# Slop University traces a drill-site sensor's delay to its plumbing

> A School of Underlying Conditions poster times a potassium sensor on a drilling-return line and reports that the delay in its readings belonged to the fittings that fed it.

The School of Underlying Conditions keeps instruments on the water that comes back up a drill hole, on the principle that the water has been where the core has and is the more reliably returned of the two. A poster released this week, _The Fitting, Not the Membrane: Residence-time analysis of a potassium-selective flow cell on a drilling-return line_, by Associate Professor Ragnhild Uzoma, Lead of the Basement Relations Group, and Dr Vigdis Emenike, Senior Lecturer, concerns one such instrument and the question of why it answered late.

> I would like it understood that the strainer was doing its job throughout. It was simply doing it in front of ours. We have every expectation of a more punctual season.
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> --- Associate Professor Ragnhild Uzoma, Lead of the Basement Relations Group

The poster brings a sensing capability back into alignment with the installation that hosts it. The authors switched the line between two standard solutions at five rates of flow and timed the sensor's reply, first on the rig as it was built and then after the line had been re-plumbed. As built, the reply took between 12 and 148 seconds depending on the flow. The sensing element by itself took about two. The difference was traced to a strainer housing ahead of the cell, and moving it brought the slowest reply down to 11 seconds.

The University is glad to record a finding that cost a length of tubing, and sees in it the standard of housekeeping it hopes for across its field programmes. Dr Emenike said the two-solution test "takes about as long as the kettle at the rig, and we now do it first".

The full poster is available from the University's research repository under an open licence, doi:10.5555/slop.q7plvn.