Amersham Pharmacia Biotech AKTA design pH/C-900, Руководство пользователя

Страница: 26 / 40

Monitor pH/C-900
User Manual 18-1120-06 Edition AC 22
B
Reference information
The factor is expressed in percentage increase of conductivity per
°C increase in temperature. If the temperature compensation
factor is unknown, a general approximate value of 2% can be set
for many common salt buffers.
Set the value to 0 for no temperature compensation.
5 Select sub menu
Setup Cond Ref Temp
, press OK. Select the
reference temperature to which the measured conductivity values
will be converted (normally 20 or 25°C), press OK.
B.2.2 Calibrating the conductivity cell
Normally it is not necessary to adjust the cell constant as the flow
cell is pre-calibrated on delivery. Adjustment is only necessary when
replacing the conductivity flow cell with a flow cell whose cell
constant is unknown. It is also recommended that the conductivity
flow cell is recalibrated after cleaning. When adjusting the cell
constant from UNICORN select
System Control:System:Calibrate
and then select
CondCalib
.
Note: The conductivity temperature compensation must not be used
when adjusting the cell constant. Set the
Setup Cond temp comp
to 0
(see section B.2.1). The temperature sensor must be calibrated before
adjusting the cell constant (see section B.2.6).
1 Prepare a calibration solution of 1.00 M NaCl, 58.44 g/l. Let the
solution stand until it is at room temperature. This is important
for exact measurements.
2 Fill the flow cell completely with the calibration solution, by
pumping at least 15 ml through the cell with a syringe.
3 Stop the flow and wait 15 minutes, until the temperature is
constant in the range 20–30°C.
4 Read the conductivity value displayed and compare it with the
theoretical value from the graph (on opposite page), at the
temperature of the calibration solution. If the displayed value and
the theoretical value correspond, no further action is required.
If the values differ, proceed with actions 5–8.
18-1120-06_AC.qxd 1999-04-14 14:16 Sida 22 (1,1)