Biotech-Lab User Manual
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www.ibpmedical.com
Temperature
Conductivity 14 mS/cm NaCl
Temperature Coefficient
Conductivity Readout
Without Compensation
25 °C
14,00 mS/cm
2,000 %/K
14,00 mS/cm
31 °C
15,71 mS/cm
2,035 %/K
14,00 mS/cm
37 °C
17,48 mS/cm
2,070 %/K
14,00 mS/cm
The values 2.00 %/K at 25°C and 2.07 %/K at 37°C are defaults for the respective dialysis machine or values entered by the
user. For demonstration purposes the temperature coefficient for 31°C is mentioned, which is calculated by the sensor from
the values for 25°C and 37°C by linear interpolation.
The calculation below shows the drastic effects of an incorrect temperature coefficient.
Example calculation for an incorrect temperature coefficient, using a dialysate with a temperature coefficient of 2.07 %/°C:
Conductivity Temperature
of
Temperature
Meter
Difference
in
of Solution
Solution
Coefficient of Meter
Display
Values
mS/cm
°C
%/K
mS/cm
%
14,00
37,0
2,07
14,00
0,00
14,00
37,0
1,97
14,17
1,21
7.1.2 WHICH TEMPERATURE COEFFICIENT YOU SHOULD USE
First of all please double-check the temperature coefficient with the machine manual. If you have machines from one
manufacturer only in your use the temperature coefficient that the dialysis machine is using for compensation.
If you have different types of dialysis machines in your unit the best solution is to use a temperature coefficient of 2.07 %/°C
for all machines. This avoids confusion with different readings of the conductivity on different machines.
For your water treatment system use the values according the list above. If the manufacturer is not in this list use the Non-
linear Function (nLF) according to ISO7888 – EN27888.
For tap, purified and waste water we recommend to use the Non-linear Function (nLF) according to ISO7888 –EN27888.
7.1.3 SELECTING THE TEMPERATURE COEFFICIENT
Be aware that changing the temperature coefficient will lead to changes in values displayed by the meter.
Therefore only change the temperature coefficient, if you are fully aware of its consequences. If the temperature
coefficient setting is wrong it will lead to false display values.
Biotech-Lab is able to apply dynamic temperature coefficients. It supports a set of 2 coefficients for 25°C and 37°C
respective. If only one temperature coefficient is needed it is necessary to set both, the coefficient for 25°C and for
37° to the same value.
