[mrtg] Graphs with offset or predefined range

[mrtg at noegginet.ch]

Dear mrtg list

I am monitoring some temperatur sensors in our serverroom.
That works perfect and I get the graphs I expect.
But different as monitoring the temperature outside a building the temperature inside an air-conditioned room has only a small
hysteresis and most of the graph range is "unused".

Example: the room temperature is between 19 °C and 21 °C. The graph is beginning on the bottom with 0 and scales up to 28 °C. So the
drawed line is quite flat.

Is there any way to set an "offset" for the graph that the range is e.g. between 15 and 30? (so the Graph starts at 15 °C not at 0
°C)

Thanks for any help
Bruce