PRONOVA FOS/TAC 2000, Руководство пользователя

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FOS/TAC 2000 PERFORMING A FOS/TAC MEASUREMENT
812-04.2015-EN FOS/TAC 2000 User Manual 13
6 Performing a FOS/TAC measurement
6.1 Sample preparation
Variant 1:
Centrifuging the sample
Whenever possible, the original sample should be centrifuged 20 minutes with a relative centrifugal acceleration rate of 15,000xg.
The purpose of this is to eliminate the solid constituents from the sample which feature properties similar to those of the substances
to be analyzed by way of FOS/TAC determination and which would hence distort the result. The sample must now be weighed and
topped up with distilled water as described below.
Variant 2:
Sieving the sample
If no centrifuge is available, it is also possible to use a close-meshed sieve in order to eliminate the solid constituents. In this case, a
spoon should be used in order to strain the original sample through the sieve.
Sieving the fermenter substrate
Weighing and topping up the sample
In order to weigh the sample, place a 50-ml beaker with a stir stick on the scales. Switch on the scales or press the “TARE” key in
order to reset scales to 0.00g.
Now fill 5.0g of the centrifuged or sieved sample into the beaker and top up with 15g of distilled water to 20.0g. Make sure to adhere
precisely to the quantities stated because this dilution ratio is the basis of the calculation of the FOS and TAC values by the device!
Resetting the scales Filling in the sample Weighing in 5.0g of the Topping up with distilled water Finished final sample
sample 20.0g