These Applications Notes are offered for guidance only. They have been supplied to us by DB1 users. However, we can offer no guarantees of their effectiveness. Biotronics Ltd accepts no liabilities for losses incurred by use of these methodologies.
DB1 Embryofreeze Temperature Stability
Results
Results are recorded from the commencement of the program run since the initial settling temperature is in ‘freefall’ and bears little relevance to a time-based test. In the laboratory the ambient temperature was 22.4 oC (by the external thermocouple) For the actual test both tracking readings (the sample temperature and the thermocouple temperature) adhered to the planned demand curve.
Click for the full chart.
When analysing the errors it can be seen that the UUT performs well within its specification.
For the purpose of analysis the chart below plots the absolute error in oC of sample temperature, thermocouple temperature, and a normalised thermocouple temperature which is the average thermocouple offset subtracted from each thermocouple reading.
There seems to be an anomalous reading at the 78th minute which is probably due to the testing environment.
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Ignoring the anomalous reading, and attributing the thermocouple error to a zero offset problem, it can be seen that the sample temperature tracks the demand temperature within the demands of the specification.
The sample to demand temperature error deviation is –0.5 oC to +0.1 oC and this is within the specified aim temperature resolution of 1 oC in 1 minute.
The normalised thermocouple error deviation is –1.26 oC to +0.54 oC which conforms the specifications sample temperature requirement given the obtainable accuracy of a K-type thermocouple.
