Servicing The Detector; Rinsing The Sample Path - Metrohm 883 Basic IC plus Manual

4.12 Servicing the detector

4.12 Servicing the detector
4.13

Rinsing the sample path

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Follow the maintenance instructions in the the detector's manual.
Before a new sample is measured, the sample path must be rinsed with it
long enough to prevent the measuring result from being falsified by the
previous sample (sample carry-over).
The time required to rinse the sample path with the new sample is called
the rinsing time. The rinsing time depends on the transfer time.
The transfer time corresponds to the time the sample needs to flow from
the sample vessel to the end of the sample loop. The transfer time
depends on the following factors:
The pump capacity of the peristaltic pump or of the Dosino that is used
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for the sample transfer.
The total capillary volume
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The volume of the gas removed from the sample by the sample degas-
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ser (if a sample degasser is present and connected)
The transfer time can be determined as follows:
Determining the transfer time
1 Emptying the sample path
Pump air through the sample path (pump tubing, tubing connec-
tions, capillary in the degasser, sample loop) for several minutes until
all liquid is displaced by the air.
2 Unscrewing the sample loop
Unscrew the end of the sample loop.
3 Aspirating the sample and measuring the time
Aspirate a sample typical for the later application and use a stop-
watch to measure the time the sample needs to go from the sample
vessel to the end of the sample loop.
The time upon stopping the watch is the "transfer time".
4 Tightening the sample loop again
Tighten the sample loop again.
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883 Basic IC plus