Davis Instruments Leaf & Soil Moisture/Temperature Station, 6343 Installation Manual

WIRELESS L
EAF & SOIL MOISTURE/
EMPERATURE STATION
T
INSTALLATION MANUAL
FOR WIRELESS VANTAGE PRO
The W ireless Leaf & Soil Moisture/Temperatur e Station (referred to in this docu­ment at the Leaf/Soil Station) can be used with any Wi reless Vantage Pro weather station to measure leaf wetness, soil moisture or temperature.
The followi ng Vantage Pro console st ation configu r ations can be use d wit h the Leaf/Soil station:
Station Type in Con­sole Configuration
LEAF/SOIL Station 2 3 3 LEAF Station 2 - 2 SOIL Station - 3 3
• Only one Leaf/Soil Station can be instal led as a Leaf/Soil Station per Van­tage Pro Weather Stat i on.
• Two stations can be installed if one is configured as a Leaf Stat ion and the other station is configured as a Soil Station in the Vantage Pro console.
Number of Leaf
Wetn ess Sen -
sors
Number of Soil
Moisture Sen-
sors
®
Number of
Te mp Probes
• Configured as a Leaf Station, the Station supports two leaf wetness sen­sors and two temperature probes.
• Configured as a Soil Station, it supports up to three soil moisture sensors and temperature probes.
• A Wi reless Soil Moistu re/Temperature Station (#6361) ca n be use d in con­junction with a Leaf/Soil Station if the Leaf/Soil Station is configured as a LEAF station in the Vantage Pro console.
Note: In any sta tio n u s in g so il mo is t u re sensor s, t h e co rr es po nding tem p er a ture pro be , if
installed, will be used for temperature compensation of the soil moisture sensor.
Note: The Leaf/Soil Station requir es Vantage Pro console firmware Rev B or later. (Press
and hold the [D ONE] key then press the [+] (up arrow) key to displa y the console firmware level.) Contact Davis Technical Support for upgrade information.
Product # 6343
Tools for Setup
In addition to the components shown, you will need some or all of the follow­ing materials:
• Adjustable wrench or 7/16" wrench
• Medium Phillips Screwdriver
• Ballpoint pen or paper clip (small pointed object of some kind)
• Drill and 3/16" (5 mm) drill bit (if mounting on a vertical surface)
• Stepped Sensor Installation Tool for Soil Moisture and Temperature Sen­sors (recommened , see page 17)
Components
The Leaf/Soil Station includes the following components and hardware:
Shelter
U-Bolts
1/4" Flat Washers
1/4" Lock Washers
1/4" Hex Nuts
8" Cable Ties
Leaf/Soil Station Components
Optional Sensors
The following optional sensors are avai l able for the Leaf/Soi l Station:
U-Bolts
1/4" Flat
Washers
1/4" Hex Nuts
#8 Flat Washers
#8 Lock Washers
1/4" x 1-1/2"
Lag Screws
3-Volt Lithium
Battery
4" Cable Ties
#8 x 3/4" Machine
Screws
#8 Hex Nuts
Leaf Wetness Sensor
with 40' (12.2 m) of cable
Page 2 Wireless Leaf & Soil Moisture/ Temperature Sta-
#8 Wood Screws
Optional Leaf Wetness Sensor (#6420)
Soil Moisture Sensor
with 15' (4.6 m) of cable
Optional Soil Moisture Sensor (#6440) and Optional Temperature Sensor (#6470)
Temperature Probe
with 15' (4.6 m) of cable
Installation Steps
For ease of installation and u se o f your Leaf/Soil Station, please follow steps in the order pr esent e d.
• Preparing the station, page 4
• Setting the DavisTalk transmitter ID, page 5
• Choosing a location to mount the station, page 8
• Mounting the station, page 9
• Rule s for us i n g the sen s or s , p a g e 10
• Installing leaf wetness sensors, page 11
• Installing soil moisture and temperature sensors, page 13
• Using soil moisture readings, page 18
If you encounter dif ficulti es or have questions ab out your statio n, the following additional information may be helpful:
• Troubleshooting the sensors, pag e 19
• Extending Sensor Cables, page 19
• Contacting Davis Technical Support, page 19
• Specifications, page 20
Installation Steps Page 3
Preparing the Leaf/Soil Station
s
The following illustrations show the location of the DavisTalk transmitter DIP switches, the battery mounting location, the modular connectors used by the leaf wetness sensors, and the terminal blocks used to conne ct the soil moistur e sensors and temperature p robes.
Instal lin g th e Ba tt ery
1. Insert the 3-volt lithium battery into the battery holder, matching t he “+” sign on the battery with the “+” sign next to the ba tte ry mounting brackets.
2. Note the location of the DIP switches. You will work with them during the next installation step.
3-Volt Lithium Battery
DIP Switches
Terminal Blocks
Leaf Wetness Connectors
Installing the Battery
Temporarily Connecting a Sensor for Testing
Temporarily connect at least one of the following sensors.
Note: You m ust have at least one sensor installed in the Leaf/Soil stat ion in order to te st
wireless co mmunications.
Leaf Wetness Sensor Connection
• Connect the leaf wetness sensor cable to the LEAF 1 or LEAF 2 receptacle.
Soil Mo istu re Se nsor Co nnec tion
• Temporarily connect a soil moisture probe to the SOIL 1 terminal block connector.
• Use a pen or sm all scre w d river t o open the connector “jaws” as shown in the illustration.
Connecting a Leaf Wetnes
Sensor
• While the jaws are open, insert the tempera­ture probe leads, then let the connector jaw s close in on the lead.
Page 4 Wireless Leaf & Soil Moisture/ Temperature Sta-
Note: The soil moisture sensor must be moist to be used for this test. A completely dry
r
sens or will not register on the console.
Soil Temperature Sensor Connection
• Temporarily connect a temperature probe to the TEMP 1 termi nal bl ock connector.
• Use a pen or sm all scre w d river to open the connector “jaws” as shown in the illustra­tion.
• While the jaws are open, insert the tempera­ture probe leads, then let the connector jaw s close in on the lead.
Connecting a Soil Moisture o
Temperature Sensor
Setting the Da visTalk Transmitter ID
Each wireless transmitti ng st at ion must be set to one of eight DavisTalk trans­mitter IDs. DIP switches #1, 2 and 3 on the Sensor Interface Module (SIM) allow you to control the ID — the “channel” the station will transmit on. (DIP switch #4 is used for transmission testing, not for transmitter ID.)
Note: A Davi sTalk tr an sm itt er a nd rece iv er c ommun ic at e wi t h eac h o th er o nl y wh en bo th
are set to the same ID.
The factory default transmitter ID is ‘1’. Looking at the table below , you can see that means the DIP switches are in the OFF position when each transmitting station leaves the factory. This is true for all of Davis’ wireless equipment.
1. Veri fy the Dav isTalk channel used by you r ISS, as well as all oth er Davi sTalk channe l s al ready in use by your Vantage Pro Weather Station.
2. Configure the Leaf/Soil Statio n to a DavisTalk channel not already in use.
3. U se a ballpoint pen or pa per clip to t oggle DIP switches #1, 2, and 3. The set­tings for transmitter IDs 1 – 8 are shown in the table below:
ID CODE SWITCH 1SWITCH 2SWITCH 3
#1 (default) OFF OFF OFF
#2 OFF OFF ON #3 OFF ON OFF #4 OFF ON ON #5 ON OFF OFF #6 ON OFF O N #7 ON ON OFF #8 ON ON ON
Setting the DavisTalk Tran smitter ID Page 5
.
Battery Holder
ON
1234
DIP Switches
DavisTalk Transmitter DIP Switches in Top-right Corner of SIM
Setting Console/Receiver(s) to Same ID
1. Put your console into Setu p Mode — press and hold th e DONE key and press the DOWN (-) arrow key.
• The console will show you the words: “RECEIVING FROM...” and “ST ATION NO.” followed by the transmitter IDs that your console detects. One of these should be the ID number you just set on the Leaf/ Soil Station transmitter.
• If you don’t see it, make sure the console is within 10' of the transmitter , and verify that you set the DIP switches correct ly. Wait a few seconds and if you st ill don’t see it , go to “Troubleshooting Communication Prob­lems” on the next page.
2. Press the DONE key to move on to “Screen 2: Selec tin g Transmitte rs .” Setup Mode – Screen 2 is where you will set the console to re cognize signals
on that ID as coming from a Leaf/Soil Station.
3. Pr ess the LEFT (<) or RIGHT (>) ar row key, or the STAT ION key, to scroll through transmitter IDs.
• When you see the ID you chose for the Leaf/Soil Station, use the UP (+) or DOWN (-) arrow keys to activate reception of that ID code. Make sure the screen shows “ON”.
4. Press the GRAPH key to configure the station type in the console. The Leaf/ Soil Station can be configured as a LEAF/SOIL station, as a LEAF station, or as a SO I L s tation .
• Configure it as a LEAF Station if you are only using it for leaf wetness and t e m p.
• Configure it as a SOIL station if you are only using it for soil moisture and t e m p.
• Configure it as a LEAF/SOIL station if you are using it for both leaf wet­ness and soil moisture.
5. To exit Setup Mode, press and hold the DONE key.
Note: See the Vantage Pro U s er’s Manual & Setup Gu ide: “Setup Mo de – Screen 2:
Selecting Transmitters” for more information.
Page 6 Wireless Leaf & Soil Moisture/ Temperature Sta-
Testing Station Communications
1. If you are using a Soil Moisture sensor to test the station, press the TEMP key until you see “SOIL MOIST” displayed on the console screen where the inside temperature is usually displayed. If you are using a Leaf Wetness sensor, press the HUM key u ntil you see “LEAF WET” displayed where you usually see the inside humidity. Both the TEMP and HUM keys will display temperatures if you are using a temperature probe to test the statio n.
• Soil temperature is displayed in the TEMP OUT location on the LCD. Leaf temperatur e is di spla yed below the barometer reading on the LCD.
• If you see SOIL MOIST or LEAF WET and no number, you are seeing the moistur e and temperature readings for sensor pair #1. A two or three will appear above the readings for the second or third set of sensors.
2. If you continue to press the TEMP or HUM key , you will see the reading s for sensor pairs #2 and #3 (#3 displaye d for soil mo istur e and tempera ture on ly).
• If no sensor is installed, the reading for that sensor will be dashed out.
3. A soil moisture, temperature, or leaf wetness rea ding co nfirms communica­tion between your Leaf/Soil Station and the console.
• Disconnect the sensor(s) that were temporarily installed to tes t commu­nications.
• Go on to “Choosing a Location to Mount the Station” on page 8. If your console does not show a sensor reading, proceed to “Trouble­shooting Communication Problems
Troubleshooting Comm unication Problems
First, verify that the console/receiver is powered and is not in Setup Mode (exit Setup Mode by pressing DONE key and holding it for a moment). Then, on the Leaf/Soil Station, check that the battery is proper ly inst alled. Walk around the room with the console, standing for a few moments in various locations to see if you are picking up signals.
If you don’t see any readings, no matt er where you stand with t he console, put the transmitter in TEST mode as described below.
TEST mode
DIP switch #4 on the SIM (see illustration on page 6) is the TEST DIP-switch. Switch it to the ON position using a ball-point pen or paper clip. This puts the transmitter in Test Mode. An LED indicator light will flash each time it transmits:
• The LED will immediately flash once to show that the light itself func­tions.
• Then it will flash each time the transmitter broadcasts a signal, which should be every 10 seconds.
If the LED flashes only once and then remains dark, there is a pr ob lem with the transmitter. See “Contacting Davis Technical Support” on page 19.
Setting the DavisTalk Tran smitter ID Page 7
If the LED flashes repeatedly but your console isn’t picking up a signal anywhere in the room, it could be related to one of the following causes:
• The DIP sw itche s were not co rrectly set on t he trans mi tt er.
• Review the procedure on page 5.
• The ID was not correctly set on the console/receiver.
• Review the procedure on page 6.
• Reception is being disrupted by RF (radio frequency) interferen ce.
• There is a problem with the console/receiver.
See “Contacting Davis Technical Support” on page 19.
Note: Remember to turn DIP switch #4 OFF when you’re finished te sting wireless
transmission. If it is left ON, the blinking LED will reduce battery life significantly.
Choosing a Location to Mount the Station
Try to position your Leaf/Soil Station as follows:
• W ith the solar panel positioned for maximum exposure to the sun.
• Within transmission range of your Vantage Pr o co nsole.
• See “Range of Wir eless T ransmission” on page 8
• Within cabl e range of the sensors.
• Leaf Wetness Sensors come with 40’ (12 m) of cable standard and can be extended up to 200’ (61m) using 6-conductor 26 AWG cable.
• Soil Moisture Sen sors come with 15’ (4.6 m ) of cable standard and ca n be extended up to 1000’ (300m) using #18 gauge UF ca ble.
• Temperature Sensors come with 15’ (4.6 m) of cable st andard and can be extended up to 800’ (242m) using #24 AWG shie lded cable or up to 1200’ (260m) using #22 AWG shielded cable.
Range of Wir ele ss Transmis sion
The range of wireless tra nsmission depends on many factors. For the best receptio n, positio n th e transmit t er shelt er and yo ur conso le/receiver as close together as possible.
The maximum range is up to 400' (120 m) in the line of sight, under optimal conditions. Typical range under most conditions is 100' to 200' (30 to 60 m), but this may be reduced by walls, ceilings, trees, foliage and radio-frequency interferenc e (RF). Cordless phones, baby monitors, and ham radios ar e common examples of devices that can cause RF interference.
A metal roof or other large metal structure can interfere with the signal. Aluminum siding, a furnace with metal ducts, and your refrigerator ar e examples. Sometimes transmission between wir eless un its is obscured by something you cannot identify, or by some obstacle that you can’t work around. If necessary, consider using Wireless Repeater #76 24 or #7625 to strengthen the signal or increase the distance between the transmitter and the console/receiver .
Page 8 Wireless Leaf & Soil Moisture/ Temperature Sta-
Testing Transmission from Proposed Location
It is very important to test reception from the proposed location before per ma­nently mounting the Leaf/Soil Station.
• Place the shelter at the intended mounting site, or have someone hold it there, so you can walk around with the console/receiver for a few min­utes. Rotating the antenna may help to improve reception.
• Test w i re l e s s re ce ptio n anywhere you mi ght wa nt to us e o r m o u nt you r console/receiver now or in the future. Take your time. If you aren’t pick­ing up strong signals where you int end to place your console, bett e r to move the shelte r now th an afte r it has been moun ted . Expe ri me nt.
• If you have irregular terrain in the area, it may interfere with the signal. For example, if the transmitter is mounted downhill from the console/ recei v er, the ground may block a wi de angle of the transmitted signal.
Mounting the Leaf /Soil Station
Mounting on a Vertical Surface
1. With a 3/16" (5 mm) drill bit, drill two holes approximately 2" (50 mm) apart. Use a carpent e r’s level to ensure the holes will be level.
Flat
Washer
Lag
Screw
2. Drill two more holes 7-1/32" below the upper holes.
3. Insert the 1/4" x 1-1/2" lag screws through the flat washers, and through the holes at the top and bottom of the shelter into
Mounting Station on a Vertical Surface
the post.
4. Using an adjustable wrench or 7/16" wrench, tighten the lag screws.
Moun ti ng on a P ole
1. While holding the shelter agai nst the pole, place a U-b olt arou nd t h e po l e and through the two holes on at the
U-Bolt
top of the shelter .
2. Place a flat washer, a lock wash e r an d a hex nut on each of the bolt ends.
Flat
Washer
Lock
Washer
Hex
Nut
Mounting the Le af/ S oi l S ta tio n Pag e 9
Mounting Station on a Pole
3. Using an adjustable wrench or 7/16" wrench, tighten the nuts.
s
4. Place the second U-bolt around the pole and through the two holes at the bottom of the shelter.
5. Put a flat washer, a lock washer, and a hex nut on each bolt end, and tighten the hex nuts.
Note: If no soil temperature probe is used, the console will use a de fault temperature of
75ºF (24ºC) to compensate the soil moisture sensor readings.
6. To prevent fraying or cutting of cables, secure them so they will not whip about in the wind. Secure a cable to a metal pole by wrapping e l e ctrical ta pe around them both. Make sure cables are secure by placing clips or ties approx i m a t e l y eve ry 3 – 5' (1 – 1. 6 m).
Cable Clip
Securing Cables with Clips and Tie
Note: Do no t use met al sta ples or a stapl e gun to s ecure cables. Metal staples —
especially when installed with a staple gun — have a tendency to cut the cables.
Cable Tie
Rules for Usin g Leaf, Soil and Temperature Sensors
The following station and s ensor configurations a re sup ported by the Leaf /Soil Station:
Stati on Type in Console Configuration
LEAF/SOIL Station 2 3 3 LEAF Station 2 - 2 SOIL Station - 3 3
Number of Leaf
Wetness Sensors
Numb er of Soil
Moisture Sensors
• If your station is configured a s a LEAF/SOIL station in your Vantage Pro console, the readings for a temperatu re sensor installed in TEMP 1 or TEMP 2 will be displayed as both a leaf temp and a soil temp. A temper­ature prob e installed in TEMP 3 will only be displayed as a soil temp.
• A station configured as a LEAF station in the console will support two leaf wetness sensors and two leaf temperature pr obes.
• Leaf temperature prob es can be used as you wish to measure air, water, or soil temperature. Leaf temper ature does not affect leaf wetness read­ings.
Number of
Temperature
Probes
• A station configured as a SOIL station in the console will support three soil moisture sensors and three soil temperature probes.
Page 10 Wire less Leaf & Soil Moistu re/ Temperature St a-
• If you have i nstalled any s oil moistur e se ns ors (SOIL 1, SOIL 2, SOIL 3),
the correspondi ng temperatu re probes (TEMP 1 for SOIL 1, etc.) will be used to provide temperature co mpens ta tion for the soil moisture sensor readings.
• If you want to use a temperature sensor for something besides compen-
sation for a soil moisture senso r, then you cannot use the corresponding soil moisture sensor.
• To use one soil temperature sensor to provide compenstation for multi-
ple soil moisture sensors, install th e temperature sensor in TEMP 1.
• If no soil t emperature sensors are installed, the station will use the
default temperature of 75ºF (24ºC) to co mpensate the soil moisture r ead­ings. The soil moisture accuracy will be off by about 1 % for each 1ºF (0.5ºC) difference between the actual soil temperature and 75ºF (24ºC).
Installing Leaf Wetn ess Sensors
The leaf wetness sensor enables the station to detect the presence of surface moisture on foliage and calculate the duration of wetness. When moisture is present, the sensor detects an electrical resistance change between the gold-plated elements of the grid. This is displayed by the Vantage Pro console as a value betw een 0 (dry ) and 15 (wet ). Us ing th e WeatherLink may select your own wetness threshold; the software will then calculate leaf­wet hours.
®
software, you
See the next section, “Installing Soil Moisture & Temperature Sensors” on page 13 for information on installing temperature sensors.
Connecting Leaf Wetness Sensors
1. Run the sensor cables up through the grommets on the bottom of the station housing.
2. Insert the sensor cable modular plug into the Leaf 1 or Leaf 2 modular con­nector.
Grommets
Leaf Wetness Sensor Cables Run
Through Grommets
Connecting Leaf Wetness Sensors
Installing Leaf Wetness Sensors Page 11
Finishing the Sensor Connections to the Station
s
1. Secure sensor cables to the cabl e tie mounts located next to the grommets.
When tightening cable tie, make sure cables are on top of cable tie mount.
2. To prevent fraying or cutting of cables, secure them so they will not whip about in the wind. Secure a cable to a metal pole by wrapping electrical tape around them both. Make sure cables are secure by placing clips or t ies approximately every 3 – 5' (1 – 1.6 m).
Cable Tie
Cable Tie Mount
Securing Sensor Cables
Cable Clip
Securing Cables with Clips and Tie
Cable Tie
Note: Do no t use met al sta ples or a stapl e gun to s ecure cables. Metal staples —
especially when installed with a staple gun — have a tendency to cut the cables.
Mounting the Sensor Against a Wooden Surface
To mount the sensor against a wooden surface, secure the sensor to the surface using the #8 wood screws as shown below .
Mounting on a Wooden Surface
Page 12 Wire less Leaf & Soil Moistu re/ Temperature St a-
Mounting the Sensor on a Pipe
To mo unt th e sens o r on a pipe, stak e, or pole with out side diameter bet ween 1" and 1-1/4" (25 mm and 31 mm), secure the sensor to the pipe using the 1-1/2" U -bolts, 1/4" fl at washer s , and 1/4" hex nut s as sh own below. Use a 7/16" wrench or adjustable wr e nch to tighten the hex nu ts.
Mounting on a Pipe
Installing Soil Moisture & Temperature Sensors
The soil acts as a reservoir to store water between irrigat ion or rainfall events, so that it is available to the crop or plants as needed for healthy growth. The purpose of using sensors to measure the soil water is to give you a better understanding of h ow fast water is bein g depleted in t he dif ferent ar ea s of your field or lawn, so you can bet ter sched ule your i rriga tions a nd corr ectly ev al uate the true effectiveness of any rainfall. By monitoring the soil moisture between irrigations, you will gain a more accurate picture of this pro cess o v er t i me, and develop an irrigation scheduling pattern to meet your crop’s “need” for water. This minimizes the guesswork, resulting in water savings, lower pumping costs, and the elimination of excess leaching of nitrogen due to over irrigation.
While not absolutely necessary for operation, we recommend that a temperature pro be be installed with each soil moisture sensor. This allows the soil moisture sensor’s readings to be temperature compensated for better accuracy.
Note: WATERMARK Soil Moisture Sensor informatio n based on material supplied by
Irrometer Company, Inc.
Connecting Soil Moisture and Temperature Sensors
1. Run the sensor cables up through the grommets on the bottom of the station
housing.
2. Connect the temperature probes to the TEMP connectors.
3. Connect soil moisture probes to the SOIL connectors
Installi ng Soil Moisture & Temperature Se nsors Page 13
4. Each matched temperature probe and soil moisture pair must use the match-
r
ing connectors. If a temperature probe is not used, the soil moistur e reading can be off as much as 1% for every 1
°F (0.5°C) difference between the soil
temperature in the soil temperatur e.
Grommets
Connecting Soil Moisture and Temperature Sensors
Running Soil Moisture and T emperature Senso
Cables through Grommets
Note: If no soil temperature probe is used, the console will use a de fault temperature of
75ºF (24ºC) to compensate the soil moisture sensor readings.
Finishing the Sensor Connections to the Station
1. Secure sensor cables to the cable tie mounts located next to the grommets.
When tightening cable tie, make sure cables are on top of cable tie mount.
Securing Sensor Cables
Cable Tie
Cable Tie Mount
Page 14 Wire less Leaf & Soil Moistu re/ Temperature St a-
2. To prevent fraying or cutting of cables,
s
secure them so they will not whip about in the wind. Secure a cable to a metal pole by wrapping e l e ctrical ta pe around them both. Make sure cables are secure by placing clips or ties approx i m a t e l y eve ry 3 – 5' (1 – 1. 6 m).
Cable Clip
Securing Cables with Clips and Tie
Note: Do no t use met al sta ples or a stapl e gun to s ecure cables. Me tal staples —
especially when installed with a staple gun — have a tendency to cut the cables.
Locating Sensors
Be aware of the soil variations in your field or lawn. The lighter soils dry very quickly, heavier soils more slowly. Both conditions must be considered.
Furrow or Flood Irrigation
• Sensors are usually placed about 2/3 of the way down the run, just ahead of the tail or backup water. This is the area where water penetra­tion is usually the poorest.
Cable Tie
• In tree crops , place the sensors on the drier side o f the tree exposed to the most sun. In the Northern H e misphere, this is typically the Sout hw es t side of the tree, which is exposed to the hot afternoon sun.
Sprinkler Irrigation
• Sprinkler irrigation usually provides a more uniform distribution of water to the ground surface, but ther e can be great differ ences in pene­tration and holding capacity due to soil type variations, soil interfaces and contour. Try to place your sensors in the areas where variations occur.
• In tree crops, locate sensors at the drip line.
• In row crops, locate sensors right in the plant row.
• Be sure that sensors are not lo cated behind obstructions, such as tree limbs, which would interfere with water distribution to the sensor area.
• With center pivots, place sensors at 3 locati ons down the length of the pivot, just in front of the "st art" poi n t.
• Place sensors at "hot spots" or "good production" areas being sure to stay in active root zones.
Drip or Micro Irrigation
• Place sensors in the wetted area. Wit h drip emitters, this is usually 12” to 18” from the emitter.
• With micro-spri nkle rs or sprays , usually 24” to 36” from the micro-sprin­kler is best.
Installi ng Soil Moisture & Temperature Se nsors Page 15
Sensor Depths
Sensor depth depen ds on the rooting depth of your crop, and also depends on soil depth and texture.
Some crops need
measurement at
more than one depth
Sensor depth dependent on:
• crop rooting depth
• soil texture and depth
Sensors must be located in the effective root system of the crop
Co-locate
temperature probes
and
moisture sensors
• With shallow rooted (less than 12”) vegetable crops, one depth may be adequate.
• Deeper rooted row cro ps, small grains, vines, and trees need to be mea­sured in at least two depths.
• W it h deep well-drained soils, crops generally roo t deeper if moi sture is available.
• W it h coarse, shallow or layered soils, root systems may be limited in depth.
• Guidelines on proper depths for specific crops and conditions can be obtained from your local farm advisor.
Installation Procedure
1. Soak the soil moisture sensors overnight in water.
• Always “plant” a wet soil moisture sensor.
• If time permits, wet the soil moisture sensor for 30 minutes in the morn­ing and let dry until evening, wet for 30 minutes and let dry overnight, wet again for 30 min ut es the next morning and let dry agai n until evening. Soak over the next night and install wet. This will improve sen­sor response during the first few irrigations or waterings.
2. Make sensor ac ce ss holes to the depth re quired with a 7/8” diameter rod.
• Make a hole for the soil moist ure sensor and a separate adjacent hole for the temperature pr ob e.
• For very co ars e or gravely so i l s , an oversize hol e of 1” to 1 1/4” may be needed to prevent abrasion damage to the soil moisture sensor mem­brane. In this case, you will need to “grout in” the sensor with a slurry made from the sample soil to get a snug fit in the soil.
3. Always install sensors in the active ro ot system of the cro p with a snug fit in the soil.
Page 16 Wire less Leaf & Soil Moistu re/ Temperature St a-
CAUTION: In gravelly soils and with deeper sensors, carefully install the sensor to pre-
vent damaging the membrane.
• Lack of a snug fit is the biggest problem in obtaining good soil moisture sensor rea d­ings.
• The ideal way of making the acces s hole is to use a stepped installation tool. The stepped tool makes an oversize hole for the upper portion an d an ex act s ized ho le at t he bot tom
Cold rolled steel, round rod
1-1/4" (32 mm) approximate diameter
where the sensor is located.
• The illustration to the rig ht shows the
Overall length variable
dimensions required to make a stepped installation tool.
4. After installing the soil moisture sensor the hole needs to be carefully backfilled and tamped down. This prevents the creati on of air pockets
2-1/2" (64 mm)
which could allow water to channel down to the sensor.
• Fill the hole with water and push the sensor down into the hole so it bottoms out. A length of 1/2” Class 315 PV C tubing fits snugly over the sensor collar and can be used to push the sensor. A good snug fit in the soil is important.
• Carefully backfill the access hole with soil to eliminate any air pockets.
5. You can solvent weld the 1/2” Class 315 PVC tubing to the sensor collar for easier installation and removal.
• Use a PVC/ABS cement (IPS Weld-on #794 or equi v al e nt).
6. After you have installed the soil moisture sensors, the sensors will need one or two irrigation cycles to “break-in” and accli­mate to the soil conditions and provide bet­ter ac curacy.
Installation Procedure for Turf/Lawns
1. Cut a slight “V ” s haped trench about 5” wide at the top and about 6” deep into the turf--abo ut 6” lon g.
7/8" (22.5 mm)
Home-Made Stepped Sensor
Installation Tool
Tape
Sensor Wires
1/2" PVC Pipe
Pipe welded to sensor collar with PVC/ABS cement
2. Lift out the turf plug piece you just cut.
Installi ng Soil Moisture & Temperature Se nsors Page 17
Soil Moisture Sensor
PVC Pipe Welded to Soil Moisture
Senso r Collar
3. Press th e senso r s into th e soil at abo ut a 45 degree ang l e into th e side of the trench to set the sensors about 3”-5” below the soil surface. Make sure they are good and snug in the soil.
4. Set the plug removed from the trench and compact it back into place. It will repair itself in short order.
5. Run the wires to the Lea f /Soil Stati o n and co nnec t them as de scri bed i n “Connecting Soil Moisture and Temperature Sensors” on page 13.
6. If you withhold irrigation for several days and allow the soil to dry down a bit, you should see the soil moisture readings start to creep upwar d.
7. Usually, you will not need to water the turf until the reading is in the 25-40 area at the recommended 3”-5” dep th .
Removing the Sensors
1. When removing sen sors prior to harvest i n annual cro ps, i t’s a goo d i de a t o do this just after the last irrigation when the soil is moist.
2. Do not pull the sensor out by the wires. You may have to dig out, at least partially, any sensors more than 12” deep or any sensors in dry soil. Careful removal pr ev ents sensor and sensor membrane damage.
3. When sensors are removed for winter storage, clean the sensors, dry them, and place them in a clean, dry location.
Using Soil Moisture R eadings
Use this table as a general guide to inter pret soi l moisture r eadings. Monito ring the soil moisture readin gs, and comparing them to your field or lawn condi­tions over time, will help you develop a better understanding of how to inter­pret your soil moisture readings.
Centibar Reading Soil Condition
0-10 Saturated Soil. Occurs for a day or two after irrigation.
10-20 Soil is ad eq ua tely w et (e xc ep t coar s e sa nd s whi ch are dryi ng out at
this range)
30-60 Usual range to irrigate or water (except heavy clay soils). Irrigate at
the upper end of this range i n cool humid climates and wit h higher water-holding capacity soils.
60-100 Usual r ange to irri gate heavy cla y soils
100-200 Soil is becoming dangerously dry for maximum pro duction. Pro-
ceed wi th caution.
Page 18 Wire less Leaf & Soil Moistu re/ Temperature St a-
Troubleshooting the Sensors
If you are having problems with your station, please check all sensor cable con­nections. Cable connections account for a large portion of potential pro blems.
Use these tests to verify the correct operation of your soil moisture sensor:
1. With the sensor submerged in water, the station should show a reading
between 0 an d 5.
2. Let the sensor air dry for 30 to 48 hours. Depending on ambient tempera-
ture, humidity, and air movement, the reading should be 150 or over.
3. Put the sensor back in the water. The reading should run right back to 0 to 5
within 1 to 2 minutes.
4. If the sensor does not pass these tests, please contact Davis Technical Sup-
port for help in resolving the problem.
Extending Sensor Cable Lengt h
Both the soil moisture sensors and the temperatur e probes come with 15’ (4.6 m) direct burial cables. The lea f w etness sensor comes w i th a 40’ (12m) cable.
• Leaf Wetness Sensor cables can be extended up to 200’ (61m) using 6­conductor 26 AWG cable.
• Soil Mo ist ure Sen sor cabl e s can be ext ended u p to 1000 ’ (300 m) u sing # 18 gauge waterproof cable. UF insulation is recommended.
• Temperature Se ns ors can be exte nde d up to 800’ (242m) using #24 AWG shielded cable or up to 1200’ (260m) using #22 AWG shielded cable.
• The additional wire must be fully waterproof.
• We recommend u s i ng a 3M Sco tchpa k or Dur a s e al heat sh r i nk spl i c e connector when extending the sensor cables.
Note: Avoid lon g wi re ru ns nea r power cable s. The tran s ien t curren ts ca n affect the
small current used to read the sensors.
Contacting Davis Technical Support
If you have questions about your Leaf/Soil Station, or encounter problems installing or operating the station, please contact Davis Technical Support.
Note: Please do not retu r n items to the fac tor y for repa ir w ith ou t prio r aut ho riz at io n.
(510) 732-7814 – Monday – Fri day, 7:00 a.m. – 5:30 p.m. Pacific Time. support@davisnet.com – E-mail to Technical Support. (510) 732-9229 – For callers outside the USA or Canada. (510) 670-0589 – Fax . www.davisnet.com – Copies of User Manuals are available on the “Support”
page. Watch for FAQs and other updates. Subscribe to the e-newsletter. info@davisnet.com – General e-mail.
Troubles hooting the Sensors Page 19
Specifications
Let Wetness rang e: 0 to 15 Soil Moisture range: 0 to 200 centibars Temperature range (Station & Temp Probe): –40 to 150° Fahrenhei t
(–40 to 65° Ce ls iu s )
Temperature range (Soil Moisture Sensor): 32 to 105° Fahrenheit
(0 to 40° Cels iu s ) Prima ry pow er input: Solar power – Da v is sola r cha rger Secondary (backup) power: CR-123A 3-volt lithium battery Wireless transmission frequency: 916.5 MHz
(868.35 MHz for over seas version – Product # includes “ O V”) Transmitter ID codes: 8 user-selectable License: low power (less than 1 mW), no license required
FCC Part 1 5 Cla ss B Regi strati on Warning
This equipment has been tested and found to comply with the limits for a class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against ha rmful inter­ference in a residential insta llat ion. This eq ui pment genera tes, uses and can radia te radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation.
If this equipment does cause harmful interference to radio or televi sion reception, which can be determined by turning the equipment off and on, the user is encourage d to try to correct the interference by one or more of the following measures:
Reorient or relocate the receiving antenna.
Increase the sepa rati on between the equipment and receiver .
Connect the equipment into an outlet on a circuit different fr om that to which the receiver is connected.
Consult the dealer or an experienced radio/TV techn ician for help. Changes or modifications not expressly approved in writing by Davis Instruments may void the user's authority to operate this equipment.
Product Number: 6343 Davis Instruments Part Number: 7395.167 Wireless Leaf & Soil Moisture/ Temperature Station Rev A Manual (7 May 2002)
This product complies with the essential protection requirements of the EC EMC Directive 89/336/EC. The term "IC:" before the radio certificaiton number only signifies that Industry of Canada technical
specifications were met. Copyright © 2002 Davis Instruments Corp. All rights reserved.
The WATERMARK soil moisture sensor is a product of Irrometer Company, Inc.
3465 Diablo Avenue, Hayward, CA 94545-2778
510-732-9229 • Fax: 510-732-9188
E-mail: info@davisnet.com • www.davisnet.com
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