United States Department of Agriculture

Forest Service

24U~ 0224-23 1 l-MTDC

racking the temperature of tree seedlings from the

nursery to the planting site can be the key to evaluating possible physiological causes of morality

after seedlings are planted. Seedlings enter and

leave nursery storage with easily documented levels of

cold hardiness, root growth potential, and general stress

tolerance (Burr 1990: Ritchie and Tanaka 1990). The

temperatures to which seedlings are exposed after

leaving the nursery, and the duration of the exposure,

can dramatically alter these levels. The effects may be

direct, affecting tissue viability, or indirect, affecting

respiration, transpiration, and plant-water relations.

Environmental conditions seedlings experience must be

measured to determine how those conditions may have

altered seedling physiology and affected outplanting

survival and performance. Temperatures can be measexpensively with the Thermochron

r manufactured b

Dallas Semiconductor Corp.

4401 South Beltwood Parkway

Dallas, TX 75244-3292

Phone: 972-371-6824

972-371-3715

site: http://www.ibutton.com/

The Thermochron iButton is a digital temperature recorder

in a small, 17.35 millimeters eters

thick (0.68 by 0.27 inches), durable, waterproof, stainlesssteel case (figure 1)” it can communicate with a computer

after it has been inserted into a receptor (Blue Dot

receptor, serial port, part number DSI 402DDR8, $5)

with an RJ-11 (telephone) connector that is inserted into

a standard nine-pin CO port adapter (universal serial

port adapter, part number DS9097U-9, $10) that plugs

into the computer’s serial port. These items can be

purchased as a starter kit (part number DSl921 K, $25).

Additional Thermochron iButtons (part number DSt921

L-F5x) can be purchased. Each jButton has a unique

64-bit identification number. Accessories can attach

jButtons to almost anything (for example, a plastic flanged

key fob, part number DS9093F, $0.80, see figure 1).

The ‘jE3utton viewer’ software, needed to program Thermochron @r-&tons and review data, can be downloaded

free from the Dallas Semiconductor Web site (http://

w~w,;button.com/software/fhermochron/index.htm~.

The software can be installed on computers running

Windows 2000,98,95, or NT.

Figure l-The Thermochron iButton data logger with hardware that

allows it to communicate with an IBM-compatible computer.

: Andy Treni, Project Leader, USDA Forest Service, MIDC; 5785 Highway 10 West; Missouk~,

MT 59808. Phone: 406.-329-3912; Fax: 406-329-3719; E-maii: atrent@fs,fed,us
The digital thermometer measures tern

-40 to -1-85 “C (-40 to +I85 “F) in I “C

an accuracy of fl “C. real-time clock calendar is

accurate to f2 minutes per month ithin a 0 to 40 “C

range. The recording interval can ge from 1 to 255

minutes in 1 -minute intervals, with a starting offset of 0

t each recording i

the date, time, a

m of temperature values;

I time, and duration of

up to 24 temperature events o e a range of selected

points. After 2,048 time-sta

term monitoring data can be record

The histogram has 63 data

ower source

is about 1 million measurements or

enhanced graphic

Download the ton viewer software from the Dallas

Semic ite: htt~://www.ibutton.co

softwa

Runtim~ Environment Install for 32-

(Version 3.12) (Y2

e. Save

hard drive.

left mouse button to install the software on your computer.

The default install location C:~~~ogra~ FilesID

Se~;con~ucto~. Start the i tton viewer from th

dows ‘Start’ button on the bottom I the computer

screen: ‘Start > Programs > @&ton- X.’ The jButton

viewer ‘Help’ file is installed at the same location.

The iButton viewer’s mai

cation number (ending in

and the identification number

with which Therbutton and seeing

which number disappears. Click the Thermo~hron i

number to select it. Then click the ‘Click Here for

box in the lower right corner of the indow and select

ermochron viewer win

rd’ tab to program a

orward and takes only

a minute. Successive windows will prompt you to set

the Thermo~hron time from the computer clock, set the

set here. The dro~down ‘Options’ menu o

a can be conveyed from one scale to the

Stored data can be saved during or after a

missio selecting sults,’ the second of the

s on the Thermo~hron viewer window. The

tores three types of data: tern

histogram. The ‘Temperature

presents the starting and ending date and time of temperatures outside the high and low alarm limits. The ‘Log’

window displays the date, time, and temperature of the

2,048 time-stamped measurements. The Wistogram’

window lists the 63 histogram bins and the count of data

in each bin.

Viewing options not only change the display, but also

e export format of the data. Options include

changing the date and time to the number of minutes

since the start of the mission, a cribing histogram

bins in different ways: by bin n by the range of

temperatures within the bin, or by the starting temperature.

option available on the drop-down ‘Option’

ow F/C on Temperatures,’ adds or removes

om the log and histogram data. Removing

the units can make it easier to graph the data in another

software package. The numerical temperature and the

alphanumeric unit are assigned to the same co

delimited data field when the data are exported.

ata sets can be graphed at the

Its’ window quickly with just the push of a

button. This option makes it easy to scan the data for

any deviations from expected temperatures. Although

viewer software has no edit or print options

aphs, the data can be exp

imposed into another soft

printing.
Data can be exported to a text file with a .txt extension

by clicking the ‘Export’ button in the ‘Mission Results’

window. Mission status information is exported in a tabdelimited sentence structure. The actual logged data

follows in a comma-delimited format. To open the text

file from within Microsoft Excel, for example, use the

‘Text Import Wizard’ in Excel. Select ‘Delimited,’ both

‘Tab’ and ‘Comma,’ and ‘General’ as each question is

asked. Once the data are in the spreadsheet, a chart

can be designed to suit your needs. A second method

can be used to transfer the data to another program. The

data can be copied to the Windows clipboard and pasted

from the clipboard into another software package, such

as Microsoft Word. This file can be saved with a ‘.doc’

extension. This is a quick way to get a hard copy of the

raw data. The jButton viewer software ‘Copy Export Data

to Clipboard’ option is in the ‘File’ dropdown menu on

the top menu bar.

issii S

The ‘Status’ tab is the third tab on the viewer window.

Thermochron jButtons can be snapped into the Blue Dot

receptacle and checked at any time without disrupting

a mission. Information provided includes: current and

starting date and time, whether the mission is in progress,

the sample rate, whether data has been overwritten, the

start delay, the number of samples taken in the current

mission, and the total number of samples taken during

all missions. When data are exported, this information

is included at the beginning of the file.

The option to stop the current mission is the last item on

the ‘Options’ dropdown menu on the menu bar. The

data remain stored even after the mission has ended.

The data continue to be stored until the iButton is reprogrammed. Make sure that data have been exported

successfully before reprogramming the iButton.

A sample data set was recorded by placing a Thermochron iButton in a shipment of seedlings sent from the

Colorado State Forest Service Nursery at Fort Collins, CO,

to the USDA Forest Service, Rocky Mountain Research

Station in Flagstaff, AZ. Twenty-three seedlings left the

nursery in the nursery’s standard heavy paper shipping

bag at noon on May 22, 2000, in the private mail carrier’s

van that typically delivers trees. Temperature measurements were logged every 30 minutes until the trees

arrived at the research station in Flagstaff at noon on

May 25. The data were exported to Microsoft Excel and

the jButton viewer software log and histogram graphs

were recreated (figures 2 and 3).

The seedlings left nursery storage at 3.5 “C (38 “F) at

time = 0 hours (figure 2) and quickly rose to 34 “C (93

“F) the afternoon of May 22. This is much too warm for

packaged dormant tree seedlings. Tree temperature

dropped to about room temperature (21 “C, 70 “F) during

the evenings, but continued to approach 30 “C (86 “F)

or 35 “C (95 “F) each afternoon. At noon on May 25

(time = 72 hours), the package entered the temperaturecontrolled Flagstaff off ice complex and returned to room

temperature. The histogram (figure 3) of the frequencies

of temperatures in 2 “C intervals provides an indication

of the relative amount of time spent at the various temperatures. For about half the trip the trees were at temperatures greater than or equal to 26 “C (79 “F). Nurseries

shipping trees through the mail can easily conduct similar

tests to assess the insulating ability of their packaging

materials and the temperature stresses trees encountered

during shipping.

The Thermochron iButton, manufactured by Dallas Semiconductor, has features that make it ideal for a recording

device to monitor tree seedling temperatures from nursery

production to outplanting: reliability, weather resistance,

a wide temperature range, ease of use, and minimal

expense. Nurseries and field units receiving seedlings

should find that this device could help determine whether

temperatures during shipping have affected tree survival

and performance.
o 25

f

5

f

2 0

t?

g 15

10

0 6 12 18 2 4 3 0 3 6 4 2 4 8 5 4 6 0 6 6 7 2

Time (hours)

Figure 2-An Excel recreation of the iButton viewer’s log graph of time-stamped data gathered while seedlings were shipped from the Colorado State Forest Service Nursery at Fort Collins, CO, to the Rocky

Mountain Research Station, in Flagstaff, AZ.

Temperature “G

Figure 3-An Excel recreation of the iButton viewer’s histogram graph of time-stamped data gathered while

seedlings were shipped from the Colorado State Forest Service Nursery at Fort Collins, CO, to the Rocky

Mountain Research Station, in Flagstaff, AZ.
The authors thank Randy Moench, manager of the Colorado State Forest Service ursery, and Jim Barnett,

USDA Forest Service, Southern Research Station,

Pineville, LA, for helping test this product.

Burr, K. E. 1990. The target seedling concepts: bud

dormancy and cold hardiness. In: Rose, R.; Campbell,

S. J.; Landis, T. D.; eds. Gen. Tech. Rep. R

seedling symposium: proceedings: combined meeting

of the Western Forest Nursery Associations; August

13-l 7, 1990; Roseburg, OR; Fort Collins, CO: USDA

Forest Service, Rocky Mountain Forest and Range

Experiment Station: 79-90.

Ritchie, G. A.; Tanaka, Y. 1990. Root growth potential

and the target seedling. In: Rose, R.; Campbell, S. J.;

Landis, T. D.; eds. Gen. Tech. Rep. RM-200. Target

seedling symposium: proceedings: combined meeting

of the Western Forest Nursery Associations; August

13-17, 1990; Roseburg, OR; Fort Collins, CO: USDA

Forest Service, Rocky Mountain Forest and Range

Experiment Station: 37-42.

a has a B.S. degree in electrical engitana State University. He joined the

Missoula Technology and Development Center in 1969

and worked on a wide variety of projects before retirin

in 2001. Electronic devices he designed have saved

Forest Service nursery workers hours of backbreaking

labor. He has been awarded one patent and has another

pending.

urr is a horticulturist at the USDA Forest

Service Coeur d’Alene Tree Nursery overseeing seed

and seedling quality activities. She was formerly a research plant physiologist at the Forest Service Rocky

Mountain Research Station in Flagstaff, AZ. She received

her Ph.D. in ho~iculture from Colorado State University.

s was a USDA Forest Service plant

physiologist from 1968 to 2001, He worked for the Rocky

Mountain Research Station, initially in Bottineau, ND,

and then in Flagstaff, AZ. In 1996, Dr. Tinus transferred to

the Southern Research Station to serve as a national

nursery consultant. He is perhaps best remembered for

his groundbreaking work in greenhouse container tree

seedling production and his dedication to technology

transfer in the United States and abroad.

Andy Trent is a project engineer at MTDC. He received

his bachelor’s degree in mechanical engineering from

Montana State University in 1989. Before coming to

MTDC in 1996, Andy worked as a civilian engineer for

the Department of the Navy. Andy works on projects in

the nurseries and reforestation, forest health

protection, and watershed, soil, and air programs.
Gasvoda, David S.; Tinus, Richard W.; Burr, Karen E.;

Trent, Andy. 2002. Monitoring the temperature of tree

seedlings with the Thermochron iButton data logger.

Tech Tip 0224-2311 -MTDC. Missoula, MT: U.S. Depat-tment of Agriculture, Forest Service, Missoula Technology

and Development Center. 6 p.

Thermochron jButton data logger, manufactured by

Dallas Semiconductor Corp., measures temperatures

in increments of 1 “C with an accuracy of +1 “C. The

real-time clock calendar is accurate to 7t2 minutes per

month within a 0 to 40 “C range. The recording interval

can range from 1 to 25.5 minutes in l-minute intervals,

with a starting offset of 0 minutes to 46 days. After 2,048

Describes the use of a small (Y4- by ‘/,-inch), durable

data logger to record the temperatures to which tree

seedlings are exposed when they are transported from

the nursery to the planting site. Seedlings enter and

leave nursery storage with easily documented levels of

cold hardiness, root growth potential, and general stress

tolerance. The temperatures to which seedlings are

exposed after leaving the nursery, and the duration of

the exposure, can dramatically alter these levels. The

time-stamped temperature values have been logged,

recording stops or values are overwritten (depending on

the alternative selected). Nurseries and field units

ceiving seedlings should find that this device could

determine whether temperatures have affected tree

survival and performance.

Keywords: nurseries, shipping, transportation

ent e

USDA Forest Service, MTDC

5785 Highway 10 West

Missoula, MT 59808-9361

Phone: 406-329-3978

Fax: 406-329-3719

E-mail: woomtdc-pubs@fs.fed.us

ctro

eon

http://fsweb.mtdc.wo.fs.fed.us

ilPhone: 406-329-3912

Fax: 406-329-3719

E-mail: atrent@fs.fed.us

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