Vario pneumatics

[Colin Roney]

Does anyone have a solution to the problem of having two `flask` varios
fitted with one total energy tube.
I understand, although I may be wrong, that having a tee piece split near
to the panel to provide the two t/e requirements is a `no no`.

[Martin Gregorie[_5_]]

On Sun, 19 Dec 2010 12:38:41 +0000, Colin Roney wrote:

> Does anyone have a solution to the problem of having two `flask` varios
> fitted with one total energy tube.
> I understand, although I may be wrong, that having a tee piece split
> near to the panel to provide the two t/e requirements is a `no no`.

There's an article on the Borgelt site about it:
http://www.borgeltinstruments.com

Select Articles from the menu bar and then Installation from the side
bar. Scroll down to 'Pneumatic' in the 'Good practise hints' section.
This is about 3/4 of the way down the page.

--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[Dan[_4_]]

On Dec 19, 7:38*am, Colin Roney > wrote:
> Does anyone have a solution to the problem of having two `flask` varios
> fitted with one total energy tube.
> I understand, although I may be wrong, that having a tee piece split near
> to the panel to provide the two t/e requirements is a `no no`.

There is an article on TE compensation at http://www.schempp-hirth.com/index.php?id=108&L=1
that also makes recommendations; a good read.

[Tim Mara]

you will likely get some error in the instruments, most variometers with
capacity flasks are "calibrated leak" or thermister type variometers (heated
wire/air flow). Having more leaks in the system will have some effect on the
actual readings but this leak is rather small for most instruments..actually
pretty amazing that an instrument can read such small airflows and
temperatures to begin with and translate these to instrument indications
when you really think about it! Most sailplane instrument installations do
have small errors (some have large errors!) and the pilots don't even
recognize the errors.....many sailplane variometers are from the start
highly inaccurate..you can't always believe simply because the seller has a
great looking ad and touts all the fine features that the actual instrument
is producing the fine accuracy they might claim...pretty easy today with all
the electronics components for someone to take a collection of easily
available components and toss them in a box and produce something the
appears to be an aircraft instrument! Pilots may tend to see a needle go up
or down and either slow down and circle or speed up and run away...and the
indications are pretty much telling you that you've encountered a higher or
lower pressure and hence all works out....sort of ..
But that said, you can live with some small errors that cannot be completely
corrected.....or use different pneumatic systems to avoid connecting
calibrated leak systems..most newer variometers have adjustments to
compensate for minor errors and electronic TE variometers don't require
connection to TE but may be connected to pitot and static alone and adjusted
for higher accuracy.
If in fact you have one of the older electric variometers with a capacity
flask and a pneumatic variometer like a Winter or PZL then likely your
eclectic variometer is a very old and likely highly inaccurate instrument
now anyway. It's older for sure, no new electric variometers rely on this
technology anymore and so it may be due or overdue to replacement or at
least testing for it's own leaks and errors and even without the errors from
connection with another capacity instrument may never give you totally
accurate indications.
tim
Please visit the Wings & Wheels website at www.wingsandwheels.com


"Colin Roney" > wrote in message
...
> Does anyone have a solution to the problem of having two `flask` varios
> fitted with one total energy tube.
> I understand, although I may be wrong, that having a tee piece split near
> to the panel to provide the two t/e requirements is a `no no`.
>
>
>
>
>
>
>
>
> __________ Information from ESET NOD32 Antivirus, version of virus
> signature database 5715 (20101219) __________
>
> The message was checked by ESET NOD32 Antivirus.
>
> http://www.eset.com
>
>
>



__________ Information from ESET NOD32 Antivirus, version of virus signature database 5716 (20101219) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com

[Andy[_1_]]

On Dec 19, 9:03*am, "Tim Mara" > wrote:
> you will likely get some error in the instruments, most variometers with
> capacity flasks are "calibrated leak" or thermister type variometers (heated
> wire/air flow). Having more leaks in the system will have some effect on the
> actual readings but this leak is rather small for most instruments..actually
> pretty amazing that an instrument can read such small airflows and
> temperatures to begin with and translate these to instrument indications
> when you really think about it! Most sailplane instrument installations do
> have small errors (some have large errors!) and the pilots don't even
> recognize the errors.....many sailplane variometers are from the start
> highly inaccurate..you can't always believe simply because the seller has a
> great looking ad and touts all the fine features that the actual instrument
> is producing the fine accuracy they might claim...pretty easy today with all
> the electronics components for someone to take a collection of easily
> available components and toss them in a box and produce something the
> appears to be an aircraft instrument! Pilots may tend to see a needle go up
> or down and either slow down and circle or speed up and run away...and the
> indications are pretty much telling you that you've encountered a higher or
> lower pressure and hence all works out....sort of ..
> But that said, you can live with some small errors that cannot be completely
> corrected.....or use different pneumatic systems to avoid connecting
> calibrated leak systems..most newer variometers have adjustments to
> compensate for minor errors and electronic TE variometers don't require
> connection to TE but may be connected to pitot and static alone and adjusted
> for higher accuracy.
> If in fact you have one of the older electric variometers with a capacity
> flask and a pneumatic variometer like a Winter or PZL then likely your
> eclectic variometer is a very old and likely highly inaccurate instrument
> now anyway. It's older for sure, no new electric variometers rely on this
> technology anymore and so it may be due or overdue to replacement or at
> least testing for it's own leaks and errors and even without the errors from
> connection with another capacity instrument may never give you totally
> accurate indications.
> tim
> Please visit the Wings & Wheels website atwww.wingsandwheels.com
>
> *"Colin Roney" > wrote in . ..
>
>
>
> > Does anyone have a solution to the problem of having two `flask` varios
> > fitted with one total energy tube.
> > I understand, although I may be wrong, that having a tee piece split near
> > to the panel to provide the two t/e requirements is a `no no`.
>
> > __________ Information from ESET NOD32 Antivirus, version of virus
> > signature database 5715 (20101219) __________
>
> > The message was checked by ESET NOD32 Antivirus.
>
> >http://www.eset.com
>
> __________ Information from ESET NOD32 Antivirus, version of virus signature database 5716 (20101219) __________
>
> The message was checked by ESET NOD32 Antivirus.
>
> http://www.eset.com

Don't give the electronic flow type varios too bad a rap. In my
opinion the Cambridge MNAV vario was very good. Of course the glide
computer became obsolete when GPS arrived on the scene.

Andy

[Wayne Paul]

The PDF version of the Borgelt installation article can be found at
http://www.borgeltinstruments.com/instrumentinstallation.pdf

Wayne
http://www.soaridaho.com/

"Martin Gregorie" > wrote in message ...
> On Sun, 19 Dec 2010 12:38:41 +0000, Colin Roney wrote:
>
>> Does anyone have a solution to the problem of having two `flask` varios
>> fitted with one total energy tube.
>> I understand, although I may be wrong, that having a tee piece split
>> near to the panel to provide the two t/e requirements is a `no no`.
>
> There's an article on the Borgelt site about it:
> http://www.borgeltinstruments.com
>
> Select Articles from the menu bar and then Installation from the side
> bar. Scroll down to 'Pneumatic' in the 'Good practise hints' section.
> This is about 3/4 of the way down the page.
>
> --
> martin@ | Martin Gregorie
> gregorie. | Essex, UK
> org |

[sisu1a]

> I understand, although I may be wrong, that having a tee piece split near
> to the panel to provide the two t/e requirements is a `no no`.

Short answer: Move the tee split under the seatpan to avoid crosstalk.

-p

[Tim Mara]

the M/Nav and even L/Nav and S/Nav were the last of even Cambridges use of
old thermister technology....they also switched to pressure transducers with
all later products
tim

"Andy" > wrote in message
...
On Dec 19, 9:03 am, "Tim Mara" > wrote:
> you will likely get some error in the instruments, most variometers with
> capacity flasks are "calibrated leak" or thermister type variometers
> (heated
> wire/air flow). Having more leaks in the system will have some effect on
> the
> actual readings but this leak is rather small for most
> instruments..actually
> pretty amazing that an instrument can read such small airflows and
> temperatures to begin with and translate these to instrument indications
> when you really think about it! Most sailplane instrument installations do
> have small errors (some have large errors!) and the pilots don't even
> recognize the errors.....many sailplane variometers are from the start
> highly inaccurate..you can't always believe simply because the seller has
> a
> great looking ad and touts all the fine features that the actual
> instrument
> is producing the fine accuracy they might claim...pretty easy today with
> all
> the electronics components for someone to take a collection of easily
> available components and toss them in a box and produce something the
> appears to be an aircraft instrument! Pilots may tend to see a needle go
> up
> or down and either slow down and circle or speed up and run away...and the
> indications are pretty much telling you that you've encountered a higher
> or
> lower pressure and hence all works out....sort of ..
> But that said, you can live with some small errors that cannot be
> completely
> corrected.....or use different pneumatic systems to avoid connecting
> calibrated leak systems..most newer variometers have adjustments to
> compensate for minor errors and electronic TE variometers don't require
> connection to TE but may be connected to pitot and static alone and
> adjusted
> for higher accuracy.
> If in fact you have one of the older electric variometers with a capacity
> flask and a pneumatic variometer like a Winter or PZL then likely your
> eclectic variometer is a very old and likely highly inaccurate instrument
> now anyway. It's older for sure, no new electric variometers rely on this
> technology anymore and so it may be due or overdue to replacement or at
> least testing for it's own leaks and errors and even without the errors
> from
> connection with another capacity instrument may never give you totally
> accurate indications.
> tim
> Please visit the Wings & Wheels website atwww.wingsandwheels.com
>
> "Colin Roney" > wrote in
> . ..
>
>
>
> > Does anyone have a solution to the problem of having two `flask` varios
> > fitted with one total energy tube.
> > I understand, although I may be wrong, that having a tee piece split
> > near
> > to the panel to provide the two t/e requirements is a `no no`.
>
> > __________ Information from ESET NOD32 Antivirus, version of virus
> > signature database 5715 (20101219) __________
>
> > The message was checked by ESET NOD32 Antivirus.
>
> >http://www.eset.com
>
> __________ Information from ESET NOD32 Antivirus, version of virus
> signature database 5716 (20101219) __________
>
> The message was checked by ESET NOD32 Antivirus.
>
> http://www.eset.com

Don't give the electronic flow type varios too bad a rap. In my
opinion the Cambridge MNAV vario was very good. Of course the glide
computer became obsolete when GPS arrived on the scene.

Andy

__________ Information from ESET NOD32 Antivirus, version of virus signature
database 5718 (20101220) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com





__________ Information from ESET NOD32 Antivirus, version of virus signature database 5718 (20101220) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com