Hi
Ian
Yep I am familar with 4/20ma current sensors, being a retired electronic engineer and having designed interface equipment for them in the past.
Your belief, based on rotax docs is the following
The sensor reads 4ma for pressures between 0 and 0.75bar, then increases linearly from 0.75bar at 4ma to 20ma at 10.75bar
Is this correct?
If so, dynon asserts that because rotax documentation says the keller sensor is identical to the honeywell sensor, and the honeywell sensor is 0 to 10bar, then the rotax docs are inconsistant, and they have interfaced the keller sensor based on 0 to 10bar.
I have been dealing with dynon and checked their sensor charactorization, and it is indeed 0 to 10bar.
The consequence of this if the sensor is indeed 0.75 to 10.75bar is that the dynon will underread with the error getting worse as you read lower pressures. This will have been the case on dynon skyview equipment since the new sensor was introduced.
Therefore, I am keen on seeing whether the pn456180 has indeed got the 0.75bar offset.
I understand you have checked that the pn456180 outputs 4ma between 0 to 0.75bar. Are you aware of anyone who has checked the other end of the scale, ie at 20ma. Is this 10.75 or 10bar?
Unless this is done, you cannot be sure that the linear gradient is correct. Unfortunately I dont have the pressure equipement to check this.
Because I have a dynon skyview and dynon currently believe the sensor is 0 to 10 bar, I am keen on resolving the inconsistant info from rotax on the electrical equivalence of the honeywell sensor to the keller sensor compared to the transfer function grapgh with the incorr ct xaxis and the 0.75bar offset.
Regards
Doug
