Decagon Devices Environmental Research

Instruments

Matt Galloway Decagon Devices, Inc.

Pullman, WA USA

Sole Distributor : Team Medical & Scientific Sdn. Bhd.

Tel : 03-5122 5108 Email : info@tms-lab.com

Decagon History

Now 100+ employees

Decagon’s Goal

Develop, manufacture and market

innovative instruments for use in environmental research

n Decagon’s assets: Scientific Expertise

Decagon’s Assets: 改善: Kaizen

n Continual improvement: in design, manufacturing, and all processes

Decagon’s Thermal and Electrical Conductivity Probe (TECP): 2007 Mars Lander

TECP objectives

n  Learn more about how heat flows in Martian regolith n  Ground-truth for plentiful remote

sensing data

n  Determine if unfrozen water may exist under sunlit conditions in trench n  Answers: “Can liquid water

occur on Mars?”

n  Study vapor phase water transport n  Examine how ice migrates from

pole to pole Prototype TECP probe

WP4C Dewpoint Water Potential Meter

n Measures Water Potential of Soils, Seeds, Organic Matter, etc.directly MPa and Pf (log base 10 of MPa)

n Easy to use, more robust than thermocouple psychrometers

n Temp. controlled n Range: -0.05 to -300MPa

Chilled-mirror Dewpoint Technique

Infrared Sensor

Optical Sensor

Mirror is chilled until dew is formed. The temperature at which saturation is achieved is determined by observing condensation on a chilled surface (mirror).

Advantages •  Wide measurement range •  Rapid measurement ~ 5 min. •  High reliability •  Low Maintenance

Sample

Mirror

Fan

Moisture Release Curves

pF Plot to get Soil Swelling

y = -17.02x + 7.0381R2 = 0.9889

y = -29.803x + 7.0452R2 = 0.9874

y = -97.468x + 6.8504R2 = 0.96883

3.54

4.55

5.56

6.57

7.5

0 0.05 0.1 0.15 0.2

Water Content (g/g)

Suct

ion

(pF)

L-soilPalousePalouse B

Expansive Soil Classification from

McKeen(1992)

Class Slope Expansion

I > -6 special case

II -6 to -10 high

III -10 to -13 medium

IV -13 to -20 low

V < -20 non-expansive

Vapor Sorption Analyzer (VSA)

20

Range: -10 to -475 MPa. Accuracy: ±1MPa or ±1% Operating Temperature: 15 to 40°C

• Auto-generated moisture release curves • Static humidity feature to watch how soil adsorbs water over time

VSA data

0

5

10

15

20

25

-500 -400 -300 -200 -100 0

Water Potential (Mpa)

Wat

er C

onte

nt (g

/100

g)

BentonitePalouse BNM clayWalla WallaRoyalL-soil

0

5

10

15

20

25

0 0.2 0.4 0.6 0.8 1

Water Activity

Wat

er C

onte

nt (g

/100

g)

BentonitePalouse BNM clayWalla WallaRoyalL-soil

Vapor Sorption Analyzer

Decagon Devices, Inc. Confidential and Proprietary Do Not Copy or Redistribute 22

DVS Change In Mass (ref) Plot

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

4

250 350 450 550 650 750 850

Time/mins

Cha

nge

In M

ass

(%) -

Ref

0

10

20

30

40

50

60

70

80

90

100

Targ

et R

H (%

)

dm - dry Target RH

©  S urface  Measurement  S ystems  Ltd  UK  1996-­‐2007DV S  -­‐  T he  S orption  S olution

Temp: 25.0 °C Meth: polymer f ilm.sao MRef: 2.28063

Static humidity feature to watch water adsorption vs. time

AccuPAR Ceptometer model LP-80

What does the AccuPAR Measure? n  PAR (Photosynthetically Active

Radiation n  LAI (Leaf Area Index) calculated

using PAR measurements above and below the canopy, and using other variables.

Decagon invented this type of instrument in 1988 (Sunread, Sunscan, PAR-80, LP-80)

What is PAR? n  Acronym for Photosynthetically Active Radiation.

n  Defined as the light in the 400 to 700 nm range of the spectrum (visible range).

n  Light that is most

useful to plants for photosynthesis.

n  Expressed by AccuPAR as µmol m-2 s-1, a measure of photon flux density

Electromagnetic Spectrum

Leaf Area Index (LAI)

What is LAI?

n  Defined as: total leaf area per unit ground area

n  Indication of Canopy density, biomass

n  Used to monitor growth, infestation

n  Often used for ground-truthing Remote Sensing LAI data

Calculating LAI

n Above-canopy PAR n Below-canopy PAR n x (leaf distribution parameter) n Zenith angle (automatically calculated) n Fb (fraction of beam radiation)

AccuPAR calculates LAI based on equations from Goudraan, Norman, and Campbell using measured and supplied data:

Comparison Studies

“Comparisons of three Leaf Area Index Meters in a Corn Canopy” by W.W. Wilhelm, K. Ruwe, M.R. Schlemmer in Crop Science 40:1179-1183 (2000)

n  Shows that all three types are similar, AccuPAR/SunScan somewhat better than LAI-2000.

Spectral Reflectance Sensors (SRS) •  NDVI  bands:  630  nm  and  800  nm  center  wavelengths  •  PRI  bands:  532  nm  and  570  nm  center  wavelengths  •  NIST  traceable  calibra5on  stored  onboard  •  Cosine  diffusers  for  hemispherical  measurement  •  20°  sealed  field  stops  for  direc5onal  measurements  •  Dimensions:  43  x  40  x  27  mm  •  Epoxy-­‐sealed  sensor  body  –  robust  design  •  SDI-­‐12  digital  sensor  •  Decagon  Em50  and  CSI  datalogger  compa5ble  

PRI

PRI

ND

VI

ND

VI

Hemispherical view sensors

Directional field stop sensor

Stacked SRS sensors NDVI + PRI

How to Measure NDVI and PRI

PRI

ND

VI

ND

VI

ND

VI

PRI

Only two bands are needed to calculated NDVI or PRI.

Typical canopy reflectance spectrum

redNIR

redNIRNDVIρρρρ

+−

=

Calculating NDVI

NIR

red

•  NDVI is calculated from measurements of percent reflectance (ρ) in the red and near-infrared (NIR) regions of the electromagnetic spectrum.

•  Percent reflectance is the ratio between upwelling (from the canopy) to downwelling (from the sky) radiation. Requires a measurement of both.

•  Red band is related to chlorophyll content (high absorption), NIR band is related to leaf cell structure (high scattering).

NDVI values range from -1 to 1.

Gamon & Surfus (1999) New Phyt.

570531

570531

ρρρρ

+−

=PRI

Calculating PRI

•  PRI (Photochemical Reflectance Index) was designed to estimate Light Use Efficiency (LUE) by detecting changes in the xanthophyll cycle

•  Xanthophyll pigments change rapidly in response to environmental conditions

PRI values range from -1 to 1.

Measurement Considerations

Image credit: Chris Gough

•  Reflectance measurements require a top-down view of the canopy to measure upwelling radiance.

•  Up-looking sensors require unobstructed view of the sky.

•  Dual-view instruments (up/down) are a convenient way of measuring both incident and reflected light for calculating percent reflectance. They also account for changing sky conditions (e.g., clear vs. cloudy sky conditions).

•  SRS are lightweight, low power, and have a small footprint, making them easy to mount almost anywhere.

Downwelling radiation

Upwelling radiation

Leaf Porometer Model SC-1 For measurement of stomatal conductance

• Steady-state technique

• Stomatal conductance is a primary indicator of plant stress under drought conditions

How does it work? n  A chamber with a fixed

diffusion path is clamped to the leaf surface

n  Steady-state technique; measures vapor pressure at two locations in a fixed diffusion path

n  Calculates flux and gradient from the vapor pressure measurements and the known conductance of the diffusion path.

Atmosphere

Desiccant

What can I do with a porometer? n Water use and water balance

n Use conductance with Fick’s law to determine crop transpiration rate

n Develop crop cultivars for dry climates/salt affected soils

n Determine plant water stress in annual and perennial species n Study effects of environmental conditions n Schedule irrigation

n Optimize herbicide uptake n Study uptake of ozone and other pollutants

Case study: Washington State University wheat

•  Researchers using steady state porometer to create drought resistant wheat cultivars – Evaluating physiological response to drought

stress (stomatal closing) – Selecting individuals with optimal response

Case Study: Stress in wine grapes

y = 0.0204x - 12.962R² = 0.5119

-20.0

-18.0

-16.0

-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

0 50 100

150

200

250

300

350

400

450

500

Mid

-day

Le

af W

ater

Pot

entia

l (ba

rs)

Stomatal Conductance (mmol m-2 s-1)

Mini-Disk Infiltrometer For measurement of Soil

Hydraulic Conductivity n  Soil Hydrology Studies n  Erosion Studies n  Classroom Instruction FEATURES: ®  Adjustable suction rate (0.5 to

6cm) ®  Sintered stainless steel disk ®  Removable parts

Dielectric Soil Moisture Sensors

n  Hi-frequency capacitance (FDR) -- Measures the dielectric constant

of the soil

n  Designed to be buried in soil for long-term monitoring of soil moisture

n  Measurement is made by processor inside probe head

Analog soil moisture sensors

10HS: 10 cm probe length, 3-15 VDC — large sample area (~1 liter)

EC-5: 5cm probe length, 2.5-3 VDC — smallest length

MAS-1: 4-20 mA sensor, 5cm probe length — smallest length

Digital Sensors GS3: Water content, EC (0-23 dS/m) and temperature. For soil or soil-less substrates

5TE: Water content, EC (0-23 dS/m) and temperature. For field soils only.

5TM: Water content and temperature. For field soils

All digital sensors are SDI-12 compatible

Applications: Plant available water

Applications: Irrigation Scheduling

Applications: Hydrologic monitoring

Applications: Hazardous waste monitoring

Applications: slope stability

Em50 Data Logger

n  Weatherproof,-40° to 45°C measurement

n  5 ports n  Uses 5 AA alkaline batteries,

low power usage. n  Programmed via RS232 cable

connected to COM Port. n  Measures every minute, then

averages and stores readings according to how it’s programmed. It can store any interval between 1min. and 1 day.

n  Measures other micro-environment sensors that Decagon sells

Storage Capacity:

1MB non-volatile flash (28,672 scans on all 5 ports).

VP3 RH/Temp Sensor and Radiation shield

n  Digital sensor for use with Em50 loggers

n  Measures and logs vapor pressure and temperature with a capacitance sensor and thermistor

n  Should be used with a radiation shield for outdoor use

Temperature Sensor

n Measures from – 40°C to 60°C

n Accuracy: ±0. 5 ° from 5 to 40°C; ±1°C outside this range

n Can be used in air, soil, or liquid. If used in air, a radiation shield should be used.

Leaf Wetness Sensor n  Determines presence and

duration of leaf moisture n  Similar technology to EC-5,

does not require painting or maintenance

n  All probes are calibrated to

same dryness baseline voltage

n  Water condenses and

evaporates from the surface at the same rate as it does on leaves

Leaf Wetness applications

n Disease prediction

MPS-2 Matric Potential Sensor

n For in-situ monitoring of water potential

n Range: -10 to -500 kPa(pF 2 to pF 3.71)

n Uses capacitance method to measure water content of a known ceramic matrix

Sensor Theory

n Measure water content of a known porous material with a pre-established SWCC, giving us matric water potential.

Matrix (Side View) Sensor (Side View)

Confined EM Field

Metal Plate

Metal Plate

MPS-2 Advantages

n  No maintenance n  Good accuracy in plant-available

range n  Each sensor pre-calibrated n  Also measures Soil temperature

Water Potential is a better indicator of plant available water than water content

Pyranometer / PAR sensor n  Manufactured by Apogee

Instruments n  Configured to connect to

our Em50 n  Measures total solar

radiation (W/m2), PAR sensor measures µmol/m2/s

n  Important for energy balance studies and micro-climate monitoring.

n  Comes with leveling plate

ECRN-100 Rain Gauge

n Resolution : 0.2 mm

n Double-spoon tipping

bucket

Cup Anemometer

•  For use with Em50 only, measures both speed and direction

Em50R Radio-enabled Logger

n  Any number of Em50Rs can transmit to one Data Station or Rm1.

n  Range is from 1 to 3 km, depending on interference. Range can be increased with use of antenna.

n  Transmits data when measurement is taken

Same specifications as normal Em50, only Em50R has a radio transmitter that sends collected data via telemetry

DataStation

•  Collects data from any number of Em50Rs

•  Can operate on solar power or AC power

•  Download direct to PC or PDA at your convenience

•  Has Radio Telemetry test capability to help with placing Em50R loggers.

Em50R/DataStation logging scenario

Em50G: What is it?

GSM-enabled logger, delivers data via GSM providers to Decagon’s server Data is available at any internet connection

Why the Em50G?

• 2.4 Ghz Radio can be problematic (range, wifi interference) • Single point remote locations • Ease of data acquisition via internet

Computer + Software + Internet Em50G

Logger + Sensors

GSM/GPRS Cell Tower

Internet

Decagon Internet Server

64

How does it work?

ECHO Utility

You can: n  Configure ports n  Name logger n  Set logging interval n  Download data n  Scan ports

- Does not graph - Cannot apply

calibrations in program

Free software that comes with any Em50 and Em5b purchase

CTD (conductivity, temp., depth sensor)

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Water Depth Range 0 to 3.5 m Accuracy ±0.2 % of span Resolution 1 mm Electrical Conductivity Range 0 to 120 dS/m (mS/cm) Accuracy ±5% of reading Resolution 1.2% of reading Temperature Range -40 to + 50 °C Accuracy ±1 °C Resolution 0.1 °C

CTD Uses

n Streambeds

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•  Piezometer wells

ES-2 EC and T sensor

n  For monitoring EC and temperature in liquid water

Range: Electrical Conductivity: 0 to 120 dS/m Temperature: -40 to 50°C Resolution: Electrical Conductivity: 0.001 dS/m Temperature: 0.1°C Accuracy: Electrical Conductivity: + 0.01 dS/m or + 10 % (whichever is greater) Temperature: + 1°C

Drain Gauge: Passive Capillary Lysimeter

n Purpose: to measure deep drainage (flux and solute analysis) below the root zone

Model G3 Model G2

Drain Gauge G-2: How it works

1.  Drain Gauge is installed below the root zone

2.  Water travels through divergence control tube, then through wick to measurement chamber.

3.  Water level is continuously monitored by depth sensor inside chamber. When 31ml of water fills the chamber, it empties via a siphon into a collection chamber. Each siphon event corresponds to 1mm of infiltration.

4.  Water samples can be extracted from collection chamber using a syringe.

5.  Excess water exits through the overflow port, leaving a constant volume in the sampling reservoir.

Drain Gauge G-2: Chamber

Drainage Data Drain Gauge data

(potato field, S. Idaho)

0

100

200

300

400

500

600

700

800

900

55 60 65 70 75 80 85

time(days)

drai

n ga

uge

outp

ut (m

V)

Drain Gauge G3

n  Sampling Reservoir Volume: 3 L n  Accuracy: ± 2% of full scale n  Total Length: 1.5m n  Divergence Control Tube (DCT) Length :60 cm n  Construction Material: Stainless Steel or PVC

DCT

Decagon Devices, Inc. Confidential and Proprietary Do Not Copy or Redistribute 73

•  Measure deep drainage flux (past the root zone) •  Analyze water samples •  Also measures EC and Temp. •  Sealed lower portion

Decagon Devices, Inc. Confidential and Proprietary Do Not Copy or Redistribute 74

Thermal Conductivity, Thermal Diffusivity, Thermal Resistivity and Specific Heat Capacity.

n Extended temperature range: -50 to 150°C.

n Data storage. n Smart sensors n Can be used with

liquid samples.

PRO

KD2 Pro Applications:

n  Soil thermal properties (fire, sun)

KD2 Pro Applications:

n Insulation

KD2 Pro Applications:

n Nanofluids

KD2 Pro Applications: n Thermal

Backfill

KD2 Pro Applications:

n Petroleum products