|
|
Hi there Todd
I’d be very interested in the settings though I have an EM3 and I’m not sure of the difference between models 2 and 3.
Do you have all seperate senders for the Em2 and Dynon?
Steve Izett
> On 23 Jun 2018, at 5:33 pm, Todd Bartrim bartrim@gmail.com <flyrotary@lancaironline.net> wrote:
>
> Ok, as I can never leave well enough alone, I took another look at this.
> First as soon as I took a moment I realized that the J&K thermocouple would be real easy to calibrate and convert to metric.
> I used a Fluke temperature calibrator with a millivolt output to simulate the TC"s. Worked like a charm.
> I tried to use the same calibrator to simulate the variable resistance of the VDO probes, but they are thermistors which are very non-linear, so even with the tables it was a challenge.
> So I brought home a Fluke 9009 dual dry block temperature calibrator. Good for -20°C up to 350°C at the same time (separate temp wells).
> That made it easy, fast and very accurate.
> However, the one that I'm worried about is the OAT as this one is also used to calculate TAS, HP, and "other readings".
> Now I believe I can correct the TAS by calibrating the scale factor on the airspeed in flight against the TAS on my Dynon.
> HP is an arbitrary number anyways based on what I think my max HP should be. I think I can tweak that factor as well to get it back to what I think it should be. And if I ever meet a Dyno I'll be sure to try to calibrate it properly.
> But the manual also mentions "other readings" without details.
> So I've put in an email to Tracy.
> If it turns out to be important, I can always put this one back and just ignore the OAT. (Its also on the Dynon)
> So if any of you metric blokes down under would like to do this, I can post all the parameters which you can input to your own EM2 and it will get you close.
> For very accurate calibration you would have to tweak them a bit using a temperature calibrator.
>
> Todd
>
> On Fri, Jun 8, 2018, 00:46 Todd Bartrim bartrim@gmail.com, <flyrotary@lancaironline.net> wrote:
> Hi Andrew;
> I haven't spent much further time on the metric conversion. I think it wouldn't be as simple as I hoped. It was fairly straight forward to convert the fuel level to litres and most of the temp measurements should be almost as easy, but the K & J thermocouples have different raw data, that I don't believe would be easy to convert. And then some of the calculated parameters will likely be adversely affected as well. Probably not impossible, but first, I just don't have the time and second, I would probably have to be bugging Tracy a lot for info and he's busy being retired in the mountains of Colorado where he seems to be online only occasionally.
> I have however longed for a data-logger which the early EM2 didn't have (I have #003). With the increasing popularity of hobby microcontrollers I can get a Ardurino microcontrollers for $35 and a datalogger for it for $6, so I just asked Tracy about the possibility of harvesting data from the EM2.
> However for a few other reasons, I'm considering that next time someone on the list is selling an EM3 from an abandoned project, I might buy it for an upgrade. I think there was one recently but it was bought up right away.
>
> Todd Bartrim
>
> On Thu, Jun 7, 2018 at 7:58 PM, Andrew Martin andrew@martinag.com.au <flyrotary@lancaironline.net> wrote:
> Todd, did you ever get the EM2 recalibrated to metric? I never attemped this as doing so usually gives me quite a few hours work to get back to a working system. I used Tracy’s factory calibration in the EM2 as the base to calibrate my efis, which is in metric. It is a minor inconvienience to do the mental arithmetric when comparing instruments, but would be interesting to know if you succeeded.
> --
> Regards Andrew Martin Martin Ag
>
|
|