Searching \ for 'humidity and barometric sensors' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page:
Search entire site for: 'humidity and barometric sensors'.

Truncated match.
PICList Thread
'humidity and barometric sensors'
1997\08\30@182707 by Eric van Es

Harrison Cooper wrote:
> I was looking thru all my old mail, and thought I had seen some
> information on these types of sensors.  I believe that motorola makes
> some barometric sensors, but what about humidty ?  any website pointers
> would be appreciated.

Sure, try:
-- Chip Directory
-- - USA
-- - Netherlands
-- And many other international mirror sites.
-- Test versions:
-- - Test Version
-- - New in Australia!
-- - New in the USA!
-- - New in the USA!
-- - New in Greece!
-- Free chip questions mailing list, send an email to
-- With in the body:
--   subscribe chipdir-L

I don't promise success as I rarely need the site, but I am subscribed
to the list and this might a good place to ask.

good luck (or break a leg if you are superstitious :-) )

Eric van Es               | Cape Town, South Africa |

1997\08\31@092203 by Tom Handley

picon face
At 07:12 AM 8/29/97 -0600, Harrison Cooper wrote:
>I was looking thru all my old mail, and thought I had seen some
>information on these types of sensors.  I believe that motorola makes
>some barometric sensors, but what about humidty ?  any website pointers
>would be appreciated.

  Harrison, Low-cost sensors behave like capacitors that vary with humidity
to change the frequency of an external oscillator. Typical relative humidity
ranges from 10 - 90%. Philips makes a low-cost sensor (P/N 2322 691 90001).

  For my project, I needed better accuracy and I wanted to reduce the
complexity of the support circuitry. I ended using HyCal sensors which
provide an output within 0-5V and require minimal support. The outdoor
sensor is an IH-3602L which comes in a T0-39 can with a slotted cap and for
the indoor sensor, I used the IH-3605 hybrid element. Both sensors operate
from 0 - 100% and provide an output from around 0.8V - 3.9V with a 5V
supply. They require a simple low-pass filter and, as with most sensors,
need to be shielded from sources of bright light. You do need to factor in
temperature compensation so you need to measure ambient temperature near the

  For barometric sensors, I use a 0 - 15psi pressure sensor. Motorola and
Sensym have low cost sensors. I have a pic 16C74-based weather station that
uses the Sensym SCX15ANC temperature-compensated sensor and I've had
excellent results over the last year. I use a 10V reference to supply the
bridge excitation voltage and I connect the output to an Analog Devices
ADC620 instrumentation amp with a gain of 50. That goes to a 12-bit A/D with
a span of 0 - 4.096V. I scale and offset the data in software. The A/D is a
MAX186 which has 8 channels and an SPI interface.

  For more info, contact:

     Humidity Sensors:
     HyCal          : (818) 444-4000
     Philips        : (817) 325-7871
     General Eastern: (800) 225-3208

     Pressure Sensors:
     Sensym  : (408) 954-1100

  - Tom

'humidity and barometric sensors'
1997\09\02@124419 by lilel
Ranish said:
> I use the Philips H1 capacitive Humidity Sensor. I could not locate
> it on their site (maybe they forgot to put it there ! ) It is fairly
> linear and quite stable in its response.

Got any cost numbers?

Best Regards,

Lawrence Lile

More... (looser matching)
- Last day of these posts
- In 1997 , 1998 only
- Today
- New search...