Mailing List flyrotary@lancaironline.net Message #1740
From: Tracy Crook <lors01@msn.com>
Sender: Marvin Kaye <marv@lancaironline.net>
Subject: Re: [FlyRotary] Re: EM2 sensors?
Date: Tue, 27 May 2003 01:14:21 -0400
To: <flyrotary>
 

I included the quote below because it was good advice and worth repeating.   Here is the rest of the story on sensors as it applies to the EM2.

 

The EM2 will include a basic set of sensors with the instrument.   I'll update the website soon on which ones are included and which are optional.  The RTD Temperature and pressure sensors used with the EM2 are VDO sensors which are as close to a standard as one can get and are widely available at reasonable prices.  They are available in NPT and metric threads so they can be installed directly into most applications without adapters. 

 

There are also 8 other temperature sensor inputs.  4 J type thermocouple, usually used for cylinder head temps (CHT) and 4 K type thermocouple used for EGTs.  Obviously rotary flyers will not need all of these but the EM2 will be available in a Lycoming version as well. 

 

Air data sensors (TAS, Altitude, VSI, & OAT) are included with the EM2.

 

Fuel gauge sensors are Stewart Warner as used in Van's Aircraft (not included)

 

If you already have other type sensors, all is not lost.  An additional feature on the EM2 is a calibration screen.  This is primarily to calibrate the EM2 for greater accuracy than can be done with fixed calibration (sensor do vary a bit) but it can also be used to calibrate for other sensors if they are of the same type (RTD, linear voltage, etc).   I would still recommend using the VDO sensors that the EM2 was designed with.

 

If you are using an EC2 engine controller you do not need a fuel flow sensor since the EM2 gets fuel flow infomation from the engine controller.  Lycoming drivers and carbureted rotaries will have to buy an optional Flo Scan sensor. 

 

The picture of the EM2 on the website is already obsolete due to improvements in display layout.  Some data is now provided in bargraph form in addition to digital.  In some cases, analog more pilot friendly.

 

There is lots more I could go into but if I don't get back to working on programming, the EM2 won't be ready for its June introduction.  Several builders ask "June what?"  Don't know yet but I'll be happy if it is June 30th.

 

Dancing as fast as I can,

 

Tracy
tcrook@rotaryaviation.com
www.rotaryaviation.com

 

Rusty asked:

 " Are these stock temp sensors compatible with most gauges, specifically the EM-2 (Tracy?) ?   If not, how hard is it to find the correct sensors that will screw into these metric holes (in the US)?   Does anyone know what the thread size of these holes is? " 

 

Tommy James answered:

 

Based on tough experience, choose the Gauge first.  It will determine what kind of sensor it is happy with.  Not all sensors will work for any one gauge.  The Grand Rapids EIS uses some sensors that require a resistor wired in to give the proper reading,  also 'exciter' power is needed to some.  Tracy's system will doubtless require specific sensors just like the other makers.  Wait and see what is needed then buy the sensor.

 

JC Whitney sells a little package of metric to NPT adapters that you will need to fit the NPT sensors to the metric block.  These are cheap, so buy 2-3 packs.    As I remember off the top of my head, they are 10mm fine (?) pitch male to 1/8" NPT female.

 

 

 

 

 

 

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