And more specifically, right from our specs:
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RPM:
When oil temp is below 120 deg F, the Tachometer shall have a redline from 0-1400 RPM, yellow from 1400-1800, green from 1800 to 2500, yellow from 2500 to 4000, red from 4000 to 6000.
When oil temp is above 120 deg F, the Tachometer shall have a redline from 0-1400 RPM, yellow from 1400-1800, green from 1800 to 5500, yellow from 5500 to 5800, red from 5800 to 6000.
When at 0 RPM, the low RPM alarm shall be inhibited.
When going from 0 RPM to any RPM, low RPM alarms shall be inhibited for 10 seconds.
High RPM alarms shall always be active.
Oil Temp:
When oil temp is below 120 deg F, the oil temp shall have a yellow line from 100-120 deg F. It shall have a black line outlined in white from 120-190 deg F. Green from 190-230, yellow from 230-266, red from 266-280.
When oil temp is greater than 190 deg F, the oil temp shall have a yellow line from 100-120 deg F. It shall have a green line from 120-230, yellow from 230-266, red from 266-280.
When oil temp is between 120 deg F and 190 deg F, the area from 120-190 deg F shall be:
Green if the temperature has been above 190 more recently than it has been below 120 deg F.
Black with a white outline at other times, including at boot if needed.
Only alarm on oil temp shall be for the high red zone.
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All of the above behaviors basically reflect a few requirements described in the 912 documentation: The oil should to be heated to 190 deg F every flight, after which, any value above 120 is basically "in the green". Also, rpm should have a lower redline until the oil heats up.