Paul, while I can't help with current pricing here is some `canned' info
that I've saved from previous projects:

   Philips makes a low-cost sensor (P/N 2322 691 90001). General Eastern also
seems to have interesting low-cost sensors in their G-CAP line. Their sensors
cover 1 - 100% RH.

   For my project, I needed better accuracy and I wanted to reduce the
complexity of the support circuitry. I ended up 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 1 - 100% and provide an output from around 0.8V - 3.9V with a 5V
supply. They should be buffered and 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 sensor. You normally combine both in a package for your
outdoor sensors.

   For more info, contact:

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

   - Tom

At 07:12 AM 5/18/98 -0600, you wrote:
>Hi,
>Awhile ago there was a thread on humidity sensors. One of the
>recommended vendors was Panametrics with their RH2 sensor. This is
>supposedly a low cost humidity sensor. However, their "sampling" program
>is to sell me 3 for $100US. This hardly qualifies as low cost or
>sampling. Does anyone have any other sources for a humidity sensor or
>better yet a way to build your own?
>
>Thanks,
>Paul K.
>
>PS I will be interfacing this to a PIC. So it is not quite OT.
>
>