Originally Posted by Delapool
That's the trouble - it doesn't say. Will post instructions tonight in case I'm stuffing up but will email them as immensely confused now. Ruddy frustrating .
Well in order to verify the accuracy of the drop checker you would have to read the chart at the same dkh
The other thing is, the drop checker is using a substance "something blue" can't remember to check ph. It knows that the only influence on ph is carbonic acid and it knows the dkh
value (again calibrated at source). Using these 3 it can estimate the ppm
So you have discrepancies with 2 different measuring methods of ph 1. Your machine 2. The blue substance in the drop checker.
Then you have the accuracy of the premixed solution calibrated at source.
The chart is also a real time value whereas the drop checker is not real time. This creates another host if potential inaccuracies. This bodes the same when measuring c02 of patient expired gas. There are two types of measuring 1. Main stream 2. Side stream. Mainstream is real time because the sensor is located inline with the intubation tube whereas side stream pulls a sample from the main line to a sensor located elsewhere so the information fed back is a) behind and b) is open to all kinds of other factors which may affect readings such as pressure, temperature etc.
Also the drop checker colour indicator has a 10ppm variation between each colour so there is huge room for inaccuracies there too.
When I say inaccuracies I don't mean that the drop checker is a null method, what I mean is, it can't be easily compared to a real time calculation.
At the end of the day without spending probably thousands of pounds we are limited to low end methods of co2
measurements and the drop checker is accurate to whatever the manufacturers specifications are and the user as far as they are concerned should only be interested in the colour. To me your checker is telling you you have high co2
at a dkh
of 4 based on the measured ph, another checker could tell you something a little different.
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