LF 1100+
Instruction manual for the
SCHOTT
®
Instruments
Conductivity measuring cells type
LF 513T, 613T, 713T, 713T-250,
LF 813T, 913T, 913T-ID,
LF 1100+, 1100T+, 4100+, 5100+, 5100T+
®
®
Picture of exemplary electrodes
®
SI Analytics GmbH
Hattenbergstrasse 10
55122 Mainz
Germany
Telefon +49 (0) 6131/66 5119
Telefax +49 (0) 6131/66 5001
e-mail: support@si-analytics.com
www.si-analytics.com
Putting into operation
The LF913 T-ID conductivity measuring cell is equipped with an
automatic sensor detection system in the connection plug. This system
stores the sensor type and the serial number as well as the calibration
data. To be able to use the automatic sensor detection feature, you will
need a measurement device supporting this function. For further
information, please refer to the operating instructions of the
measurement device.
2 pole measuring cells (LF1100+,1100T+, 4100+, 5100+, 5100T+,
513T) are delivered platinated.
4 channel and 5 channel conductivity measuring cells (LF613T, 713T
713T-250 and LF 813T, 913T, 913T-ID) are immediately ready for use
and do not need to be platinumplated.
Please check the cell constant prior to the first use. The interval of the
next following verification will depend on the circumstances of use.
The conductivity measuring cell (except LF4100+) has to immerse by
a minimum of 65 mm (ring mark) in the solution to be measured. The
measurement value may be read off as soon as the signal has
stabilised. In the case of temperature changes, this may take up to two
minutes.
The detachable threaded protection cap (only PPO shaft) at the front
end of the measurement cell (LF513T, 613T, 813T) will protect the
glass tube with the platinum rings and determines the cell constant.
Storage and maintenance
The storage conditions for conductivity measuring cells may be within
the range of a 0-50°C and 5-95% relative humidity. Any conditions
leading to condensation of water at the plug ought to be avoided. Prior
to any extended period of storage, the electrodes (platinum rings) of
the measuring cell should be cleaned, if applicable (please refer
below), and the measuring cell should be stored in its original
cardboard box.
Cleaning
Thorough cleaning is particularly recommended prior to measuring low
conductivities. To clean the device, please detach the sensor.
Unscrew and remove the protective cap (only LF513T, 613T, 813T) of
the mesuring cell.
2 pole measuring cells should only be rinsed with water, if necessary
with diluted hydrochloric acid or sodium hydroxide. After mechanical
treatment a platination is necessary, therefore the electrode can be
sent to SI Analytics.
Contamination on the sensor can be removed with the following
procedure:
Grease or oil, carefully clean the glass part and the ring electrodes
using warm water containing a dishwashing detergent and a sponge.
In the case of serious contamination, you may also gently remove it
with an abrasive powder. In the presence of lime, please place the
parts shortly (five minutes) in acetic acid (10Vol%). To clean the
protective cap, please use a small bottle brush or a cotton bud.
When using acids, leaches and solvents for cleaning, please make
sure that they are compatible with the material of the shaft!
An optimum cleaning of the inner glass part of the LF 713 T, LF 713T250 and LF 913 T-ID conductivity measuring cells is achieved with a
tobacco pipe cleaner. The use of acids (exception: HF!), leaches and
solvents is uncritical for these cells.
Exemplified check and setting of the cell constant
To verify the cell constant, you need test solutions, for instance the
SI Analytics ampoules set LF 995. Immerse the measuring cell,
except the LF 4100+, in a suitable test solution by a minimum of 65
mm, for instance in KCl 0.01 mol/l. Then keep the temperature
constant and set the corresponding conductivity value on the
conductometer, for instance 1.413 mS/cm at 25°C for KCl 0.01 mol/l.
For other solutions or different temperatures, please take the
appropriate values from the table. To minimise the measuring
incertainty over the entire range of use, calibration should be
performed both at low and high conductivities. The appropriate cell
constant should be set as a function of the measurement range.
Setting and reading off of the cell constant is done according to the
operating instructions of the conductometer used.
Electrical conductivity mS/cm of KCl solutions as a function of
temperature
KCl concentration mol/l
Temp.(°C) 0,001 0,01 0,1 1
18 0,127 1,225 11,19 98,24
19 0,13 1,251 11,43 100,16
20 0,133 1,278 11,67 102,09
21 0,136 1,305 11,91 104,02
22 0,138 1,332 12,15 105,94
23 0,141 1,359 12,39 107,89
24 0,144 1,386 12,64 109,84
25 0,147 1,413 12,88 111,8
Quality
Each electrode must meet the strict quality requirements of final
testing. The working life depends mainly on the usage conditions.
Hydrofluoric acid, sodium hydroxide and hot phosphoric acid attac
glass.
Further information
Further informations can be found in the laboratory cataloque of
SI Analytics GmbH.
Subject to technical amendment.
GA_LF513-613-813-913_us_T814838_090504
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