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Final Report
The PIT students have done a great job in the design and construction of the sensor's stands, and picking and documenting the rational behind the placement of the stations on campus.
They have written an excellent 42 page report which we would be happy to send to anyone interested, and will be uploaded on the blog site. All the component parts of the metal stands are now ready for assembly.
The assembly task is not insignificant, probably on the order of 2-4 hrs/station.
Posted by Guillermo Barrenechea at 14:21
Sensor Presentations
Here is the summary of the sensors as presented by the participants of the "Projet Interdisciplinaire de Terrain" (PIT).
Posted by Wolf Hendrik Huwald at 19:14
The Davis anemometer seems to be the most economical that I can find with a wire on it. Please see the attached file for standard price and website (US$120). I have not attempted to call them for a bulk price.
Posted by John Selker at 15:07
IR sensors
Below is the quotation I received. To obtain sample units we need to provide a pre-paid shipping number. The TN0am has easier interfacing, and slightly better accuracy. I think we should get 120 or more since we may need to play with these a bit.

Dear John:

Here are the prices quoted again. by the way, we are willing to send you the modules for test, pls kindly provide the courier account to deliver, and if you dont have any courier account, the fright charge to Swissland is USD 105. Pls kindly let us know how can we deliver the samples to you.

thank you for your kind inquiry, pls be advised that we suggest you chooseTN0pm2: 110 degC coz the size is smaller and more compact,?200 pcs is USD 10.5 but 300 pcs is only USD 6.5 FOB SHANGHAI, much more competitive price if you get 300 pcs per shipment,?TN0am: 220 degC,200 pcs is USD 14 but 300 pcs is only US11.9 FOB SHANGHAI

Thank you very much and any questions are welcomed at all times.

Marketing and Sales dept.
Sharon Wei ???
1F no.3, Industrial E 9th RD,
Science-based Industrial Park,
Hsin Chu Taiwan 300 ROC
TEL: 8863 6111666 EXT 335
FAX: 8863 5644170

http://www.ZyTemp.com <http://www.zytemp.com/>
http://www.radiantek.com.tw <http://www.radiantek.com.tw>
Posted by John Selker at 14:47
Soil pressure with moisture point
The watermark sensors will be employed on at 60 of the EPFL units (those over soil). They cost about $25 ea. The exclusive Swiss dealer is Challenge Agriculture S.A.R.L. http:www.terre-net.fr/cha.

See page 5 of the attached manual to get brief details on reading with a datalogger. It appears that the reading should be and AC resistance measurement which will expect from 500 to 30,000 ohms.
Posted by John Selker at 14:42
Echo Soil moisture probes
Here are the specs on the Echo soil moisture probes. I think we deicde on 60. I don't have a hard quotation, but I think they will be between 50 and 60US$ Please order the 10 cm version.
Posted by John Selker at 14:33
Comments (1)
tipping bucket rain gauges
The La Cross model seems the best buy at $25. Ironically it is made in France, but they are out of stock. The attached file indicates a US source that has 100 on hand. Also ironic is that it comes with the nifty digital display which we will simply cut off and throw away. I called La Cross, and they were not interested in selling us 100 units without the display.

The Davis unit is also fine, but costs 3x as much.

In either case, we will need to record tips in time. This is a bit cahllenging perhaps, since they come at irregualr intervals. Is htis feasible in low-power mode of operation? The device itself takes no power, with output being from a Hall-effect switch.
Posted by John Selker at 14:31
Meeting 15/9
Present: john selker, marc parlange, EFLUM guest (jan?), hendrik, luciano,
guillermo, luciano, laurent, henri

Topic: shopping list for oct 31 budget

We agreed on the following list:
[ ouch, formatting is messed up, but i've attached the spreadsheet]

quant unit total
tinynode 115 180 20700
solar board components 115 60 6900 [only parts, no battery, no panel]
oscilloscope 1 3000 3000
solar radiation sensor 115 100 11500 [davis model ??]
skin sensors 115 25 2875 [zytemp TN0am]
rh/temp sensors 115 45 5175 [sensirion sht 75]
soil moisture sensors 60 45 2700
soil moisture sensors 60 100 6000 [decagon model ??]
precipitation 115 100 11500 tipping bucket

70350 (CHF)

If i forgot anything please let me know.

The cost numbers for many items above are approximate. So next step is to
obtain firm quotes for each one. EFLUM does the sensors, LCAV does the
hardware. Once the numbers come in, we recalculate and if we are still
above 50KCHF we will see which sensors we postpone to year end.

Posted by Henri Dubois-Ferriere at 23:39
T and RH
The GE RH sensors are not capacitive type and should not get condensation (as mentioned in the specs), so they are out.
the Smartec ones seem to be the better (if we believe the specs) , more expensive option.
While the sensirion seem to be the cheaper option.
The smartec are also mounted on chips so we buy them and plug them. No advantage for sensirion on that end.
Posted by Elie Bou Zaid at 18:19
these are the specs on the devices that we will use for the raingauge-air speed sensors
Posted by John Selker at 15:37
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