IC's to measure barometric pressure

[Paul Marcel]

Are there any?

 

[Tim Wescott]

Paul Marcel wrote:

Are there any?



Motorola made absolute pressure sensors, probably went to Freescale.

Other companies undoubtedly do, too. They probably aren't accurate
enough for a barometer, but who knows?

Google on "MEMS" and "pressure sensor" and you should turn something up.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Nicholas O. Lindan]

"Tim Wescott" <tim@wescottnospamdesign.com> wrote

Motorola made absolute pressure sensors, probably went to Freescale.
Other companies undoubtedly do, too. They probably aren't accurate
enough for a barometer, but who knows?

They can be linearized in software. The problem is temperature
compensation: they often make better thermometers than barometers.

TC'd units are available (and the only way to go for making a barometer),
if the environment is household indoors I am sure one would work fine.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/

 

[Rich Grise]

On Wed, 01 Dec 2004 09:22:48 -0500, Paul Marcel wrote:

Are there any?

Yes.

http://www.google.com/search?&q=IC%27s+to+measure+barometric+pressure&btnG=Google+Search

Good Luck!
Rich

 

[Roger Hamlett]

"Paul Marcel" <paulmarcell@charter.net> wrote in message
news:1rkrq0ppnqh2s8e4vhavu6cvddfj1obpv1@4ax.com...

Are there any?
Do a search on the MPX2100.

This was the original Motorola sensor family (now made by Freescale), and
are quite good _provided they are fed with a accurate reference, and high
quality op-amps are used for the amplifier_. These units are largely
temperature compensated (a big advantage). Honeywell do a more accurate
sensor, but the price goes up proportionately. The full scale, still
changes by +/-1% with temperature, and if you want to get the best
accuracy, tweaking for this is worthwhile.

Best Wishes

 

[Spehro Pefhany]

On Wed, 01 Dec 2004 09:22:48 -0500, the renowned Paul Marcel
<paulmarcell@charter.net> wrote:

Are there any?

Here's one that's exceptionally easy to use (built-in 14-bit ADC and
serial synchronous or asynch comms):

http://www.allsensors.com/datasheets/app_specific/14bit_dig_baro_ind.pdf

It's available at Digikey (not cheap, though).


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Jonathan Kirwan]

On Wed, 01 Dec 2004 09:22:48 -0500, Paul Marcel <paulmarcell@charter.net> wrote:

Are there any?

Interesting reading the other responses. Another question is to what precision,
I suppose. I've built my own with the ability to detect changes in altitude of
50cm out of an empty spray can, some glass tubing, two LEDs, some nichrome wire,
a tiny circuit and power supply, and some DOT brake fluid. Cheap and sensitive,
but it won't work upside down!

Jon

 

[YD]

On Wed, 01 Dec 2004 17:55:52 GMT, Jonathan Kirwan
<jkirwan@easystreet.com> wrote:

On Wed, 01 Dec 2004 09:22:48 -0500, Paul Marcel <paulmarcell@charter.net> wrote:

Are there any?

Interesting reading the other responses. Another question is to what precision,
I suppose. I've built my own with the ability to detect changes in altitude of
50cm out of an empty spray can, some glass tubing, two LEDs, some nichrome wire,
a tiny circuit and power supply, and some DOT brake fluid. Cheap and sensitive,
but it won't work upside down!

Jon

I'd love to see that one. Is there a description and diagram on-line
somewhere?

- YD.

--
Remove HAT if replying by mail.

 

[crzndog]

Thinking aloud here (please don't flame me for this).

If one had mercury in a vessel, wouldn't the resistance change with pressure
(since the molecules are being compressed together under higher pressure).
If so, could you measure that difference to provide an accurate mmHG
reading.

Just a thought.

Also, I'm sure you could use a laser reflected also to get very accurate
measurements (especially if a mirror was floated on the surface of the
mercury).

I don't know how the industial grade Barometric sensors work so please
forgive me if I've stated the obvious.


"Paul Marcel" <paulmarcell@charter.net> wrote in message
news:1rkrq0ppnqh2s8e4vhavu6cvddfj1obpv1@4ax.com...

Are there any?

 

[Keith Wootten]

In message <Xns95B319F4CA77soonerboomergbronlin@68.12.19.6>, Dan Major
<nospam@this.address> writes

<snipped.

And an interesting idea. Except that fluids in general, and mercury (a
liquid metal) are *mostly* incompressible.

ITYM 'liquids'.

Cheers
--
Keith Wootten

 

[Mitch]

http://www.hobby-boards.com/1wireboards/bb4-r3_bray_barometer.html

If you're into 1-Wire...

Works well with http://www.midondesign.com/TEMP08/TEMP08.html


"Paul Marcel" <paulmarcell@charter.net> wrote in message
news:1rkrq0ppnqh2s8e4vhavu6cvddfj1obpv1@4ax.com...

Are there any?