AnsweredAssumed Answered

vrf Measuring pressure, temperature, humidity

Question asked by VRFuser on Apr 8, 2008
We are using a Honeywell sensor that is differential plus 1" of water to minus 1" of water.  The dcvolts out is being read by an Agilent 34970a and then into VEE.  We are also reading Omega thermalcouples J type also into the 34970a.

-----Original Message-----
From: B Walden [mailto:bwalden@whoi.edu]
Sent: Tuesday, April 08, 2008 8:49 AM
To: VRF
Cc: VRF
Subject: Re: [vrf] Measuring pressure, temperature, humidity

Hi Abe,

I've done a lot of this and have tried many possibilities. As mentioned by Achim and Stan, both Vaisala and Oregon Scientific make suitable sensors. The Vaisala WXT510 is a combination meteorological sensor that provides temperature, barometric pressure, humidity, and rain fall. Its available in both RS232 and RS485 models. I've used it with Vee without difficulty, including its automatic configuration and subsequent logging of it's configuration (automatic configuration has a few rough spots however). This instrument is fairly large and expensive.

Another approach (particularly for temperature) is to purchase the analog sensors of your choice and couple them with suitable interface adapters.  I have used adapters manufactured by DGH (www.dghcorp.com) and also marketed by Omega and Keithley (perhaps discontinued by Keithley). These work extremely well, provide an 232 or 485 interface, and are easy to use with Vee.

Barometric pressure sensors can be hard to find - Honeywell makes one that's small, accurate, easy to use, and available with various serial interface options. The TTL interface model (which you probably don't
want) is HPB200WTTA-H020; this should get you to the right place on their web site - I believe 232 and 485 are available.

Finally, I have recently tested an Omega i.BTHX. This sensor group provides temperature, humidity, dewpoint and barometric pressure in a package about twice the size of a package of cigarettes (cost ~$250.00).  Unfortunately, the interface is via a number of different network connection methods; no simple serial. I've used it with Vee and a third party TCP/IP ActiveX object but I'm quite sure it will work with a Vee socket. It can provide data continuously or on demand. Initially I had a problem that appears to have been caused by a bug in the firmware.
They updated this firmware and I haven't seen the problem since - new version is Ver 1.6B. [Bug - if the sensor module received a "bad" data request, it continuously output a stream of "serial timeout messages"
that could only be stopped with a power reset.]  If you try one of these and have problems, my point of contact was  Lus Rondon, LRondon@newportus.com.

Barrie
whoi


abep@lonestar.utsa.edu wrote:
> Hello all,
>
> Just wondering if anyone currently uses any hardware that works well
> with VEE that can measure room pressure, temperature and humidity.
> I've mostly searched the Agilent and Fischer Scientific site and found
> nothing yet.  Thanks!
>
> Abe
>
>
>
> ---
> You are currently subscribed to vrf as: bwalden@whoi.edu To subscribe
> please send an email to:
> "vrf-request@lists.it.agilent.com" with the word subscribe in the
> message body.
> To unsubscribe send a blank email to "leave-vrf@it.lists.it.agilent.com".
> To send messages to this mailing list,  email "vrf@agilent.com".  If
> you need help with the mailing list send a message to
> "owner-vrf@it.lists.it.agilent.com".
> Search the "unofficial vrf archive" at
> "http://www.vrfarchive.com/vrf_archive".
> Search the Agilent vrf archive at "http://vee.engineering.agilent.com".
>



---
You are currently subscribed to vrf as: henry.coles@hp.com To subscribe please send an email to: "vrf-request@lists.it.agilent.com" with the word subscribe in the message body.
To unsubscribe send a blank email to "leave-vrf@it.lists.it.agilent.com".
To send messages to this mailing list,  email "vrf@agilent.com".
If you need help with the mailing list send a message to "owner-vrf@it.lists.it.agilent.com".
Search the "unofficial vrf archive" at "http://www.vrfarchive.com/vrf_archive".
Search the Agilent vrf archive at "http://vee.engineering.agilent.com".



---
You are currently subscribed to vrf as: ming_meng@agilent.com To subscribe please send an email to: "vrf-request@lists.it.agilent.com" with the word subscribe in the message body.
To unsubscribe send a blank email to "leave-vrf@it.lists.it.agilent.com".
To send messages to this mailing list,  email "vrf@agilent.com". 
If you need help with the mailing list send a message to "owner-vrf@it.lists.it.agilent.com".
Search the "unofficial vrf archive" at "http://www.vrfarchive.com/vrf_archive".
Search the Agilent vrf archive at "http://vee.engineering.agilent.com".

Outcomes