But on this occasion we need the help of all you professionals working out in the field. Please read on…
A question that has been keeping me awake at night: Is your manual dip correct?
This has come about In the light of higher accuracy water level sensors we have recently launched from Instrumentation North West (INW) – AquiStar® Smart Sensors. These vented sensors have a “typical” accuracy of 3mm making them one of the most accurate transducer now available for environmental research. They are particularly appropriate for measuring surface water fluctuations.
However, before deployment they require a manual dip to water to establish a reference point from which to analyse the data. Currently this is done with a water level dip meter but this is prone to a number of problems:
Contrary to absolute loggers (like Diver Level Loggers), INW sensors require a manual dip at the start of the deployment but using a poor manual dip will substantially increase the measurement inaccuracy.
So how do we get this datum? In my opinion it may be best to enter a “0” manual dip and insert the datum at a later point but of course we’d still be left with the value of the datum, but this could be obtained anytime in the deployment time sequence.
The question remains: How do we get the (accurate) datum? Can we work without it? (This may be the best route). I’d really like to hear your thoughts on this conundrum – post a reply below or email me on firstname.lastname@example.org.
Vincent van Walt