Calibration of Hand-Held Moisture Meters

Transcription

2009 Calibration of Hand-Held Moisture Meters (Resistance/Capacitance)
when used with 9Wood’s Particleboard Products
Test Evaluation Report Jonathan C. Gates
9Wood, Inc.
August 2009
[CALIBRATION OF HAND-HELD MOISTURE METERS (RESISTANCE/CAPACITANCE)
WHEN USED WITH 9WOOD’S PARTICLEBOARD PRODUCTS]
August 2009
Abstract:
This report analyzes the accuracy and precision of two types of Electrical method
moisture meters (Resistance and Capacitance type). Both the Lignomat Mini-Ligno DX and
Lignomat Scanner SD moisture meter were used to collect moisture content values on Vesta
FR Flakeboard Particleboard and Standard (non-FR) Flakeboard Particleboard. The meter
readings for each panel were compared against their Oven-Dry moisture content to find the
most accurate, reproducible, and practical moisture meter. A total of 6,750 moisture meter
readings were taken on 150 particleboard panels. From the collected data, an equilibrium/
acclimation chart was created with the preferred moisture meter [Mini-Ligno DX (Short Pin /
Setting 3 / Taken from the face veneer)]. This chart and preferred moisture meter will help in
determining a fully acclimated panel for installation.
9Wood, Inc. | 0BAbstract:
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Table of Contents:
Page Number
Abstract ..................................................................................................................................................................... ii
Introduction .............................................................................................................................................................. 1
Literature Review ................................................................................................................................................... 1-2
Materials and Methodology................................................................................................................................... 2-8
Figure 1: Picture of Moisture Meters .................................................................................................................................................... 2
Figure 2: Picture of Oven ...................................................................................................................................................................... 2
Figure 3: Dimensions of Sample Board ............................................................................................................................................... 3
Figure 4: Moisture Meter Placement .................................................................................................................................................... 4
Figure 5: Mini-Ligno DX Grid Placement .............................................................................................................................................. 4
Table 1: Temperature and %RH of Conditioning Rooms .................................................................................................................... 5
Table 2: Sample Board Weights in Conditioning................................................................................................................................. 5
Figure 6: Picture of Labeled Sample Board ........................................................................................................................................ 6
Figure 7: Picture of Meters in Use ........................................................................................................................................................ 7
Figure 8: Picture of Weight Scale ......................................................................................................................................................... 7
Equation 1: Oven-Dry MC Equation ..................................................................................................................................................... 7
Table 3: Wood Handbook’s Table of MC of Wood in Equilibrium ...................................................................................................... 8
Results and Discussion ....................................................................................................................................... 8-12
Table 4: Average %MC of Each Conditioning Chamber and Particleboard Type.............................................................................. 8
Figure 9: Graph of Both Meter’s Most Accurate Meter Reading and Corresponding Oven-Dry MCs .............................................. 9
Figure 10: Graph of Meter Readings vs. Corresponding Oven-Dry MCs ......................................................................................... 10
Table 5: %MC Correction Chart for Vesta FR Flakeboard Particleboard .......................................................................................... 10
Equation 2: Equation used to Calculate Actual %MC in Vesta FR Flakeboard Particleboard ......................................................... 10
Table 6: Acclimation/ Equilibrium Chart for Vesta FR Flakeboard Particleboard ............................................................................. 11
Figure 11: Acclimation/ Equilibrium Graph for Vesta FR Flakeboard Particleboard ........................................................................ 12
Conclusion .............................................................................................................................................................. 13
Literature Cited ....................................................................................................................................................... 14
Appendices ........................................................................................................................................................ 15-45
Appendix I: Scanner SD (Setting 65) Test Data ........................................................................................................................... 16-17
Appendix II: Scanner SD (Setting 75) Test Data ........................................................................................................................... 18-19
Appendix III: Scanner SD (Setting 85) Test Data .......................................................................................................................... 20-21
Appendix IV: Mini-Ligno DX (Short Pin / Setting 1) Test Data ...................................................................................................... 22-23
Appendix V: Mini-Ligno DX (Short Pin / Setting 2) Test Data ...................................................................................................... 24-25
Appendix VI: Mini-Ligno DX (Short Pin / Setting 3) Test Data ..................................................................................................... 26-27
Appendix VII: Mini-Ligno DX (Long Pin / Setting 1) Test Data .................................................................................................... 28-29
Appendix VIII: Mini-Ligno DX (Long Pin / Setting 2) Test Data ................................................................................................... 30-31
Appendix IX: Mini-Ligno DX (Long Pin / Setting 3) Test Data ..................................................................................................... 32-33
Appendix X: Oven-Dry Moisture Contents .................................................................................................................................... 34-35
Appendix XI: Comparison Between Each MC Method and Setting ............................................................................................. 36-39
Appendix XII: Standard (non-FR) Flakeboard Particleboard Graph Correlation Series ............................................................. 40-42
Appendix XIII: Vesta FR Flakeboard Particleboard Graph Correlation Series ............................................................................ 43-45
9Wood, Inc. | 0BAbstract:
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Introduction: Moisture content (MC) has the greatest effect on wood properties. It can vary widely
depending on the environment, the species of the wood, and the history of the wood. Effective
use of wood and wood-base materials therefore requires efficient and reliable methods of
measuring wood moisture (James, 1988). Oven-Drying and Electrical methods are two
methods most commonly used to determine MC. The Oven-Drying method is the most
universally accepted technique, but isn’t always practical. Electrical methods on the other
hand use the relationships between MC and measurable electrical properties of wood, such as
conductivity (resistivity), or a dielectric constant (capacitance). This method is quick and
convenient, but requires the moisture meter to be correctly calibrated to the product.
In this report, two types of Electrical method moisture meters (resistance and
capacitance type) were tested against the Oven-Dry method on both Vesta Fire Retardant (FR)
Flakeboard Particleboard and Standard (non-FR) Flakeboard Particleboard with a face and
back veneer. The purpose of the test was designed to examine which meter (resistance or
capacitance) and setting (see 6.2.5 on page 3) would produce the most accurate means of
determining if Vesta FR Flakeboard Particleboard panels (with a face and back veneer) have
reached equilibrium moisture content (EMC) after moving from one environment to another.
The test also examined the difference in measurable MC between Standard (non-FR)
Flakeboard Particleboard and Vesta FR Flakeboard Particleboard.
Literature Review: In accordance to building codes and various standards, Flakeboard Vesta FR
Particleboard is treated with fire-retardant chemicals. These chemicals are used to reduce
and/or prevent the spread of flame in the case of a fire. Flame-retardant treatment of wood
generally improves the products performance during a fire by reducing the amount of
flammable volatiles released during fire exposure and/or by reducing the effective heat of
combustion. Both results have the effect of reducing the heat release rate (HRR), particularly
during the initial stages of fire, and thus consequently reducing the rate of flame spread over
the surface. The wood may then self-extinguish when the primary heat source is removed
(Wood Handbook, 1999).
In the case of particleboard, inorganic salt crystals are generally used in fire-retardancy.
Although these chemicals help in the prevention of fire, they pose many problems when
determining the MC of the panel. The electrical current is altered by the nature of the inorganic
salts when using an Electrical method moisture meter. This false MC can be confusing to the
user, and therefore calibration is required to obtain a correct reading. The fire-retardant
chemical also poses a problem when using the Oven-Dry method. A panel with a chemical
impregnant that is volatile at oven temperatures will evaporate during ovendrying, and the
resulting weight loss can be misinterpreted as due to evaporated water. An impregnant that is
nonvolatile will remain in the panel and increase the apparent ovendry weight of the wood
(James, 1988). The chemical used in Flakeboard Vesta FR Particleboard is extremely volatile
9Wood, Inc. | 1BIntroduction:
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at high temperatures and when exposed to such heat, water is released, thus increasing the
apparent MC of the panel.
Due to this distortion in meter readings and false ovendry MC in Fire-Retardant panels,
it is nearly impossible to obtain the true MC of the panel. Consequently, it is extremely
important to calibrate the moisture meters to a given product as well as create an equilibrium/
acclimation chart. By doing this, it can be assured that the panel is at equilibrium with its
environment when the target meter reading (from the acclimation chart) and actual meter
reading become relatively equivalent.
Methodology: 1. Referenced Documents
1.1. ASTM Standards
• D 4442 Test Methods for Direct Moisture Content Measurement of Wood and
Wood-Based Materials.
• D 4444 Standard Test Methods for Use and Calibration of Hand-Held Moisture
Meters.
• D 4933 Guide for Moisture Conditioning of Wood and Wood-Based Materials.
2. Summary of Test Method
2.1. 150 samples (75 Vesta FR Particleboard samples, and 75 Standard non-FR
Particleboard samples) were conditioned in an ASTM standards chamber, a Hot/Dry
chamber, a Hot/Wet chamber, a Cold chamber, and an ambient (outside) chamber
until fully acclimated. MC measurements were taken with a Lignomat Mini-Ligno DX
“pin style” (resistance) moisture meter and a Scanner SD “pinless style” (capacitance)
moisture meter at multiple settings. Next, calibration of these readings were done using
an ASTM D 4442 oven dry method (method A) to determine which moisture meter and
setting number produced the most accurate measurements. After an accurate meter
and setting number was determined, an equilibrium/acclimation chart was created.
3. Significance and Use
3.1. Refer to ASTM D 4442, D 4444, and D 4933.
4. Apparatus
4.1. Lignomat Mini-Ligno DX moisture meter (provided by 9Wood) (Figure 1).
4.2. Lignomat Scanner SD moisture meter (provided by Lignomat) (Figure 1).
4.3. Refer to ASTM D 4442 & D 4933 for apparatus required for oven dry method.
4.3.1. Actual oven used in oven dry test is depicted in Figure 2.
Figure 1: Mini-Ligno DX (left) and the Scanner SD (right)
Figure 2: Oven for the Oven-Dry Test.
9Wood, Inc. | 3BMethodology:
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5. Test Materials
5.1. Wood:
5.1.1. Prisms were made from ¾” Flakeboard Vesta FR Particleboard and ¾”
Flakeboard Standard (non FR) Particleboard with a face and back veneer.
5.1.2. Prisms were 4” (101.6mm) wide by 6” (152.4mm) long by 3/4" (19mm) thick
(Figure 3).
6. Sampling
6.1. Constants:
6.1.1. 3/4” particleboard with face and back wood veneers.
6.1.2. Temperature at time of moisture meter readings (65˚F).
6.1.3. Direction of Veneer grain in relation to the direction of the moisture meter’s pins
or plate (parallel correlation).
6.1.4. Tested veneer (plain sliced cherry).
6.2. Variables:
6.2.1. Particleboard (Flakeboard Vesta FR Particleboard and Standard non-FR
Particleboard).
6.2.2. Moisture Meter (Lignomat’s Mini-Ligno DX and Scanner SD).
6.2.3. Mini-Ligno DX pin length (short and long).
6.2.4. Scanner SD penetration depth (1/4” and 3/4").
6.2.5. Moisture meter setting number (1, 2, and 3 on the Mini-Ligno DX and 65, 75, and
85 on the Scanner SD).
6.2.6. Conditioning (ASTM, Hot/Dry, Hot/Wet, Cold, Outside/Ambient).
6.3. 15 replications for each variable/combination were performed.
7. Test Specimen
4” Grain Direction
¾” 6”
Figure 3: Dimensions of Sample Board
7.1. A total of 27 readings from the Mini-Ligno DX moisture meter were taken. 18 readings
were taken with the short pin (3 readings from each setting were taken on the face
veneer and 3 from each setting were taken from the edge (center of thickness) of each
panel). 9 readings were taken with the long pin [3 readings from each setting were
taken on the edge (center of thickness) of each panel].
7.1.1. Note: Long pins were not used on face veneer because of the amount of force
required to drive the pins. The application was too impractical to keep as a
variable.
7.2. A total of 6 readings from the Scanner SD moisture meter were taken (3 readings with
each depth setting from the face veneer) on each sample board.
7.3. The position of each Moisture Meter was strategically placed on the panel (Figures 4 &
5).
7.3.1. Meter readings for the Mini-Ligno DX were taken by following a simple grid
pattern (Refer to Figure 5).
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Mini‐Ligno DX
Scanner SD
Grain Direction Grain Direction Figure 4: Depiction of the moisture meter placement for the Mini-Ligno DX (left) and the Scanner
SD (right) in relation to the grain direction of the veneer.
Grain Direction
Setting 3 Placement of Pins
Setting 1 Setting 3 Setting 2
Setting 1
Setting 2
Figure 5: Depiction of Mini-Ligno’s pin placement. Readings taken from Setting 1 are shown in
Blue, Setting 2 are in Red, and Setting 3 are in Green.
7.4. A total of 150 samples were tested.
7.4.1. 15 samples consisted of Flakeboard Vesta FR Particleboard, conditioned in the
ASTM chamber. 27 readings from the Mini-Ligno DX moisture meter and 6 from
the Scanner SD moisture meter were taken.
Hot/Dry chamber. 27 readings from the Mini-Ligno DX moisture meter and 6
from the Scanner SD moisture meter were taken.
Hot/Wet chamber. 27 readings from the Mini-Ligno DX moisture meter and 6
Cold chamber. 27 readings from the Mini-Ligno DX moisture meter and 6 from
the Scanner SD moisture meter were taken.
7.4.5. 15 samples consisted of Flakeboard Vesta FR Particleboard, conditioned
Outside in ambient air. 27 readings from the Mini-Ligno DX moisture meter and 6
7.4.6. 15 samples consisted of Standard (non-FR) Flakeboard Particleboard,
conditioned in the ASTM chamber. 27 readings from the Mini-Ligno DX moisture
meter and 6 from the Scanner SD moisture meter were taken.
conditioned in the Hot/Dry chamber. 27 readings from the Mini-Ligno DX
moisture meter and 6 from the Scanner SD moisture meter were taken.
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conditioned in the Hot/Wet chamber. 27 readings from the Mini-Ligno DX
conditioned in the Cold chamber. 27 readings from the Mini-Ligno DX moisture
meter and 6 from the Scanner SD moisture meter were taken.
conditioned Outside in ambient air. 27 readings from the Mini-Ligno DX
8. Conditioning
8.1. The panels were conditioned in an ASTM chamber, Hot/Dry chamber, Hot/Wet
chamber, Cold chamber, and Outside in ambient air.
Conditioning Chamber Temperature Relative Humidity (°C/°F) (%) ASTM 20/68 65 Hot/Dry Hot/Wet 30/86 30/86 20 90 Cold 5/41 80 Outside/Ambient 23/73 51 Table 1: Temperature and %RH of each conditioning chamber.
8.2.
Samples were left to acclimate until a steady weight was reached (Table 2).
Sample Board Weight (grams) in Conditioning Condition Board # STD ASTM Date 15‐Jul 16‐Jul 17‐Jul 18‐Jul 19‐Jul 20‐Jul 21‐Jul 22‐Jul 13 14 15 211.60 209.22 224.05 212.07 209.45 229.37 212.37 209.59 229.56 ‐ ‐ ‐ ‐ ‐ ‐ 212.83 209.83 229.85 212.90 209.78 229.88 Tested Tested Tested FR Hot/Dry 26 27 28 226.23 220.64 221.22 223.30 217.26 217.96 222.20 215.98 216.66 ‐ ‐ ‐ ‐ ‐ ‐ 220.44 214.04 214.73 219.62 213.13 213.66 219.54 213.09 213.60 FR Hot/Wet 31 32 33 217.30 216.19 216.35 219.60 218.42 218.50 220.69 219.45 219.53 ‐ ‐ ‐ ‐ ‐ ‐ 222.22 220.93 221.02 223.31 221.96 222.05 223.58 222.28 222.35 STD Cold 47 48 49 206.90 206.53 219.55 208.41 207.88 221.18 209.43 208.87 222.11 ‐ ‐ ‐ ‐ ‐ ‐ 211.08 210.36 223.52 211.37 210.49 223.78 Tested Tested Tested FR Outside 73 74 75 218.27 218.74 218.58 ‐ ‐ 218.23 218.26 224.56 225.32 225.38 ‐ ‐ 225.41 225.50 219.49 219.97 219.85 ‐ ‐ 219.56 219.58 Table 2: Sample board weights during the process of conditioning.
Tested Tested Tested 9Wood, Inc. | 3BMethodology:
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9. Procedure
9.1. Various Flakeboard Vesta FR Particleboard and Flakeboard Standard (non-FR)
Particleboard panels were obtained from 9Wood’s manufacturing facility and cut into
designated dimensions (refer to Figure 3).
9.2. Sample boards were labeled with a number (for reference) and their particleboard
core (refer to 7.4 for various sample boards). An example is shown below in Figure 6.
Figure 6: Picture of a correctly labeled sample board.
9.3.
15 samples of each particleboard type were then placed in one of the five
conditioning rooms to acclimate until stable weights were reached (Table 1 & 2).
9.4. Once acclimation was reached, the boards were transferred to plastic bags to
prevent moisture gain/ loss and to allow for cooling.
9.5. Boards were then tested using the following procedure. (Refer to Figure 7 depiction
of meters in use).
9.5.1. One by one, each sample board was removed from the plastic bag and with the
use of the Scanner SD (Setting 65, penetration depth 1/4") three readings from
the face of the panel were taken and then placed into another bag.
9.5.2. The penetration depth on the Meter was then changed to 3/4" and three more
readings from the face of the panel were taken.
9.5.2.1. Note: The samples were placed on spacers to prevent the table surface
from interfering with the meter reading.
9.5.3. Using the same process, three meter readings with Setting 75 and 85 were then
taken with the Scanner SD.
9.5.4. After all the meter readings with the Scanner SD were taken, each sample board
was removed from the plastic bag and with the use of the Mini-Ligno DX (Short
pin / Setting 1) three readings from the face and edge were taken using the grid
pattern shown in Figure 4 and then placed into another bag.
taken on the face and edge of the panel with the short pin.
9.5.6. After all Mini-Ligno DX (Short pin) readings were taken, the short pins were
changed out and replaced with the longer pins.
9.5.7. One by one, each sample board was removed from the plastic bag and with the
use of the Mini-Lingo DX (Long pin, setting 1) three readings from the edge of
the panel were taken and then placed into another bag.
taken with the long pin.
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Figure 7: Picture of each meter type. Scanner SD (left), Mini-Ligno DX Short Pin (middle), MiniLigno DX Long Pin (right).
9.5.9. After all meter readings were taken, the boards were weighed and then placed
into the oven to dry for an Oven-Dry MC (Figure 8).
Oven Dry %MC
Wet W
– Oven DryW
Oven Dry W
100
Equation 1: Formula used to derive Oven-Dry Moisture
Content.
Figure 8: Picture of device used to weigh samples.
9.5.10. The sample boards were left to dry for approximately 24 hours. Moisture
content was determined using the Oven-Dry method (refer to Equation 1).
9.6. The data were analyzed to find the difference between Standard (non-FR)
Flakeboard Particleboard and Vesta FR Flakeboard Particleboard.
9.7. Each data set from the tested moisture meters was then graphed and a regression
line was fitted to the data points. From here, the moisture meter with the most
accurate MC readings and highest R2 value (best correlation) for Vesta FR
Particleboard was determined.
9.8. Once the appropriate meter was determined, an equilibrium/ acclimation chart was
created using the relative humidity and temperature from each conditioning room.
Assumptions were drawn with help from Table 3-4 of the Wood Handbook (Table 3).
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Table 3: Table 3-4 from Wood Handbook that was used to extrapolate data in equilibrium/
acclimation chart.
9.9.
Conclusions were drawn from results.
Results and Discussion: There was a common difference between Standard non-FR Flakeboard Particleboard
and Vesta FR Flakeboard Particleboard. On average, Vesta FR Flakeboard Particleboard had
an apparent 3.3% higher Oven-Dry MC over Standard Particleboard.
Average Percent Moisture Contents for Each Conditioning Chamber and Particleboard Type Particleboard type Standard (non‐FR) Vesta FR Range ASTM 9.5% 13.1% 3.7% Conditioning Chamber Hot/Dry Hot/Wet Cold 6.1% 12.8% 11.3% 8.5% 16.1% 14.9% 2.4% 3.3% 3.6% Outside 9.1% 12.6% 3.5% Table 4: Comparison of average Oven-Dry %MC between Standard (non-FR) Particleboard and
Vesta FR Particleboard after conditioned in each chamber.
9Wood, Inc. | 4BResults and Discussion: 8
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Each Moisture Meter (resistance and capacitance type) and setting varied widely in
moisture content readings (refer to Figure 9). The Scanner SD was the quickest and easiest
meter to use, but showed minimal signs of accuracy and precision. The Mini-Ligno DX (long
pins installed) presented the highest accuracy and precision, but was impractical because
edge of board entry can be restricted during commercial use. The Mini-Ligno DX (short pins
installed) on the other hand had high signs of accuracy, precision, and practicality. Later
investigation confirmed that the Mini-Ligno DX equipped with the short pins on “Setting 3”
taken from the face veneer is the best meter and setting for commercial use (Figure 10).
20.0%
18.0%
y = 0.0067x + 0.0601
R² = 0.9373
16.0%
Vesta Oven‐Dry %MC
14.0%
y = 0.0055x + 0.0578
R² = 0.9749
12.0%
10.0%
8.0%
6.0%
4.0%
2.0%
0.0%
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
Meter Reading
Scanner SD (3/4") Setting 65
Mini‐Ligno DX (Short pin) Setting 3
Linear (Scanner SD (3/4") Setting 65)
Linear (Mini‐Ligno DX (Short pin) Setting 3)
Figure 9: Graph that depicts each meter (Mini‐Ligno DX and Scanner SD) and their corresponding most accurate setting. Meter readings are fitted against the Oven‐Dry MC of Vesta FR Flakeboard Particleboard. 9Wood, Inc. | 4BResults and Discussion: 9
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18.0%
16.0%
14.0%
Vesta Oven‐Dry %MC
12.0%
10.0%
8.0%
6.0%
4.0%
y = 0.0072x + 0.0706
R² = 0.9748
y = 0.0065x + 0.0633
R² = 0.9751
2.0%
y = 0.0055x + 0.0578
R² = 0.9749
0.0%
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
MiniLigno DX Meter Reading
Short Pin (Face) Setting 1
Linear (Short Pin (Face) Setting 1)
Figure 10: Vesta FR Flakeboard Particleboard and corresponding Mini-Ligno DX %MC (Short
Pin/Taken from the face veneer) fitted against Oven-Dry %MC.
Note: The complete set of data tables and corresponding graphs are shown in Appendix I – IX & XIII.
A correction chart and equation to find the actual %MC was created by taking the linear
regression of the Mini-Ligno DX (Short Pin/ Setting 3/ taken from the face veneer) and the
relationship between Standard (non-FR) Particleboard and Vesta FR Particleboard (refer to
Table 5 and Equation 2).
Meter Reading 4 Actual %MC 5.4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 5.9 6.3 6.8 7.3 7.7 8.2 8.7 9.2 9.6 10.1 10.6 11.1 11.5 12.0 12.5 13.0 Table 5: Correction Chart for the Mini-Ligno DX (Short Pin / Setting 3 / Taken from the face veneer)
when tested on Flakeboard’s Vesta FR Particleboard.
August 2009
%
.
.
.
.
Equation 2: Meter correction equation used to calculate actual %MC in Vesta FR Flakeboard
Particleboard with a face and back veneer while using the Mini-Ligno DX (Short Pin / Setting 3 /
Taken from face veneer).
The previous formula and table will only be helpful if the installer/user desires the true
MC of the Vesta FR Flakeboard Particleboard. However, since the purpose of the test was
designed to examine which meter (resistance or capacitance) and setting would produce an
accurate means of determining fully acclimated Vesta FR Flakeboard Particleboard panels with
a face and back veneer, the actual MC is unneeded. All that is necessary is a highly precise
Moisture Meter with an equilibrium/ acclimation chart adjusted to the reading from the Meter
(refer to Table 6 and Figure 11). This set of equipment assures the installer that the panels are
fully acclimated to their environment and ready for installation.
Temperature (°F) Mini‐Lingo DX meter readings at various relative humidity values 40 20% 50% 65% 80% 90% 5.0 13.0
14.1
17.1 18.7
5.0 13.0
14.1
17.0 18.6
5.0 12.9
14.0
16.8 18.5
4.9 12.8
13.8
16.6 18.3
4.8 12.6
13.5
16.3 17.9
4.7 12.4
13.3
16.0 17.6
4.6 12.2
13.0
15.7 17.3
50 60 70 80 90 100 Table 6: Acclimation/Equilibrium (EMC) chart for Vesta FR Flakeboard Particleboard when using
Mini-Ligno DX (Short Pin / Setting 3 / Taken from the face veneer).
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20.0
18.0
16.0
Mini‐Ligno DX Meter Reading
14.0
12.0
10.0
8.0
6.0
4.0
2.0
0.0
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Relative Humidity
40 Deg. F
70 Deg. F
100 Deg. F
Figure 11: Acclimation/ Equilibrium (EMC) graph for Vesta FR Flakeboard Particleboard when
using Mini-Ligno DX (Short Pin / Setting 3 / Taken from the face veneer).
August 2009
Conclusion: This study demonstrates that hand held moisture meters can be a useful tool for
estimating the MC of laminated particleboard products. Although both meters presented
applicable results, the Mini-Ligno DX (Short Pin / Setting 3 / Taken on the face veneer) in
particular had the greatest signs of accuracy, reproducibility, and practicality. By using this
meter and the equilibrium/ acclimation chart, board MC stabilization (EMC) can be easily
predicted.
To obtain desirable results when measuring panel EMC, the following steps must be
preformed:
1. Place the panels in the installation environment. Position them with spaces to allow free
air flow around all surfaces of the panel. Stabilize the installation environment to a
steady temperature and relative humidity within acceptable parameters (refer to
Architectural Woodwork Standards; published by AWI). Measure and record the
relative humidity and temperature of the room.
2. Use the equilibrium/acclimation chart or graph to estimate the target Mini-Ligno DX
meter reading for the given temperature and relative humidity.
3. Three readings from the back of the panel (non decorative side) are to be average from
the Mini-Ligno DX moisture meter while on “Setting 3” with the short pins installed.
4. Repeat step 3 over a few days until a steady meter reading has been collected. The
reading should correspond to the chart’s meter reading (from step 2). If not, let the
panels acclimate for a longer period of time. Note this step could take a while before
completed.
a. Acclimation may take only a few days if the initial readings are close to the
target. It may take a week or more for the panels to make a large change in
moisture content.
5. Once fully acclimated, the panels are ready to be installed. Premature installation could
lead to panel distortion (warp) due to dimensional changes induced by moisture loss or
gain.
9Wood, Inc. | 5BConclusion:
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Literature Cited:
Forest Products Laboratory. 1999. Wood handbook—Wood as an engineering material. Gen.
Tech. Rep. FPL GTR–113. Madison, WI: U.S. Department of Agriculture, Forest Service,
Forest Products Laboratory. 463 p.
James, William L. Electric moisture meters for wood. Gen. Tech. Rep. FPL-GTR-6. Madison,
WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory;
1988. 17 p.
9Wood, Inc. | 6BLiterature Cited:
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9WOOD, INC.
Appendices:
Copy of Test Data and Graphs
Test Evaluation Report
Jonathan C. Gates
August, 2009
9Wood, Inc. | 7BAppendices:
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Appendix I: Scanner SD (Setting 65) Test Data
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Appendix II: Scanner SD (Setting 75) Test Data
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Appendix III: Scanner SD (Setting 85) Test Data
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Appendix IV: Mini-Ligno (Short Pin / Setting 1) Test Data
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Appendix V: Mini-Lingo DX (Short Pin / Setting 2) Test Data
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25
August 2009
Appendix VI: Mini-Ligno (Short Pin / Setting 3) Test Data
26
August 2009
27
August 2009
Appendix VII: Mini-Ligno DX (Long Pin / Setting 1) Test Data
28
August 2009
29
August 2009
Appendix VIII: Mini-Ligno DX (Long Pin / Setting 2) Test Data
30
August 2009
31
August 2009
Appendix IX: Mini‐Ligno DX (Long Pin / Setting 3) Test Data 9Wood, Inc. | 7BAppendices:
32
August 2009
33
Appendix X: Oven Dry Moisture Contents: August 2009
34
August 2009
35
August 2009
Appendix XI: Comparison between each Moisture Content method and setting 9Wood, Inc. | 7BAppendices:
36
August 2009
37
August 2009
38
August 2009
39
August 2009
Appendix XII: Standard (non‐FR) Flakeboard Particleboard Graph Correlation Series Standard Particleboard and corresponding MiniLigno DX %MC (Short Pin/ Taken from Panel Face) fitted against Oven‐Dry %MC
14.0%
y = 0.0051x + 0.0412
R² = 0.9124
y = 0.0058x + 0.0464
R² = 0.9253
12.0%
10.0%
Oven‐Dry %MC
y = 0.0044x + 0.0366
R² = 0.9114
8.0%
6.0%
4.0%
2.0%
0.0%
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
Standard Particleboard and corresponding MiniLigno DX %MC (Short Pin/ Taken from Panel Edge) fitted against Oven‐Dry %MC
14.0%
y = 0.0067x + 0.0388
R² = 0.9587
y = 0.0064x + 0.0281
R² = 0.9558
12.0%
y = 0.0054x + 0.0219
R² = 0.9558
Oven‐Dry %MC
10.0%
8.0%
6.0%
4.0%
2.0%
0.0%
0.0
5.0
Short Pin (Edge) Setting 1
10.0
15.0
20.0
25.0
40
August 2009
Standard Particleboard and corresponding MiniLigno DX %MC (Long Pin/ Taken from Panel Edge) fitted against Oven‐Dry %MC
14.0%
y = 0.0066x + 0.0176
R² = 0.9769
y = 0.006x + 0.0063
R² = 0.9682
12.0%
10.0%
Oven‐Dry %MC
y = 0.0072x + 0.0273
R² = 0.9695
8.0%
6.0%
4.0%
2.0%
0.0%
0.0
5.0
10.0
15.0
MiniLigno DXMeter Reading
Long Pin (Edge) Setting 2
Linear (Long Pin (Edge) Setting 2)
20.0
25.0
Standard Particleboard and corresponding Scanner SD %MC (1/4" Depth of Penetration/ Taken from Panel Face) fitted against Oven‐Dry %MC
18.0%
y = 0.0021x + 0.0674
R² = 0.7478
16.0%
y = 0.0023x + 0.0675
R² = 0.7683
14.0%
y = 0.0018x + 0.067
R² = 0.7231
Oven‐Dry %MC
12.0%
10.0%
8.0%
6.0%
4.0%
2.0%
0.0%
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
Scanner SD Meter Reading
41
50.0
August 2009
Standard Particleboard and corresponding Scanner SD %MC (3/4" Depth of Penetration/ Taken from Panel Face) fitted against Oven‐Dry %MC
18.0%
16.0%
y = 0.0032x + 0.0621
R² = 0.8346
14.0%
y = 0.003x + 0.0615
R² = 0.8196
y = 0.002x + 0.067
R² = 0.7137
Oven‐Dry %MC
12.0%
10.0%
8.0%
6.0%
4.0%
2.0%
0.0%
0.0
10.0
20.0
30.0
40.0
50.0
42
60.0
August 2009
Appendix XIII: Vesta FR Flakeboard Particleboard Graph Correlation Series Vesta FR Particleboard and corresponding MiniLigno DX %MC (Short Pin/ Taken from Panel Face) fitted against Oven‐Dry %MC
18.0%
y = 0.0072x + 0.0706 y = 0.0065x + 0.0633 y = 0.0055x + 0.0578
R² = 0.9751
R² = 0.9749
R² = 0.9748
16.0%
14.0%
Oven‐Dry %MC
12.0%
10.0%
8.0%
6.0%
4.0%
2.0%
0.0%
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
Vesta FR Particleboard and corresponding MiniLigno DX %MC (Short Pin/ Taken from Panel Edge) fitted against Oven‐Dry %MC
18.0%
y = 0.0086x + 0.0685
R² = 0.9793
16.0%
y = 0.0075x + 0.0614
R² = 0.9815
y = 0.0065x + 0.0542
R² = 0.9818
14.0%
Oven‐Dry %MC
12.0%
10.0%
8.0%
6.0%
4.0%
2.0%
0.0%
0.0
2.0
4.0
Linear (Short Pin (Edge) Setting 1)
6.0
8.0
10.0
12.0
14.0
16.0
18.0
43
August 2009
Vesta FR Particleboard and corresponding MiniLigno DX %MC (Long Pin/ Taken from Panel Edge) fitted against Oven‐Dry %MC
18.0%
y = 0.0078x + 0.0695
R² = 0.9803
16.0%
y = 0.0069x + 0.0628 y = 0.006x + 0.0555
R² = 0.9859
R² = 0.9871
14.0%
Oven‐Dry %MC
12.0%
10.0%
8.0%
6.0%
4.0%
2.0%
0.0%
0.0
2.0
4.0
6.0
10.0
12.0
14.0
16.0
18.0
20.0
8.0
Vesta FR Particleboard and corresponding Scanner SD %MC (1/4" Depth of Penetration/ Taken from Panel Face) fitted against Oven‐Dry %MC
20.0%
y = 0.0058x + 0.0781 y = 0.0054x + 0.0767 y = 0.005x + 0.0722
R² = 0.8597
R² = 0.8797
R² = 0.9083
18.0%
16.0%
Oven‐Dry %MC
14.0%
12.0%
10.0%
8.0%
6.0%
4.0%
2.0%
0.0%
0.0
5.0
10.0
15.0
20.0
44
25.0
August 2009
Vesta FR Particleboard and corresponding Scanner SD %MC (3/4" Depth of Penetration/ Taken from Panel Face) fitted against Oven‐Dry %MC
20.0%
y = 0.007x + 0.069 y = 0.0067x + 0.0601
R² = 0.9373
R² = 0.947
18.0%
y = 0.0072x + 0.0735
R² = 0.9584
16.0%
14.0%
Oven‐Dry %MC
12.0%
10.0%
8.0%
6.0%
4.0%
2.0%
0.0%
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
45
18.0

Calibration of Hand-Held Moisture Meters

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