On 24 Jun 2018, at 6:23 am, Andrew Martin andrew@martinag.com.au <flyrotary@lancaironline.net> wrote:

Thanks Todd. This is very good info for making the EM2 just that bit more user friendly for me. Is your airspeed cal in mph or knots?
Andrew

On Sun, 24 Jun 2018 at 5:59 am, Todd Bartrim bartrim@gmail.com <flyrotary@lancaironline.net> wrote:
Below is my EM2 calibration data table. I hope it comes through to the list OK, otherwise I'll post a link.
The only Dynon I have is the D10A, which is just flight instruments, so other than sharing a pitot probe there is nothing common. The Dynon has it's own OAT sensor which is connected through the EDC magnetometer (electronic compass)

EM2 Calibration Data
Ch. # Function Scale Factor Zero Offset Sensor Offset Low Limit Hi Limit sensor type location
0 H2O temp 3.152 20 447 100 VDO 323 095 H2O out of engine, before cooler
1 Aux air 2 3.6 0 69 LM34DZ behind right radiator air
2 aux LT 1 1.825 20 490 VDO ? 323 057 Oil Sump, before cooler
3 RT fuel 0.572 511 756 SW F-385C Right Outboard tank
4 oil temp 3.219 20 445 90 VDO 323 095 Oil into engine, after cooler
5 LT fuel 0.784 511 828 SW F-385B Left Outboard tank
6 aux air 3
7 aux LT 2 3.114 20 446 VDO 323 095 H2O into engine, after cooler
8 oil press 9.436 0 55 25 95 VDO 360 086D Oil into engine, after cooler & filter
9 H2O press 32.211 0 88 21 VDO 360 043 Coolant swirl bottle
10 aux air 1 8.105 0 176 LM34DZ behind left radiator air
11 OAT 8.666 0 439 LM34DZ under right wing root
12 fuel press 13.7 0 99 VDO 360 086 fuel rail loop
13 mixture 5.119 0 0
14 air speed 10.008 0 46 45 200
15 altitude 3.598 -50 7542
16 CHT 1 0.454 0 J type TC fuel filter/water seperator
17 CHT 2 0.454 0 J type TC MOCAL oil inlet
18 CHT 3 0.454 0 J type TC MOCAL H2O inlet
19 CHT 4 0.454 0 J type TC various, currently cowl air out
20 EGT 1 1.046 0 950 K type TC Rotor #1 exhaust
21 EGT 2 1.046 0 950 K type TC Rotor #2 exhaust
22 EGT 3 1.046 0 950 K type TC TIT, turbo inlet
23 EGT 4 1.046 0 500 K type TC exhaust pipe 30" downstream of turbo
24 MAP 13.639 30.029 371
25 voltage 6.277 10 0 130 155

The temp sensor that is in the oil sump (aux LT 1,channel 2) has far different cal data as the other VDO temp sensors. I'm not sure where I got it from and it has no markings on it, but it's ohmic range matches the published data for a VDO 323 057 (max 150C), so I'm assuming that is what it is, but take that one with a measure of skepticism. It calibrated fine so I'm using it for now, but my next order from ACS will include a new VDO 323 095, to match the others.

Todd

Todd Bartrim

On Sat, Jun 23, 2018 at 4:42 AM, Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net> wrote:
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
> --
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-- Regards Andrew Martin Martin Ag