×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

thermocouple aray, thermal conductivity of snow

thermocouple aray, thermal conductivity of snow

thermocouple aray, thermal conductivity of snow

(OP)
I am trying to build a temperature probe to measure snow temperatures.  I already have the wire picked out, but I am looking for a material to use as the holder.  It will be mostly in the snow, but 5-10cm will be out of the snow and I don't want them to heat up with solar radiation.  Can anybody tell me a material that will work best the thermal conductivity of snow is 0.6000 W/m*C

RE: thermocouple aray, thermal conductivity of snow

Hi clouddancer,
If you want to know the surface temperature of the snow, a pyrometer would do the best, fast and reliable. You need to know the radiation coefficient of snow/ice.
Wood, especially light wood like Balsa, has <0.2W/(m*K), glass has 0.6-0.9W/(m*K). Maybe, carbon fibre has a low thermal conductivity, in addition to it's high stability, but pure graphite has 140W/(m*K). An alloy, in Germany called "Neusilber" (German silver, Nickel silver, Pakfong), has 29W/(m*K). It is relatively hard, you can buy very thin pipes as laboratory equipment.
Another solution is to put the sensor nearly horizontal into the snow, to guarantee a long thermal way for the sunlight induced heat.
tiki

RE: thermocouple aray, thermal conductivity of snow

Instead of thermocouple use thermistor -- its higher resistance can tolerate thinner/longer wire.

<nbucska@pcperipherals.com>

RE: thermocouple aray, thermal conductivity of snow

Hi nbucska,
if you measure the thermocouple induced voltage with a relatively high impedance, the impedance of the wires will be neglible, and it will not self-heat. But the small voltages may require a preamplifier with very good dc-performance (chopper).
tiki

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

White Paper – Data Security and Know-How Protection
Our data is constantly exposed to the danger of being intercepted or stolen as it wends its way over global data networks. Data security measures and measures for protecting intellectual property should not, however, first be implemented when data is exchanged – companies must lay the foundation for these measures within their own organization. Download Now
White Paper – Collaboration in the PLM Context
The influence exerted by the Internet of Things (IoT) means that there is a steadily growing need for collaboration in industry. Partners from new industries and areas of application need to be integrated in cross-company business processes to ensure that the lifecycle of smart, connected products can be managed from end to end. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close