Friday, July 15, 2005

Brass balls

Link: Liberty Brass

In the field we use brass balls (painted black) to hold our iButton temperature loggers. It's meant to be a modular solution for instances where you already have lots of 1/2" PVC couplers mounted on the shore from other projects. The round brass ball provides a constant projected surface area facing the sun for almost any direction, which means you can rely on having consistent, standardized exposure as the sun moves through the sky. We ordered our balls from the Liberty Brass site linked above. They are willing to drill and put threads in the balls (if you order enough to make it worth their while) so that you can easily mount the balls on 1/2" PVC fittings.

The appropriate size to order is the 1.25" ball, but with a special order 1/2" NPT Pipe thread tapped into it. This allows room for the ibutton to fit inside the ball, and allows you to screw in standard PVC fittings. They don't seal completely watertight, but iButtons tend to hold up fairly well even when submerged in salt water for a month or two.

Tuesday, July 12, 2005

Impact factor

For future reference, to look up the impact factor of a journal, try this link ISI Journal Citation Report. It's a subscription based service, so you'll need to go in via an institution with a subscription.

Thursday, July 07, 2005

iButton Nirvana!

If you use a lot of iButton temperature loggers on a regular basis, you might want to download one of these macros that Luke Hunt has made available. The first is an Excel macro/script that pulls out the date/time and temperature data from text files created by Dallas Semiconductor's iButton Viewer program. It strips off the histogram data, the header information, and all that gobbledeegook at the end of the text file, and just puts two columns of data into your Excel spreadsheet. You can obviously do this manually by cutting and pasting, but if you've got a system set up with a bunch of iButtons that all get downloaded and processed at the same time, this macro is a real timesaver. The second macro Luke Hunt provided will do much the same thing, but it will pull data saved on Palm handhelds, if you download your iButtons in the field. That one is a Matlab .m file.

Check them out at Luke Hunt's file page

Also take some time and persue Luke Hunt's homepage and the rest of the Denny Lab website at