Check for Moisture?

[n4gix 4,947]

Does anyone know how I can check for moisture saturation levels? I need to know this for an "ice detection" system.

[phjvh 0]

Good Eastern Frather!Still very cold up here.This is Karl's formula for ice:(A: Total Weight,pounds)(A: Empty Weight, pounds) -(A: Fuel Total Quantity Weight,pounds) -(A: Payload Station Weight: 1,pounds) -(A: Payload Station Weight: 2,pounds) -(A: Payload Station Weight: 3,pounds) -(A: Payload Station Weight: 4,pounds) -(A: Payload Station Weight: 5,pounds) -(A: Payload Station Weight: 6,pounds) -(A: Payload Station Weight: 7,pounds) -(A: Payload Station Weight: 8,pounds) -(A: Payload Station Weight: 9,pounds) -(A: Payload Station Weight:10,pounds) -(A: Payload Station Weight:11,pounds) -(A: Payload Station Weight:12,pounds) -(A: Payload Station Weight:13,pounds) -(A: Payload Station Weight:14,pounds) -(A: Payload Station Weight:15,pounds) -(A: Payload Station Weight:16,pounds) -(A: Payload Station Weight:17,pounds) -(A: Payload Station Weight:18,pounds) -(A: Payload Station Weight:19,pounds) -(A: Payload Station Weight:20,pounds) -(>L:Ice Weight,pounds)%((L:Ice Weight,pounds))%!d! let you read the amounts of ice.((L:Ice Weight,pounds) can "steer" several anti-ice measurements automatically.(A: AMBIENT PRECIP STATE,ENUM) could be useful too.If there is snow, rain or ice, it can influence several functions.At least so it does in my panel.Also not able yet to read dew-point temperature. Jan"Beatus Ille Procul Negotiis"

[n4gix 4,947]

Thanks, Jan. I believe that (A:AMBIENT PRECIP STATE, ENUM) might be the variable I need. I find it odd though, that there is no explanation provided in the SDK to indicate what the possible returns might actually mean. :(One can probably safely assume that a enum value of 0 would mean DRY conditions, but what about the rest?

[hervesors 1]

BillI think calculating ice weight from actual gross weight, empty, fuel and payload weights is another question..as mentioned in another thread here (If I remember), FS carburator icing should depend (not only) on moisture saturation (relative humidity). To the best of my knowledge, there is several formulas for calculating it from static actual outside air temperature (SAT) and dew point temperature (please email me if you need those)..FSUIPC correctly reports DP for the surface temperature layer and approximates it for upper layers.Herv

[phjvh 0]

Fr.4=Rain8=SnowStill looking for the rest.Jan"Procul Negotiis"

[n4gix 4,947]

Thanks, Jan!I'll whip up a quick gauge to simply display the enum value under different conditions to see what the results are.

[Guest Fabio Miguez]

Hey all,Relative humidity depends only on air temperature and dew point, and can be very easily found using this formula http://www.srh.noaa.gov/bmx/tables/rh.htmlIf you have to calculate dew point, and know the RH, use this http://www.paroscientific.com/dewpoint.htm

[phjvh 0]

Fr.Since we can only choose between dry, rain and snow(????),dry=2Further testing in clouds with several temps and dewpoints.Jan"Procul Negotiis"

[n4gix 4,947]

Thanks for the links to the formulas. They will be helpful...But first, I need to retrieve the variable from FSUIPC to make those forumulas useful.That was actually what I was asking for... :)

[Guest Fabio Miguez]

Hey Bill,Just use this method http://forums.avsim.net/dcboard.php?az=sho...10935&mode=full to read FS' memory straight, bypassing FSUIPC. You can use the offset from FSUIPC, and it will probably still be the same, or you can run FS9 under the Visual C debugger, open the computer memory window, break, change the dew point in FS, run, then break again. VC highlights changes in memory in between brakes with red, so you can see what was changed in FS' memory, thereby finding the offset yourself.

[n4gix 4,947]

Thanks, Fabio. I'll take some time to digest Jean-Luc's method and give it a whirl.Since I don't have Visual C, the rest is not relevant to me... but still nice to know! :)

[Guest Karl R Pettersen]

Well, if anyone is able to get the current dew point reading (at aircrafts location and altitude) I would be interrested. Can't believe this parameter value is missing :(As for carburettor ice, I've tried many things, and have come to the conclusion that dew spread means nothing - it is just another means of "engine ice", which ices up with the same settings as structural icing :( Meaning you need freezing temperatures inside an icing cloud to get "engine ice" which carb ice set to hot will fix.Please correct me if I'm wrong.Lowest cloudlayer seem to determine all icing behaviour also as far as I have figured out.