I would like to request a longer period between samples be allowed.
It appears the least frequent sample rate currently allowed is 1 hour, though I somehow was able to get 3 hours on the log I started some months ago (setup.jpg)
The reason being, I want to chart coolant conductivity at sample rate of once daily (24 hours).
Conductivity appears to fluctuate inversely to temperature change, and the 3 hour sample rate causes large fluctuations (chart.jpg)

Quoted from "sebastian"

no, 3h is only 8 points per day.

Agreed, a dearth of data points. But I want the chart to run over a year or more to see changes in conductance over long periods.

The problem causing the spike is the impact of coolant temperature on conductivity.
At system start, coolant temperature is at ambient, so the initial sample will be inconsistent with subsequent readings.
I will look at making a virtual sensor that ignores system start data samples.

Is the maximum allowed sample rate 1 hour? I cannot get the field to accept a number larger than that.

Quoted

the fluctualtion is large? i see only a span of +/- 3 µS. Scale your y Range manual to a bigger range and your chart is more flat.

Lies, damned lies and statistics.
Yes the current chart Y value (currently max value = twice current value) can be increased to keep change invisible.
With a current operating temperature conductivity at 7.1 µS, a 3 µS value swing is an ≈ 40% variance.