is executed, however,
the dosing rate will automatically be reduced to the largest
possible value. Select '
max' whenever possible, except with
viscous reagent solutions.
Signal drift
Limits for signal drift
with DET_PH/U/IPOL: 0,5…50…999 mV/Min | off
with DET_UPOL: 0,1…50…100 µA/Min | off
After adding a volume step, the next addition of reagent
is not made until the change in the measured value of
the sensor falls below the indicated value for the signal
drift. If this is delayed, dosing is continued irrespective
on expiry of the pre-set equilibration time (see be-
low).This signal drift control can be switched off
('off’). When the drift control is switched off, the pre-
set waiting time (see below) is strictly adhered to. This
can be useful if the titration reaction proceeds slowly or
the sensor takes a long time to respond.
Equilibr.time
Max. pause before next volume step
0,1…9999 s | auto | off
The full waiting time between one volume increment and
the next volume step takes effect when, with the drift
control switched on (see signal drift, above), the signal
drift does not fall below the pre-set value. Otherwise,
dosing is continued after attainment of the signal drift.
The full waiting time also takes effect if the drift control is
switched off.
The equilibration time function can be switched off. In
this mode, the only decisive factor is the signal drift for
the titration procedure.
In the 'auto' mode the Titroprocessor selects an ap-
propriate equilibration time in line with the pre-set signal
drift. It is calculated using the following formula:
Equilibration time in s
drift mV
( )
/ ( / min) ,
=
+
+
150
0 01
5
For the standard 50 mV setting, this gives a 26 second
equilibration time.