---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 08/07/11: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:58 PM - Pressure transducer for airspeed (Paul McAllister) 2. 05:12 PM - Re: Pressure transducer for airspeed (Richard E. Tasker) 3. 05:34 PM - Re: Pressure transducer for airspeed (Ken) ________________________________ Message 1 _____________________________________ Time: 03:58:56 PM PST US From: Paul McAllister Subject: AeroElectric-List: Pressure transducer for airspeed Hi All,=0A=0ACould some offer a recommendation for a suitable pressure tran sducer to measure airspeed.- The intended use is to read is with an ADC / Pic Micro along with a few other parameters so I can automate my cowl open ing / closing, and perhaps a few other functions such as gear up warning. =0A=0AThanks,- Paul=0A ________________________________ Message 2 _____________________________________ Time: 05:12:35 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: Pressure transducer for airspeed Silicon Microstructures Inc. makes a nice sensor that can be used for this. The SM5882 is available in 0.6 and 1.5 psi full scale versions (depending on what the maximum speed you want to measure). These are fully conditioned sensors with both analog and digital output. You would use the differential version which you can use directly with the pitot and static inputs to get IAS. Well, not IAS from the pressure sensor. You get the difference between pitot and static pressures that can be converted into IAS with the following equations: Airspeed = ((5.0 * (((((PitotPressure - StaticPressure) / 1013.25) + 1) ^ (2.0 / 7.0)) - 1.0)) ^ 0.5) * 661.48 (where the pressure units are millibar) or Airspeed = ((5.0 * (((((PitotPressure - StaticPressure) / 14.69) + 1) ^ (2.0 / 7.0)) - 1.0)) ^ 0.5) * 661.48 (where the pressure units are psi) If you want to save a bit of money and do all the A/D yourself they also make the SM5652, although the calibration accuracy is not quite as good as the above sensors. To get TAS you would have to have some way of measuring outside pressure (static pressure) separately. They do make a version (SM5822) that will do that. Dick Tasker Paul McAllister wrote: > Hi All, > > Could some offer a recommendation for a suitable pressure transducer to measure airspeed. The intended use is to read is with an ADC / Pic Micro along with a few other parameters so I can automate > my cowl opening / closing, and perhaps a few other functions such as gear up warning. > > Thanks, Paul > * > > > * -- Please Note: No trees were destroyed in the sending of this message. We do concede, however, that a significant number of electrons may have been temporarily inconvenienced. -- ________________________________ Message 3 _____________________________________ Time: 05:34:15 PM PST US From: Ken Subject: Re: AeroElectric-List: Pressure transducer for airspeed Might also be worth looking at the line of sensors similar to the MPX5050DP-ND that I used for an instrument vacuum sensor. They have ones suitable for airspeed if a 0 to 5 volt output is adequate or the microprocessor already has an ADC in it. Sparkfun.com is also a good resource for such projects. Ken On 8/7/2011 8:08 PM, Richard E. Tasker wrote: > > > Silicon Microstructures Inc. makes a nice sensor that can be used for > this. The SM5882 is available in 0.6 and 1.5 psi full scale versions > (depending on what the maximum speed you want to measure). These are > fully conditioned sensors with both analog and digital output. You would > use the differential version which you can use directly with the pitot > and static inputs to get IAS. > > Well, not IAS from the pressure sensor. You get the difference between > pitot and static pressures that can be converted into IAS with the > following equations: > Airspeed = ((5.0 * (((((PitotPressure - StaticPressure) / 1013.25) + 1) > ^ (2.0 / 7.0)) - 1.0)) ^ 0.5) * 661.48 (where the pressure units are > millibar) > or > Airspeed = ((5.0 * (((((PitotPressure - StaticPressure) / 14.69) + 1) ^ > (2.0 / 7.0)) - 1.0)) ^ 0.5) * 661.48 (where the pressure units are psi) > > If you want to save a bit of money and do all the A/D yourself they also > make the SM5652, although the calibration accuracy is not quite as good > as the above sensors. > > To get TAS you would have to have some way of measuring outside pressure > (static pressure) separately. They do make a version (SM5822) that will > do that. > > Dick Tasker > > Paul McAllister wrote: >> Hi All, >> >> Could some offer a recommendation for a suitable pressure transducer >> to measure airspeed. The intended use is to read is with an ADC / Pic >> Micro along with a few other parameters so I can automate my cowl >> opening / closing, and perhaps a few other functions such as gear up >> warning. >> >> Thanks, Paul >> * >> >> >> * > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.