Just installed an electric oil pressure gage Circuit Brand (black faced) OEG-12V paired with a Torica OU-101 12V oil pressure sending unit.

Gage reading sweep from 0-10 kg/square meter:
0-2 start
2-6 normal range
6-8 check
8-10 over pressure range

Oil pressure sensor have one terminal only (not the floating type)

I wired the gage terminals given the following using 18 AWG wire:
S - wired to oil pressure sender terminal
G - wired to a body ground within the dashboard
I - wired to a 12V source on the ignition switch when switch is ON.

Now, the problem is:
Gage reading initially was 6 kg/sqcm. Revved the engine and the needle would go down to 3 or 2 kg/sqcm. Upon release of the pedal (decreasing rpm), pressure reading would rise near the max reading of 10 then goes back to 6 kg/sqcm.

after some warmup, gage reading was at 8 kg/sqcm. Revved the engine and the needle would go down to 6 or 4 kg/sqcm. Upon release of the pedal, needle would shoot past the max gage reading of 10 kg/sqcm then go back to 8 kg/sqcm.

as per my knowledge and experience with mechanical oil pressure gages, oil pressure would rise when engine is revved. idle oil pressure is 0.7 kg/sqcm (10 psi). but my electric gage behaves the other way around.

did i miss something? please help. maybe sensor is not compatible with the gage but it's still a guess.

any input or comments is highly appreciated.