Measure Soil Moisture - Revision history

Admin at 01:33, 21 August 2021

2021-08-21T01:33:38Z

Admin at 23:45, 20 August 2021

2021-08-20T23:45:55Z

Admin at 23:02, 20 August 2021

2021-08-20T23:02:13Z

Admin at 07:48, 20 August 2021

2021-08-20T07:48:17Z

Admin at 07:32, 20 August 2021

2021-08-20T07:32:34Z

Admin at 01:43, 18 August 2014

2014-08-18T01:43:57Z

Admin at 00:49, 24 July 2014

2014-07-24T00:49:50Z

Admin at 22:49, 23 July 2014

2014-07-23T22:49:25Z

Admin: Admin moved page Soil Moisture Sensors to Measure Soil Moisture without leaving a redirect

2012-08-10T05:20:08Z

Admin moved page Soil Moisture Sensors to Measure Soil Moisture without leaving a redirect

Admin: Created page with "There are many different ways to check the soil moisture in your garden. This is a summary of the different instruments and techniques available measuring soil moisture. Als..."

2012-07-02T02:40:07Z

Created page with "There are many different ways to check the soil moisture in your garden. This is a summary of the different instruments and techniques available measuring soil moisture. Als..."

New page

There are many different ways to check the soil moisture in your garden. This is a summary of the different instruments and techniques available measuring soil moisture. Also included are links to resources for making your own sensors.

=Manual Methods=

== Plant Appearance==
When you see noticeable signs plant distress like wilting, it means the plant has run out of water. This is not good for the plant and is a poor way to determine when to water.

==Fingers==
Just feel the soil. It can be hard to judge other than the surface moisture unless you dig a hole.

==Wood Probes==
If the soil is soft you can use a thin wood stick such as a skewer to probe the soil. Insert the stick and when you can pull it out you can observe or feel it to determine how moist the soil is.
<amazon id=B001IWOSCU>[%buy% %mediumimage%] [%buy% 10-Inch Bamboo Grilling Kabob Skewers]</amazon>

==Notched stick==
[[File:Inside_urban_green_soil_probe.jpg|150px]] To use these, you push into the soil, rotate, and pull out. You can then access the soil moisture by observing and feeling the soil samples retrieved in the notches. See this article for more details [http://www.insideurbangreen.org/2008/08/a-better-way-to-check-soil-moisture.html A Better Way To Check Soil Moisture]

==Soil cores==
<amazon id=B004NERJ5S>[%buy% %mediumimage%] [%buy% Tubular Soil Sampler - From Amazon]</amazon> These come in various lengths up to several feet long

==Bottom Wick==
For containers, [[Al Tapla]] suggests putting an adsorbent wick hanging down from the bottom of the pot. You can just feel it where it exits the pot to determine if the soil is still moist. See Also: [[Container wicks]]

==Weight==
For containers, if you are familiar with the plant, you can just lift or weigh it to get a feel for how much water is in the soil.

=Soil Meters=
There are many different types of meters to measure soil moisture. They range in cost from a few dollars up to a few thousand dollars.
The low cost meters are almost all conductivity meters. The most expensive ones are radar based.
==Soil Electrolyte Meters==
These meters have a probe with two dissimilar metals separated by an insulator. When the probe is inserted into the ground the two disimular metals and the moist soil form a simple battery and the output of this battery is displayed on a meter to indicate soil moisture. The more moist the soil, the higher the battery output and the higher the reading on the meter. The main disadvantage of these meters is erroneous readings when the soil contains too high a concentration of salts or minerals or when the probe metals oxidize or otherwise no longer make good contact with the soil. Sometimes cleaning the probe with steel wool can help, but check manufacturer instructions frist. The advantage of these meters is that they require no battery, and are low cost and very simple to use. These meters are often combined with probes for PH.

Examples of these meters are:
* {{amazon|B002B80FU4|Indoor/Outdoor Moisture Sensor Meter]}}
* {{amazon|B001A5OR5I|Luster Leaf 1820 Rapitest Soil Moisture Meter}}
* {{amazon|B000HHLJQA|Luster Leaf 1880 Rapitest Electronic 4-Way Analyzer}}
* {{amazon|B00636VPNG|3-in-1 Moisture, pH & Light Garden Soil Probe Meter}}

==Soil Resistance (or Conductivity) Meters==
These meters typically have a battery and work by the electrolyte effect described above or measure the resistance of the soil by sending a small current through the soil. Moist soil is more conductive (lower resistance) and so will conduct more current. The results are displayed on an analog or digital meter. The disadvantages of this meter type are: batteries required, erroneous readings when the soil contains too high a concentration of salts or minerals or when the probe metals oxidize or otherwise no longer make good contact with the soil. Sometimes cleaning the probe with steel wool can help, but check manufacturer instructions first. The advantages of these meters are: usually low cost and very simple to use.

Examples of these meters are:
* {{amazon|B0032WFD4G|Luster Leaf 1825 Rapitest Digital Moisture Meter}}
* {{amazon|B0017RXJUS|Hydrofarm HGTL Thirsty Light Original Digital Indoor Plant Moisture Sensor}} This sensor flashes a light when the soil is too dry
* {{amazon|B002OEJ682|Singing Blue Jay - Plant Pal Soil Moisture Meter}} Bird sings when soil is dry

===DIY Do It Yourself Sensors===
* [http://home.roadrunner.com/~randylinscott/nov20.htm Randy Linscott Circuit] A schematic for a 741 op amp based sensor
* [http://www.waset.org/journals/waset/v35/v35-57.pdf A High Accuracy Measurement Circuit for Soil Moisture Detection]
* [http://www.botanicalls.com/ www.botanicals.com] Plans and kits for soil sensors connected to the internet.
* [http://www.faludi.com/2006/11/02/moisture-sensor-circuit/ Moisture Sensor Circuit] Blog post with schematic for a simple sensor and numerous reader comments.
* [http://store.qkits.com/moreinfo.cfm/FK908 Soil Moisture Indicator Kit] Kit for soil moisture sensor
* [http://www.discovercircuits.com/S/s-water.htm Sensors, Detectors: Water, Moisture Sensors] circuits for various moisture sensors
* [http://www.cheapvegetablegardener.com/2009/11/how-to-make-cheap-soil-moisture-sensor-2.html HOW TO MAKE A CHEAP SOIL MOISTURE SENSOR â HEAVY DUTY VERSION] Detailed instructions for making gypsum block sensors. Reader comments discuss alternative methods. including capacitance sensors and the [[Business:Vegetronix]] sensor.
* [http://www.circuitdiagram.org/plant-soil-moisture-tester-circuit.html Plant Soil Moisture Tester Circuit] Very simple circuit or measuring moisture
* [http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1255471714/all How to: soil moisture measurement] Discussion on the Arduino Forum on designing and making sensors
* [http://electroschematics.com/761/soil-moisture-tester/ SOIL MOISTURE TESTER] Article about building a soil moisture sensor, includes schematics.

==Soil Capacitance Meters==
The [[wikipedia:Capacitance]] of soil depends on how moist it is. If two parallel conducting probes are placed in the soil, then they form a [[wikipedia:capacitor]] with the soil as the [[wikipedia:Dielectric]]. As the moisture of the soil changes, the relative [[wikipedia:Permittivity]] of the soil changes and as a result the capacitance between the probes changes. The capacitance values are very small on the order of a few pico farads and so require a little effort to measure. One common method is to create an oscillator using the soil capacitance to set the frequency. As the to soil moisture changes, the capacitance changes and the oscillator frequency shifts. This frequency shift is measured and displayed to show the soil moisture.

These meters have the advantage of being reasonably independent of the soil mineralization, and the metal in the soil probes can be insulated and so are less prone to oxidize or otherwise deteriorate from being in direct contact with the soil. Since the measurement is affected by the soil both to the sides and between the probes, this method is more of an overall indication of the soil moisture rather than just the soil directly between the tips of the probes as in the case of the soil conductivity meters.

These meters were once very expensive, but prices have dropped with the advent of micro processors.

===Consumer Products===
* {{amazon|B003Z4JV8K|Black & Decker PCS10 PlantSmart Digital Plant Care Sensor}} uses technology licensed from [[Business:Vegetronix|Vegetronix]]
* {{amazon|B001RLVVR2|Fertile Earth WaterStik Plant Moisture Sensor}} uses technology licensed from [[Business:Vegetronix|Vegetronix]]
===Commercial Systems===
* [http://www.aquapro-sensors.com/ AquaPro Soil Moisture Sensors] uses left-in-the-ground access tubes. A capacitance probe is inserted in the access tube and can take readings at various soil depths.
===System Components===
* [[Business:Vegetronix|Vegetronix]] makes several different models that are relatively low cost and easy to inferface to micro processors and other systems.
* [[Business:Decagon Devices]] makes a range of different professional grade soil sensors
===DIY Do It Yourself Sensors===
It is not difficult to fabricate you own soil capacitance sensors.
* [http://www.dietmar-weisser.de/elektronikprojekte1/analogtechnik/feuchtesensor Analog soil moisture sensor] Article includes PCB layout, Schematic, and Source code. In German - use Google Translate
* [http://www.dietmar-weisser.de/elektronikprojekte1/analogtechnik/78-pflanzen-giessindikator plant GieÃindikator] Article includes PCB layout, Schematic, and Source code. In German - use Google Translate
* [http://gardenbot.org/forum/viewtopic.php?f=2&t=7 soil moisture sensor comparison] An Adafruit forum discussion on building capacitance soil moisture sensors
* [http://www.deepdarc.com/?q=moisture Soil Moisture Sensor] Blog posts about building a capacitance soil moisture sensor that include schematics and pcb layouts
* [http://www.actahort.org/books/171/171_6.htm A CAPACITANCE SOIL MOISTURE METER] A research paper describing a sensor made from two lengths of wire. Only the abstract is available free -- check your library.
* [http://hulk.bu.edu/pubs/papers/2007/TR-05-02-2007.doc WiGreen Soil Moisture Sensing System] Student project from Boston University. A description of a student designed and built network of soil sensors and a central computer system to collect the data.
* [http://www.sowacs.com/sensors/capacitance.html CAPACITANCE SENSORS (FDR)] describes how capacitive probes work, and has links to manufacturers and other information -- a number of dead links but still a good resource
* [http://dei-s1.dei.uminho.pt/pessoas/higino/pampus/AV_ISIE00.pdf On-chip integrated silicon bulk-micromachined soil moisture sensor with electronics and bus interface] Research paper describes building at testing a low cost sensor based on capacitive and heat-pulse methods.
* [http://www98.griffith.edu.au/dspace/bitstream/10072/9072/1/21909.pdf Contributions to the Measured Capacitance by the Dielectric Properties of Water in Insulated Electrode Soil Moisture Sensors] Research paper that compares the theory to experimental results for capacitive soil sensors.
* [http://ieeexplore.ieee.org/Xplore/login.jsp?reload=true&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F10646%2F33608%2F01597624.pdf%3Farnumber%3D1597624&authDecision=-203 Wireless soil moisture sensor based on fringing capacitance] Only the abstract is free online. Check you Library.
* [http://www.crops.org/publications/sssaj/pdfs/68/2/430 Calibration of Capacitance Probe Sensors using Electric Circuit Theory] Research paper comparing theory to experimental results
* [http://vfd.ifas.ufl.edu/gainesville/irrigation/capacitance_probe.shtml Volumetric Sensors for Soil Moisture: Capacitance Probe] University of Florida describes advantages and disadvantages of capacitance and other probes.
* [http://www.agri.gov.il/en/people/788.aspx Arie Nadler, Ph.D.] Personal page for soil researcher, includes a schematic for a capacitive soil probe

==Frequency domain reflectometry (FDR)==
FDR systems send an oscillating signal into a buried [[Wikipedia:Transmission Line|transmission line]] and then measure the frequency of the signal that is reflected back. The amount of moisture in the soil changes the [[Wikipedia:Dielectric constant|dielectric constant]] of the soil and as a result the frequency of the reflected signal. So the difference of the sent and received signals changes depending on the soil moisture.

==Time Domain Reflectometry (TDR)==
Measures the speed of a radio wave through [[Wikipedia:Transmission Line|transmission line]] buried in the soil. The amount of moisture in the soil changes [[Wikipedia:Dielectric constant|Dielectric constant]] of the soil and as a result the speed of the signal. TDR sensors send a electromagnetic pulse into the buried transmission line and then measure how long it takes to see the pulse reflected back from the end of the buried transmission line.

==Time Domain Transmission (TDT)==
Measures the one-way time for an electromagnetic pulse to travel over the length of a [[Wikipedia:Transmission Line|Transmission Line]]. This is similar to the [[Wikipedia:Time-domain reflectometer|TDR]] technique, but rather than measuring the reflections of the pulse, it measures the one-way transit time of the pulse over the length of the transmission line by using equipment at both ends of the transmission line.
Since soil moisture changes the speed of the signal, the amount of water in the soil can be calculated from the transit time of the signal. Typically these sensors are permanently installed in the soil.
* [http://www.streatsahead.com/Pages/Aquaflex%20Menu.html AQUAFLEX soil moisture meters] The Aquaflex sensor loops the transmission line so that physically all of the electronics are at one end of the sensor.

===Coaxial Impedance Dielectric Reflectometry===
Similar to FDR and TDR sensors described above. The sensor sends an oscillating signal into the soil and measures the signal reflected from the soil itself to determine the soil moisture.
* [http://www.stevenswater.com/soil_moisture_sensors/index.aspx Hydra Probe Soil Moisture Sensor]

==Gravimetric==
Take some soil weigh it, put it in the oven, heat it to drive out all the water, weigh it, the difference is the amount of water that was in the soil. Accurate, but not practical for frequent measurements.

==Soil Water Tension==
[[File:Tensiometer.png|left|100px|alt=Tensiometer diagram|1. Porus cup, usually ceramic 2. tube, length will vary depending on depth being measured 3. Top Seal 4. Pressure sensor/vacuum gauge]]

These sensors (Tensiometers) measure how hard it is to extract water from the soil, i.e. they measure soil water tension. This is the same water tension that plants must overcome to extract water from the soil.
Typically these sensors are a sealed water filled pipe with a ceramic cup at the soil end, and a vacuum gauge at the top. When the soil is dry, water travels through the ceramic cup into the soil and creates a vacuum at the top of the pipe which can be measured with the vacuum gauge. When water is added to the soil, water travels back from the soil through the ceramic cup into the pipe decreasing the vacuum at the top of the pipe. It is possible to make you own Tensionmeters although I have not seen anyone do it recently.
* [http://www.dynamax.com/tensiometers.htm Dynamax Tensiometers]
* [http://www.irrometer.com/sensors.html IRROMETER Tensiometers]

==Neutron Thermalisation==
Measures how much water in the soil slows down neutrons. Expensive.
* [http://www.troxlerlabs.com/products/4301.php Troxler MODEL 4300 SOIL MOISTURE GAUGE]
* [http://instrotek.com/material-testing/field-products/503dr-hydroprobe/ InstroTek 503DR Hydroprobe] Company used to be called CPN International, Inc and research papers often refer to CPN probes.

==Thermal Dissipation==
Measures how heat dissipates in the soil which changes with soil moisture.
Depends on a dry soil heating up faster than a moist soil. The sensor is a porous block with an embedded heater and temperature sensor. To make a measurement, the temperature is measured, the header turned on for a fixed time period, then the temperature is measured again. The difference between the beginning and ending temperatures is a function of how much moisture is in the soil.

Example: AquaSensor

==Soil Thermocouple Psychrometers==
This method requires putting a sample in sealed chamber and indirectly measuring water that evaporates from the soil with a thermocouple.
* [http://dspace.udel.edu:8080/dspace/bitstream/handle/19716/2828/Chapter%203.%20Thermocouple%20Psychrometer.pdf?sequence=6 Thermocouple Psychrometry] Chapter in the book: [http://dspace.udel.edu:8080/dspace/handle/19716/2828 Measuring the water status of plants and soils] describing the technique.

=References=
* [http://www.irrigationnz.co.nz/assets/Uploads/2.4.1-Soil-Moisture-parts-1-and-2.pdf Soil Moisture] short handbook for farmers on measuring soil moisture

@@ Line 46: / Line 46: @@
 ===DIY Do It Yourself Sensors===
 * [http://www.faludi.com/2006/11/02/moisture-sensor-circuit/ Moisture Sensor Circuit] Blog post with schematic for a simple sensor and numerous reader comments.
-* [http://store.qkits.com/moreinfo.cfm/FK908 Soil Moisture Indicator Kit] Kit for soil moisture sensor
+* [https://store.qkits.com/catalogsearch/result/?q=soil+moisture Qkit Elecronics] Kits for soil moisture sensor
 * [http://www.discovercircuits.com/S/s-water.htm Sensors, Detectors: Water, Moisture Sensors] circuits for various moisture sensors
-* [http://www.cheapvegetablegardener.com/2009/11/how-to-make-cheap-soil-moisture-sensor-2.html HOW TO MAKE A CHEAP SOIL MOISTURE SENSOR â HEAVY DUTY VERSION] Detailed instructions for making gypsum block sensors.  Reader comments discuss alternative methods. including capacitance sensors and the [[Business:Vegetronix]] sensor.
+* [http://www.cheapvegetablegardener.com/how-to-make-cheap-soil-moisture-sensor-2/ HOW TO MAKE A CHEAP SOIL MOISTURE SENSOR â HEAVY DUTY VERSION] Detailed instructions for making gypsum block sensors.  Reader comments discuss alternative methods. including capacitance sensors and the [https://www.vegetronix.com Vegetronix] sensor.
 * [http://www.circuitdiagram.org/plant-soil-moisture-tester-circuit.html Plant Soil Moisture Tester Circuit] Very simple circuit or measuring moisture
 * [http://electroschematics.com/761/soil-moisture-tester/ SOIL MOISTURE TESTER] Article about building a soil moisture sensor, includes schematics.
@@ Line 65: / Line 61: @@
 ===Consumer Products===
 * {{amazonlinkt|link_text=Ecowitt remote sensor with meter -- sensor available separately for use in larger Ecowitt systems |az=<a target="_blank"  href="https://www.amazon.com/gp/product/B07CJYTSH1/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B07CJYTSH1&linkCode=as2&tag=gardeinfo01-20&linkId=057533670a8ec2526b545b32f41517bc"><img border="0" src="//ws-na.amazon-adsystem.com/widgets/q?_encoding=UTF8&MarketPlace=US&ASIN=B07CJYTSH1&ServiceVersion=20070822&ID=AsinImage&WS=1&Format=_SL250_&tag=gardeinfo01-20" ></a>}}
 ===System Components===
-* [https://www.vegetronix.com Vegetronix]] makes several different models that are relatively low cost and easy to inferface to micro processors and other systems.
+* [https://www.vegetronix.com Vegetronix] makes several different models that are relatively low cost and easy to inferface to micro processors and other systems.
 * [http://www.decagon.com/en/education/application/plant-ecology/ Decagon Devices] makes a range of different professional grade soil sensors
 ===DIY Do It Yourself Sensors===
 It is not difficult to fabricate you own soil capacitance sensors.
 * [http://www.actahort.org/books/171/171_6.htm A CAPACITANCE SOIL MOISTURE METER] A research paper describing a sensor made from two lengths of wire.  Only the abstract is available free -- check your library.
 * [http://hulk.bu.edu/pubs/papers/2007/TR-05-02-2007.doc WiGreen Soil Moisture Sensing System] Student project from Boston University. A description of a student designed and built network of soil sensors and a central computer system to collect the data.
 * [http://dei-s1.dei.uminho.pt/pessoas/higino/pampus/AV_ISIE00.pdf On-chip integrated silicon bulk-micromachined soil moisture sensor with electronics and bus interface] Research paper describes building at testing a low cost sensor based on capacitive and heat-pulse methods.
 * [http://www98.griffith.edu.au/dspace/bitstream/10072/9072/1/21909.pdf Contributions to the Measured Capacitance by the Dielectric Properties of Water in Insulated Electrode Soil Moisture Sensors] Research paper that compares the theory to experimental results for capacitive soil sensors.
-* [http://ieeexplore.ieee.org/Xplore/login.jsp?reload=true&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F10646%2F33608%2F01597624.pdf%3Farnumber%3D1597624&authDecision=-203 Wireless soil moisture sensor based on fringing capacitance] Only the abstract is free online.  Check you Library.
+* [https://www.researchgate.net/publication/4224566_Wireless_Soil_Moisture_Sensor_Based_on_Fringing_Capacitance Wireless soil moisture sensor based on fringing capacitance] Only the abstract is free online.  Check you Library.
 * [http://www.crops.org/publications/sssaj/pdfs/68/2/430 Calibration of Capacitance Probe Sensors using Electric Circuit Theory] Research paper comparing theory to experimental results
-* [http://vfd.ifas.ufl.edu/gainesville/irrigation/capacitance_probe.shtml Volumetric Sensors for Soil Moisture: Capacitance Probe] University of Florida describes advantages and disadvantages of capacitance and other probes.
+* [https://www.fertinnowa.com/technologies/capacitance-probes-measuring-soil-moisture/ Capacitance probes for measuring soil moisture] Fertinnowa articles on capacitance probes
 * [http://www.agri.gov.il/en/people/788.aspx Arie Nadler, Ph.D.] Personal page for soil researcher, includes a schematic for a capacitive soil probe
 ==Chemical Color Change==
-[https://sustee.jp/en/ Sustee] has developed a soil moisture sensor that uses a chemical color change to indicate moisture level: white for dry and blue for wet. The sensors come in varying lengths.  According to the Sustee FAQ, after six months of use, they may need a core refill replacement.
+Some materials will change color depending on how moist they are.  Some materials may have a limited useful lifetime.
-* {{amazonlinkt|link_text=Sustee Aquameter, Plant Moisture Sensor, Set of 2 (Green, Large)|az=<a target="_blank"  href="https://www.amazon.com/gp/product/B076CGZGJ8/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B076CGZGJ8&linkCode=as2&tag=gardeinfo01-20&linkId=ebe5b6e2ebddb1b3d45da031ac506ed2"><img border="0" src="//ws-na.amazon-adsystem.com/widgets/q?_encoding=UTF8&MarketPlace=US&ASIN=B076CGZGJ8&ServiceVersion=20070822&ID=AsinImage&WS=1&Format=_SL250_&tag=gardeinfo01-20" ></a>}}
+Sensors that use this effect:
@@ Line 104: / Line 96: @@
 ===Coaxial Impedance Dielectric Reflectometry===
 Similar to FDR and TDR sensors described above.  The sensor sends an oscillating signal into the soil and measures the signal reflected from the soil itself to determine the soil moisture.
-* [http://www.stevenswater.com/soil_moisture_sensors/index.aspx Hydra Probe Soil Moisture Sensor]
+* [https://stevenswater.com/applications/soil-monitoring/ Hydra Probe Soil Moisture Sensor]
 ==Gravimetric==
@@ Line 114: / Line 106: @@
 These sensors (Tensiometers) measure how hard it is to extract water from the soil, i.e. they measure soil water tension.  This is the same water tension that plants must overcome to extract water from the soil.
 Typically these sensors are a sealed water filled pipe with a ceramic cup at the soil end, and a vacuum gauge at the top. When the soil is dry, water travels through the ceramic cup into the soil and creates a vacuum at the top of the pipe which can be measured with the vacuum gauge.  When water is added to the soil, water travels back from the soil through the ceramic cup into the pipe decreasing the vacuum at the top of the pipe. It is possible to make you own Tensionmeters although I have not seen anyone do it recently.
-* [http://www.dynamax.com/tensiometers.htm Dynamax Tensiometers]
+* [https://dynamax.com/products/soil-moisture/eq3-equitensiometer Dynamax Tensiometers]
 * [http://www.irrometer.com/sensors.html IRROMETER Tensiometers]
@@ Line 120: / Line 112: @@
 ==Neutron Thermalisation==
 Measures how much water in the soil slows down neutrons.  Expensive.
-* [http://www.troxlerlabs.com/products/4301.php Troxler MODEL 4300 SOIL MOISTURE GAUGE]
+* [https://www.troxlerlabs.com/products/details?prodid=44 Troxler SOIL MOISTURE GAUGE]
-* [http://instrotek.com/material-testing/field-products/503dr-hydroprobe/ InstroTek  503DR Hydroprobe] Company used to be called CPN International, Inc and research papers often refer to CPN probes.
+* [https://www.instrotek.com/products/503-elite-hydroprobe InstroTek Hydroprobe] Company used to be called CPN International, Inc and research papers often refer to CPN probes.
 ==Thermal Dissipation==
@@ Line 131: / Line 123: @@
 ==Soil Thermocouple Psychrometers==
 This method requires putting a sample in sealed chamber and indirectly measuring water that evaporates from the soil with a thermocouple.
-* [http://dspace.udel.edu:8080/dspace/bitstream/handle/19716/2828/Chapter%203.%20Thermocouple%20Psychrometer.pdf?sequence=6 Thermocouple Psychrometry] Chapter in the book: [http://dspace.udel.edu:8080/dspace/handle/19716/2828 Measuring the water status of plants and soils] describing the technique.
+* [https://udspace.udel.edu/bitstream/handle/19716/2828/Chapter%203.%20Thermocouple%20Psychrometer.pdf?sequence=6&isAllowed=y Thermocouple Psychrometry] Chapter in the book: [https://udspace.udel.edu/handle/19716/2828 Measuring the water status of plants and soils] describing the technique.
 =References=

@@ Line 34: / Line 34: @@
 Examples of these meters are:
-* {{amazon|B002B80FU4|Indoor/Outdoor Moisture Sensor Meter]}}
+* {{amazonlinkt|link_text=Indoor/Outdoor Moisture Sensor Meter|az=<a target="_blank"  href="https://www.amazon.com/gp/product/B002B80FU4/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B002B80FU4&linkCode=as2&tag=gardeinfo01-20&linkId=8048a4dc73d0113457ca2edb803ddfe4"><img border="0" src="//ws-na.amazon-adsystem.com/widgets/q?_encoding=UTF8&MarketPlace=US&ASIN=B002B80FU4&ServiceVersion=20070822&ID=AsinImage&WS=1&Format=_SL250_&tag=gardeinfo01-20" ></a>}}
-* {{amazon|B001A5OR5I|Luster Leaf 1820 Rapitest Soil Moisture Meter}}
+* {{amazonlinkt|link_text=SONKIR Soil pH Meter, MS02 3-in-1 Soil Moisture/Light/pH Tester|az=<a target="_blank"  href="https://www.amazon.com/gp/product/B07BR52P26/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B07BR52P26&linkCode=as2&tag=gardeinfo01-20&linkId=49b7ffb3b1e3f50398fa5443a31ffae6"><img border="0" src="//ws-na.amazon-adsystem.com/widgets/q?_encoding=UTF8&MarketPlace=US&ASIN=B07BR52P26&ServiceVersion=20070822&ID=AsinImage&WS=1&Format=_SL250_&tag=gardeinfo01-20" ></a>}}
@@ Line 44: / Line 42: @@
 Examples of these meters are:
-* {{amazon|B0032WFD4G|Luster Leaf 1825 Rapitest Digital Moisture Meter}}
+* {{amazonlinkt|link_text=Luster Leaf Rapitest Digital Moisture Meter|az=<a target="_blank"  href="https://www.amazon.com/gp/product/B0032WFD4G/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B0032WFD4G&linkCode=as2&tag=gardeinfo01-20&linkId=08a7ed2bf536f21fd6a46605baad90ee"><img border="0" src="//ws-na.amazon-adsystem.com/widgets/q?_encoding=UTF8&MarketPlace=US&ASIN=B0032WFD4G&ServiceVersion=20070822&ID=AsinImage&WS=1&Format=_SL250_&tag=gardeinfo01-20" ></a>}}
-* {{amazon|B0017RXJUS|Hydrofarm HGTL Thirsty Light Original Digital Indoor Plant Moisture Sensor}} This sensor flashes a light when the soil is too dry
+* {{amazonlinkt|link_text=REOTEMP Garden and Compost Moisture Meter (15 Inch Stem). There is also a 36" version|az=<a target="_blank"  href="https://www.amazon.com/gp/product/B07DM4LS1D/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B07DM4LS1D&linkCode=as2&tag=gardeinfo01-20&linkId=5fac2a93179d9031278d15a2b52908e3"><img border="0" src="//ws-na.amazon-adsystem.com/widgets/q?_encoding=UTF8&MarketPlace=US&ASIN=B07DM4LS1D&ServiceVersion=20070822&ID=AsinImage&WS=1&Format=_SL250_&tag=gardeinfo01-20" ></a>}}
 ===DIY Do It Yourself Sensors===
@@ Line 61: / Line 58: @@
 ==Soil Capacitance Meters==
-The [[wikipedia:Capacitance|capacitance]] of soil depends on how moist it is.  If two parallel conducting probes are placed in the soil, then they form a [[wikipedia:capacitor]] with the soil as the [[wikipedia:Dielectric]].  As the moisture of the soil changes, the relative [[wikipedia:Permittivity]] of the soil changes and as a result the capacitance between the probes changes.  The capacitance values are very small on the order of a few pico farads and so require a little effort to measure.  One common method is to create an oscillator using the soil capacitance to set the frequency.  As the to soil moisture changes, the capacitance changes and the oscillator frequency shifts.  This frequency shift is measured and displayed to show the soil moisture.
+The [[wikipedia:Capacitance|capacitance]] of soil depends on how moist it is.  If two parallel conducting probes are placed in the soil, then they form a [[wikipedia:capacitor|capacitor]] with the soil as the [[wikipedia:Dielectric|dielectric]].  As the moisture of the soil changes, the relative [[wikipedia:Permittivity|permittivity]] of the soil changes and as a result the capacitance between the probes changes.  The capacitance values are very small on the order of a few pico farads and so require a little effort to measure.  One common method is to create an oscillator using the soil capacitance to set the frequency.  As the to soil moisture changes, the capacitance changes and the oscillator frequency shifts.  This frequency shift is measured and displayed to show the soil moisture.
 These meters have the advantage of being reasonably independent of the soil mineralization, and the metal in the soil probes can be insulated and so are less prone to oxidize or otherwise deteriorate from being in direct contact with the soil.  Since the measurement is affected by the soil both to the sides and between the probes, this method is more of an overall indication of the soil moisture rather than just the soil directly between the tips of the probes as in the case of the soil conductivity meters.
@@ Line 68: / Line 65: @@
 ===Consumer Products===
-* {{amazon|B00FOM2Y6W|Parrot Flower Power - Wireless Indoor/Outdoor Bluetooth Smart Plant Sensor }} seems to be the successor to the Black and Decker PCS10 PlantSmart Digital Plant Care Sensor,
 * [http://www.aquapro-sensors.com/ AquaPro Soil Moisture Sensors] uses left-in-the-ground access tubes.  A capacitance probe is inserted in the access tube and can take readings at various soil depths.
 ===System Components===
@@ Line 117: / Line 111: @@
 * [http://www.dynamax.com/tensiometers.htm Dynamax Tensiometers]
 * [http://www.irrometer.com/sensors.html IRROMETER Tensiometers]
 ==Neutron Thermalisation==

@@ Line 10: / Line 10: @@
 ==Wood Probes==
-If the soil is soft you can use a thin wood stick such as a skewer to probe the soil.  Insert the stick and when you can pull it out you can observe or feel it to determine how moist the soil is.
+If the soil is soft you can use a thin wood stick such as a skewer to probe the soil.  Insert the stick and when you can pull it out you can observe or feel it to determine how moist the soil is.<br>
-<amazon id=B001IWOSCU>[%buy% %mediumimage%] [%buy% 10-Inch Bamboo Grilling Kabob Skewers]</amazon>
+{{amazonlinkt|link_text=Amazon - 12-Inch Bamboo Skewers|az=<a target="_blank"  href="https://www.amazon.com/gp/product/B07MY7W5LJ/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B07MY7W5LJ&linkCode=as2&tag=gardeinfo01-20&linkId=57af4837664fd56721802afedb939893"><img border="0" src="//ws-na.amazon-adsystem.com/widgets/q?_encoding=UTF8&MarketPlace=US&ASIN=B07MY7W5LJ&ServiceVersion=20070822&ID=AsinImage&WS=1&Format=_SL250_&tag=gardeinfo01-20" ></a>}}
 ==Notched stick==
@@ Line 17: / Line 17: @@
 ==Soil cores==
-<amazon id=B004NERJ5S>[%buy% %mediumimage%] [%buy% Tubular Soil Sampler - From Amazon]</amazon>  These come in various lengths up to several feet long
+A hollow tube you push into the soil to extract a column of soil for examination.
 ==Bottom Wick==

@@ Line 66: / Line 66: @@
 ===Consumer Products===
 * {{amazon|B003Z4JV8K|The now discontinued Black and Decker PCS10 PlantSmart Digital Plant Care Sensor}} used technology licensed from [[Business:Vegetronix|Vegetronix]]
 * {{amazon|B001RLVVR2|Fertile Earth WaterStik Plant Moisture Sensor}} uses technology licensed from [[Business:Vegetronix|Vegetronix]]

@@ Line 14: / Line 14: @@
 ==Notched stick==
-[[File:Inside_urban_green_soil_probe.jpg|150px]] To use these, you push into the soil, rotate, and pull out.  You can then access the soil moisture by observing and feeling the soil samples retrieved in the notches.  See this article for more details [http://www.insideurbangreen.org/2008/08/a-better-way-to-check-soil-moisture.html A Better Way To Check Soil Moisture]
+[[File:Inside_urban_green_soil_probe.jpg|150px]] To use this type of probe, you push into the soil, rotate, and pull out.  You can then access the soil moisture by observing and feeling the soil samples retrieved in the notches.  See this article for more details [http://www.insideurbangreen.org/2008/08/a-better-way-to-check-soil-moisture.html A Better Way To Check Soil Moisture]
 ==Soil cores==

← Older revision	Revision as of 05:20, 10 August 2012
(No difference)