Naoya, No, they are basically watch batteries with integrated circuits and a thermocouple attached and sealed inside a stainless steel cup.
I have used them with some success however they are far from waterproof if submerged more than a few inches. I recently constructed a plexiglass housing for them which I then filled with silicone caulk. This arrangement survived 6 months buried in Antarctic tundra over- winter. Here's a photo: Apologies for ECOLOGERs but the list does not allow attachments. I would be happy to send the photo to anyone off-list on request. David M Bryant Ph D University of New Hampshire Environmental Education Program Durham, NH 03824 [EMAIL PROTECTED] 978-356-1928 On Feb 9, 2006, at 2:51 PM, Naoya Nishimura wrote: > Hi.. > > Great summary on the different loggers.. > > Do you know if the iButton batteries can be replaced? I currently > have Hobo > Pro Series Temp/RH units which costs in the 150 zone with user > replaceable > batteries. Its a good unit but out of 24 that I currently have, I > had to > send 5 back to get the Humidity sensor fixed which by the way cost > 48 bucks > a unit. > > I like the smaller size of the iButton but at a price near 100 > bucks unit, I > think the Hobo units are better if iButton doesnt have the user > replaceable > batteries. > > See ya, > > Nishimura > > > > ----------- > Naoya Nishimura > University of Florida > Florida Medical Entomology Lab > 200 9th St SE > Vero Beach, FL 32962 > 772-778-7200 x 147 > > -----Original Message----- > From: Ecological Society of America: grants, jobs, news > [mailto:[EMAIL PROTECTED] On Behalf Of S. LaDeau > Sent: Monday, February 06, 2006 2:47 PM > To: [email protected] > Subject: Summary: Temperature/RH data loggers > > Below is a summary of the responses I received regarding monitoring > temperature in the field. > > Hobo Series (the most positive responses): > HOBO Pro Family RH/Temperature Data Loggers (model # H08-032-08): > http://www.onsetcomp.com/Products/Product_Pages/HOBO_H08/ > hobo_pro_family_lo > ggers.html > $135-159 > > These loggers are weatherproof, not waterproof. To protect them > from the > rain (mainly the RH sensor), you can purchase a Rain Shield ($25-30). > > The waterproof versions are too expensive so I make my own waterproof > containers. Just take a little plastic containers with a tight > fitting lid, > drill a hole in the side, run the cable for the thermometer through > it and > seal it with rubber sealant. They work great and are about ½ the > price of > the waterproofed versions. > > The RH sensor can become saturated in extremely wet environments but > saturation can be minimized by using the protective cover. We make > our own > covers using a 4 inch PVC pipe cap found at the local hardware store. > These basically act as a solar and rain shield, but also protect the > logger. > > > built protective covers out of 1 l plastic soda bottles that were > open at > the bottom the protected the loggers from rain and dew. > > HOBO PC compatibility, user friendliness and customer service > were all > regarded highly. > > Ibuttons: > Look into ibuttons by Maxim/Dallas Semiconductors > (http://www.maxim-ic.com/products/ibutton/ibuttons/ > thermochron.cfm). The > data loggers look like large watch batteries, but can collect up to > 1800 > data points in a single collection...The temp data are only > recorded in 0.5C > increments, so if you are looking for something more exact, this > may not be > the way to go. I used them in the field and left them outdoors and > unattended for up to three months at a time. Never had a problem > and they > are very reasonably priced, too. > > i-buttons are a very inexpensive versatile way to measure long term > temperature fluctuations > > Potential availability/backorder issues > > For just straight temperature tracking you can't beat i-buttons > (www.ibutton.com) they can track temperatures for any interval for > long > periods of time (I have them out for a year tracking temperature > every 4 > hours) and last about 10 years before the battery dies. Plus they are > incredibly durable. Half of our ibuttons are under the soil surface > > company is terrible to deal with but otherwise they have been great > > The support at Embedded Data Systems has been fantastic. > > I've been using ibuttons, but they are not waterproof and various > ways of > keeping them dry (placed in plastic bags, painted with liquid > electrical > tape, etc) are problematic. However, they are great temperature data > loggers. They cost about 21$ apiece, and the reader is only 5 > bucks and > plugs into your computer via a USB port > > Price for temp/RH is currently $95.00 (for 10-100 units). 1 week > lag for > order (10 unit) availability. > > > Other recommendations/comments: > I have had good success with ONSET(http://www.onsetcomp.com) > temperature > loggers, currently we are using tidbit loggers (around the size of > a stack > of 8 quarters and ~120$) for water temperature and air > temperature. I > have also used the HOBO (~60$ for logger and ~30 for waterproof case) > logger from onset as well, while these are larger (around the size > of a > coffee mug with waterproof case) you can replace the batteries, > unlike the > tidbits. If you are in a heavily traveled area and might have alot of > loggers stolen, the cheaper of the two would definately be the > HOBOs and > the computer link for the hobo is cheaper versus the optical link > for the > tidbit logger. > > I've had good success with Onset Water Temp Pro loggers but NOT the > Tidbit loggers. I've not tried the newer stainless steel loggers now > available.
