Contamination and carryover effects are absent as each sample is introduced into its own sample vial and stays there during the determination
The 832 KF Thermoprep has been developed from the conventional tube oven.
However, instead of introducing the sample into the oven by means of a sample boat, the vial technique is used, ie, the sample is weighed directly into the sample vial, sealed and transferred to the oven.
The 832 KF Thermoprep is a very compact instrument.
Heating block, gas pump, flow meter and flow controller are all integrated, as are the drying flasks.
The oven's construction is so flexible that you can use not only the Metrohm standard sample vials but also those used in your production plant.
Sample preparation is straightforward and consists of weighing the sample into the sample vial, which is then sealed using the crimping tool.
The hermetic sealing of the vials by the PTFE-covered septa reliably prevents any interference by moisture uptake from ambient air.
Moreover, contamination and carryover effects are absent as each sample is introduced into its own sample vial and stays there during the determination as only the water to be determined is transferred to the titration cell.
The vial containing the sample to be analysed is positioned above the oven and lowered into the heating block.
At the same time a double hollow needle pierces the vial's septum.
Via the inlet needle the carrier gas stream is passed through the heated sample.
The carrier gas, loaded with the released moisture, passes through the outlet needle into a tube and then directly into the titration cell. Depending on the sample's water content, the subsequent KF water determination can be carried out volumetrically or, in the trace region, coulometrically.
