Fluxgate compass location

[Halfhitch]

I am in stalling an autopilot and have found a perfect location for the fluxgate compass. Exactly centerline and 2/5 of boat length forward of the transom. It will mount to the forward side of a crossbeam and I have a snake in there from the area where the computer will be. But, it is near the sending unit for the fuel gauge. I know a strong magnetic field or heavy electrical draw will adversely affect the fluxgate but do you think the small amount of current active in the fuel sensor would be detrimental for recreational performance. I'm sure there are fancy meters that can measure some interference there but in the real world is this going to lead my AP astray? Whaduhyuhthink?

 

[Fishtales]

I have the same one in my boat. I mounted it under the mid berth area in about the same location. I'm guessing it would be ok there.

 

[wspitler]

If you have a handheld mag compass, pass it by the location you plan to mount the fluxgate and see how much deviation you get. The current draw from the sensor should be minimal. The tank sensor has a stainless steel probe which should be OK. Not sure if there is any other ferrous material in the sender which is pretty close. The course computer can correct for a limited amount of deviation, but of course, less is better. A cheap handheld will work. Try passing it in the vicinity of a screwdriver for example and you'll be surprised how much it will deviate.

 

[Halfhitch]

Bill, Thanks for that idea. I went out and did as you said, first with the power off and then with the gauge active. Both times there was no negligible movement of the needle on a decent quality Brunton compass. So, its' on with the project.