Mini-Ligno DX Moisture Meter Calibration for SierraPine ... · PDF fileMini-Ligno DX Moisture Meter Calibration for SierraPine Encore FR ... and SierraPine Encore FR (SD) particleboard

2009 Mini-Ligno DX Moisture Meter Calibration for

SierraPine Encore FR (SD) Particleboard

Jonathan C. Gates

9Wood, Inc.

December 2009

Test Evaluation Report

[MINI‐LIGNO DX MOISTURE METER CALIBRATION FOR SIERRAPINE ENCORE FR (SD) PARTICLEBOARD]

December 2009

9Wood, Inc. | 0BAbstract: ii

Abstract: This report analyzes the response of an Electrical Moisture Meter when tested on total

of 90 samples of SierraPine Encore Fire Retardant (FR) Sustainable Design (SD) particleboard and Flakeboard Standard (non-FR) particleboard. 15 sample boards of SierraPine Encore FR (SD) particleboard were conditioned in one of five conditioning chambers of various temperatures and relative humidity (ASTM Standard Chamber, a Hot/Dry Chamber, a Hot/Wet Chamber, a Cold Chamber and “Inside” in an air conditioned environment). In addition to the 75 samples of SierraPine Encore FR (SD) particleboard, 15 samples of Flakeboard Standard (non-FR) particleboard were also conditioned “Inside” in an air conditioned environment. Moisture Content (MC) measurements were taken from the veneer on the non-Decorative side of each sample board with a Mini-Ligno DX moisture meter while on “Setting 3” with the short pins installed. Next, calibration of these readings were done using an ASTM D 4442 Oven-Dry method (method A) to determine the linear relationship between the two MC methods. A correction equation and an acclimation/equilibrium (EMC) chart were then created from the results. This EMC chart and correction equation will help in determining a fully acclimated SierraPine Encore FR (SD) particleboard panel for installation.

Note: This test is a continuation of “Calibration of Hand-Held Moisture Meters (Resistance/Capacitance) when used with 9Wood’s Particleboard Products”.

[MINI]

‐LIGNO DX MOISTURE METER CALIBRATION FOR SIERRAPINE ENCORE FR (SD) PARTICLEBOARD

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9Wood, Inc. | 0BAbstract: iii

Table of Contents:

Abstract: ....................................................................................................................................ii

Introduction: ............................................................................................................................. 1

Literature Review: .................................................................................................................... 1

Materials and Methodology: .................................................................................................... 2

Figure 1: Mini-Ligno DX Moisture Meter .................................................................................................... 3 Figure 2: Oven Used in Oven-Dry Method ................................................................................................ 3 Figure 3: Dimensions of Sample Board ..................................................................................................... 3 Table 1: Each particleboard type and its corresponding conditioning chamber. .................................... 4 Figure 4: Depiction of Mini-Ligno DX moisture meter and its placement on the panel. ............................ 4 Table 2: Sample board weights during the process of conditioning. ....................................................... 5 Equation 1: Formula used to calculate Oven-Dry MC. .............................................................................. 6 Figure 5: Picture of Mini-Ligno DX as it was applied to the tested panel. ................................................. 6 Figure 6: Picture of device used to weigh samples. ................................................................................. 6 Table 3: Table 3-4 from Wood Handbook that was used to extrapolate data in equilibrium/ acclimation chart. ......................................................................................................................................................... 7

Results and Discussion: .......................................................................................................... 7

Table 3: Comparison of average Oven-Dry %MC between Flakeboard Standard (non-FR) particleboard and SierraPine Encore FR (SD) particleboard after conditioning in each chamber. ................................. 7 Figure 7: Graph that depicts the Mini-Ligno DX “Meter Reading” fitted against each panel’s “Oven-Dry” percent moisture content. ......................................................................................................................... 8 Table 4: Correction Chart for the Mini-Ligno DX (Short Pin / Setting 3 / Taken from non-Decorative face veneer) when tested on SierraPine Encore FR (SD) particleboard. .......................................................... 8 Equation 2: Meter correction equation used to calculate actual %MC in SierraPine Encore FR (SD) particleboard with a face and back veneer while using the Mini-Ligno DX (Short Pin / Setting 3 / Taken from non-Decorative veneer). .................................................................................................................... 8 Table 5: Acclimation/Equilibrium chart for SierraPine Encore FR (SD) particleboard when using a Mini-Ligno DX (Short Pin / Setting 3 / Taken from non-Decorative veneer) moisture meter. ............................. 9 Figure 8: Acclimation/Equilibrium graph for SierraPine Encore FR (SD) particleboard when using a Mini-Lingo DX (Short Pin / Setting 3 / Taken from non-Decorative veneer) moisture meter. ........................... 10

Conclusion: ............................................................................................................................ 11

Literature Cited: ..................................................................................................................... 12

Appendices:............................................................................................................................ 13

Appendix I: Mini-Ligno DX (Short Pin / Setting 3 / Taken from non-Decorative veneer) Test Data ....... 14 Appendix II: Oven-Dry Moisture Contents .............................................................................................. 16 Appendix III: Comparison between “Meter Reading” and “Oven-Dry” moisture content ...................... 18


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9Wood, Inc. | 1BIntroduction: 1

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 an Electrical method moisture meter (resistance type) was tested against the Oven-Dry method on both SierraPine Encore FR (SD) Particleboard (a fire retardant design) and Flakeboard Standard (non-FR) Particleboard with a face and back veneer. The purpose of this project is to create acclimation/equilibrium (EMC) chart for SierraPine Encore FR (SD) particleboard (with a face and back veneer) while using a Mini-Ligno DX moisture meter. The test is also designed to create a correction equation for determining actual percent moisture content (MC) in SierraPine Encore FR (SD) particleboard by examining the difference in measurable MC between Flakeboard Standard (non-FR) Particleboard and SierraPine Encore FR (SD) particleboard.

Literature Review: In accordance to building codes and various standards, SierraPine Encore FR (SD) 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 SierraPine Encore FR (SD) particleboard is extremely


December 2009

9Wood, Inc. | 3BMaterials and Methodology: 2

volatile 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 tremendously important to calibrate the moisture meters to a given product as well as create an acclimation/equilibrium (EMC) 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 (EMC) chart) and actual meter reading become relatively equivalent.

Materials and Methodology: 1. Scope:

1.1. Calibrate the Lignomat Mini-Ligno DX (Short Pins installed / on Setting 3 / taken from the non-decorative veneer) moisture meter using the oven dry method established in ASTM D 4442 (method A) and ASTM D 4933.

1.1.1. Create acclimation/equilibrium (EMC) chart with the Relative Humidity (RH) and temperature from each conditioning chamber. Assumptions are to be drawn from the Wood Handbooks EMC chart (Table 3-4).

1.2. Create correction equation from the linear correlation between the Mini-Ligno DX moisture meter and the Oven-Dry MC of SierraPine Encore FR (SD) particleboard as well as the relationship between Oven-Dry MC of SierraPine Encore FR (SD) particleboard and Flakeboard Standard (non-FR) particleboard.

2. Referenced Documents: 2.1. 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. 3. Summary of Test Method:

3.1. 75 samples (15 in each room) of SierraPine Encore FR (SD) particleboard were conditioned in an ASTM Standard Chamber, a Hot/Dry Chamber, a Hot/Wet Chamber, a Cold Chamber, and “Inside” in a well air conditioned room. 15 samples of Flakeboard Standard (non-FR) particleboard were conditioned “Inside” in a well air conditioned room. MC measurements from the non-decorative veneer of each sample board were taken with a Mini-Ligno DX moisture meter while on “Setting 3” with the short pins installed. Next, calibration of these readings were done using an ASTM D 4442 Oven-Dry method (method A) to determine the linear relationship between the two MC methods. A correction equation and an acclimation/equilibrium (EMC) chart were then created from the results.

4. Significance and Use: 4.1. Refer to ASTM D 4442, D 4444, and D 4933.


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5. Apparatus: 5.1. Lignomat Mini-Ligno DX Moisture Meter (refer to Figure 1). 5.2. Refer to ASTM D 4442 & D 4933 for apparatus required for Oven-Dry Method (also

shown in Figure 2).

6. Test Materials:

6.1. Wood: 6.1.1. 75 prisms were made from SierraPine Encore FR (SD) particleboard with a face

and back veneer. 6.1.2. 15 prisms were made from Flakeboard Standard (non-FR) particleboard with a

face and back veneer. 6.2. Sample Size:

6.2.1. The specimens were made 4” (101.2mm) in width x 6” (152.4mm) in length x 3/4" (19mm) in thickness (Figure 3).

7. Sampling:

7.1. Constants: 7.1.1. 3/4" particleboard with face and back wood veneers. 7.1.2. Direction of veneer grain in relation to the direction of the moisture meter’s pins

(parallel correlation) 7.1.3. Tested veneer (Plain Sliced Maple) 7.1.4. Placement of moisture meter pins on veneer (Figure 4).

7.2. Variables: 7.2.1. Particleboard: (SierraPine Encore FR (SD) and Flakeboard Standard (non-FR)). 7.2.2. Conditioning: (ASTM, Hot/Dry, Hot/Wet, Cold, Inside/Air Conditioned).

6”

4”

¾”

Grain Direction

Figure 3: Dimensions of Sample Board

Figure 1: Oven Used in Oven‐Dry MethodFigure 2: Mini‐Ligno DX Moisture Meter


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7.3. 15 replications for each variable/combination was performed on the SierraPine Encore FR (SD) particleboard

7.4. 15 samples of the Standard particleboard were conditioned “Inside” in a well air conditioned room only.

8. Testing of Specimen: 8.1. A total of 3 readings (A,B,C) from the Mini-Ligno DX moisture meter with the short pins

installed while on “Setting 3” were taken from the non-decorative veneer (Figure 4).

8.2. The position of the Moisture Meter was strategically placed by following a simple pattern on the samples non-decorative veneer (Figure 4).

9. Conditioning: 9.1. The SierraPine Encore FR (SD) particleboard panels were conditioned in an ASTM

Chamber, Hot/Dry Chamber, Hot/Wet Chamber, Cold Chamber, and “Inside” in an air conditioned environment. The Flakeboard Standard (non-FR) panels were conditioned “Inside” only.

Particleboard type Conditioning ChamberTemperature Relative Humidity

(°C/°F) (%)

Encore ASTM 20/68 65

Encore Hot/Dry 30/86 20

Encore Hot/Wet 30/86 90

Encore Cold 5/41 80

Encore/Standard Inside/Air Conditioning 22/71 40

Table 1: Each particleboard type and its corresponding conditioning chamber.

9.2. Samples were left to acclimate until a steady weight was reached.

Grain Direction

Setting 3

Mini‐Lingo DX Placement

Figure 4: Depiction of Mini‐Ligno DX moisture meter and its placement on the panel.

B

A

C


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Sample Board Weight (grams) in Conditioning

Condition Board # Date

25‐Sep 26‐Sep 27‐Sep 28‐Sep 29‐Sep 30‐Sep 1‐Oct 2‐Oct 3‐Oct

ASTM

28 224.60 ‐ ‐ 224.45 224.36 224.40 224.44 224.42 224.40

29 227.74 ‐ ‐ 227.36 227.31 227.29 227.28 227.22 227.21

30 240.25 ‐ ‐ 239.08 238.91 238.76 238.66 238.57 238.49

Hot/Dry

58 245.53 ‐ ‐ 238.68 238.14 237.55 237.23 236.88 236.56

59 226.41 ‐ ‐ 219.76 219.32 218.82 218.58 218.25 218.03

60 236.35 ‐ ‐ 228.54 227.95 227.28 226.91 226.51 226.18

Hot/Wet

73 225.40 ‐ ‐ 228.55 228.83 229.14 229.41 229.66 229.81

74 223.64 ‐ ‐ 226.30 226.54 226.79 226.98 227.19 227.31

75 227.93 ‐ ‐ 231.13 231.29 231.82 232.07 232.30 232.41

Cold

43 234.82 ‐ ‐ 236.84 237.09 237.34 237.56 237.78 237.87

44 229.44 ‐ ‐ 231.38 231.60 231.88 232.13 232.35 232.48

45 230.51 ‐ ‐ 232.64 232.93 233.19 233.46 233.63 233.77

Inside

13 239.76 ‐ ‐ 238.08 237.88 237.59 237.63 237.69 237.19

14 236.27 ‐ ‐ 234.50 234.33 233.97 233.94 234.06 233.50

15 239.99 ‐ ‐ 238.75 238.54 238.29 238.32 238.39 237.93

Table 2: Sample board weights during the process of conditioning. 1. Procedure

1.1. Various SierraPine Encore FR (SD) particleboard and Flakeboard Standard (non-FR) particleboard panels were obtained from 9Wood’s manufacturing facility and cut into designated dimensions (refer to Figure 3).

1.2. Sample boards were labeled with a number (for reference) and their particleboard core.

1.3. 15 sample boards of the SierraPine Encore FR (SD) particleboard were then placed in one of the five conditioning rooms to acclimate until stable weights were reached. In addition, 15 samples of Flakeboard Standard (non-FR) particleboard were conditioned “Inside” in an air conditioned environment only (Table 1, 2 & 3).

1.4. Once acclimation was reached, the boards were transferred to plastic bags to prevent moisture gain/loss.

1.5. One by one, boards were removed for the bag, weighed, tested with the Mini-Ligno DX moisture meter (Figure 5) and then immediately placed back into another bag.


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1.6. Once all boards were tested, they were weighed and then placed into the oven to dry for their Oven-Dry moisture content (Figure 6).

1.6.1. The sample boards were left to dry for approximately 24 hours. Moisture content was determined using the Ov od (Equation 1). en-Dry meth

%WetWeight –Oven DryWeight

Oven Dry Weight

100

Equation 1: Formula used to calculate Oven-Dry MC.

1.7. The data was then analyzed to find the difference between Flakeboard Standard (non-FR) particleboard and SierraPine Encore FR (SD) particleboard. (Standard particleboard results were collected from the test Calibration of Hand-Held Moisture Meters (Resistance/Capacitance) when used with 9Wood’s Particleboard Products).

1.8. The data set from the Mini-Ligno DX moisture meter was graphed and a regression line fitted to the data points. From here, a correlation equation was determined.

1.9. An acclimation/equilibrium (EMC) chart was then created with the relative humidity (RH) and temperature from each conditioning chamber. Assumptions were drawn from the Wood Handbooks EMC chart (refer to Table 3).

1.10. A correction equation was created from the linear correlation between the Mini-Ligno DX moisture meter and the Oven-Dry MC of SierraPine Encore FR (SD) particleboard as well as the relationship between Oven-Dry MC of SierraPine Encore FR (SD) particleboard and Flakeboard Standard (non-FR) particleboard.

Figure 6: Picture of device used to weigh samples.

Figure 5: Picture of Mini‐Ligno DX as it was applied to the tested panel.


December 2009

9Wood, Inc. | 4BResults and Discussion: 7

Table 3: Table 3-4 from Wood Handbook that was used to extrapolate data in equilibrium/

acclimation chart.

1.11. Conclusions were drawn from results.

Results and Discussion: There was a common difference between Standard (non-FR) Flakeboard particleboard

and SierraPine Encore FR (SD) particleboard. On average, SierraPine Encore FR (SD) particleboard had an apparent 0.9% higher Oven-Dry MC over Standard Particleboard.

Average "Oven‐Dry" Moisture Content for Each Conditioning Chamber and Particleboard Type

Particleboard Type Conditioning Chamber

ASTM Hot/Dry Hot/Wet Cold InsideStandard (non‐FR) 9.5% 6.1% 12.8% 11.3% 7.5%

Encore (FR) 10.7% 6.4% 13.1% 12.9% 8.6%

Range 1.2% 0.3% 0.3% 1.7% 1.1% Table 3: Comparison of average Oven-Dry %MC between Flakeboard Standard (non-FR)

particleboard and SierraPine Encore FR (SD) particleboard after conditioning in each chamber. The Mini-Ligno DX presented signs of accuracy, precision, and reproducibility. As

shown in Figure 7, there was an average correlation of 96% between the panel’s “Meter Reading” and the “Oven-Dry” moisture content. (Note: complete set of data tables are shown in Appendix I)


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Figure 7: Graph that depicts the Mini-Ligno DX “Meter Reading” fitted against each panel’s “Oven-

Dry” percent moisture content. A correction chart and equation was created to find the actual %MC was created by

taking the linear regression of the Mini-Ligno DX (Short Pin/ Setting 3/ taken from the non-Decorative veneer) and the relationship between Flakeboard Standard (non-FR) particleboard and SierraPine Encore FR (SD) particleboard (Table 5 & Equation 2).

Meter Reading 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Actual %MC 4.7 5.0 5.3 5.7 6.0 6.3 6.7 7.0 7.3 7.7 8.0 8.3 8.7 9.0 9.3 9.6 10.0

Table 4: Correction Chart for the Mini-Ligno DX (Short Pin / Setting 3 / Taken from non-Decorative face veneer) when tested on SierraPine Encore FR (SD) particleboard.

Equation 2: Meter correction equation used to calculate actual %MC in SierraPine Encore FR (SD) particleboard with a face and back veneer while using the Mini-Ligno DX (Short Pin / Setting 3 /

Taken from non-Decorative veneer).

Encore OD %MC = 0.0036(Meter Reading) + 0.0374R² = 0.9636

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0

Encore Oven‐Dry %MC

Meter Reading

Mini‐Ligno DX (Short Pin) Setting 3 Linear (Mini‐Ligno DX (Short Pin) Setting 3)

jgates

Text Box

Actual %MC =0.9205[0.0036(Meter Reading)+0.0374]-0.0009


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The previous formula and table will only be helpful if the installer/user desires the true MC of the SierraPine Encore FR (SD) particleboard. However, since the purpose of this test was to create a process of determining a fully acclimated SierraPine Encore FR (SD) particleboard panel, the actual MC is unneeded. All that is necessary is a highly precise moisture meter with an acclimation/equilibrium (EMC) chart adjusted to the reading from the Meter (refer to Table 6 and Figure 8). This set of equipment assures the installer that the panels are fully acclimated to their environment when a stable “Meter Reading” close to the acclimation/equilibrium chart’s value is met.

Temperature

Moisture Content (%) at various relative humidity values

(°F) 20% 40% 65% 80% 90%

40 8.6 13.0 19.3 23.8 28.0

50 8.6 13.0 19.3 23.7 27.9

60 8.6 12.9 19.1 23.5 27.7

70 8.5 12.8 19.0 23.3 27.5

80 8.4 12.7 18.7 23.0 27.2

90 8.3 12.5 18.5 22.7 26.8

100 8.2 12.3 18.2 22.4 26.5

Table 5: Acclimation/Equilibrium chart for SierraPine Encore FR (SD) particleboard when using a Mini-Ligno DX (Short Pin / Setting 3 / Taken from non-Decorative veneer) moisture meter.


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9Wood, Inc. | 10

Figure 8: Acclimation/Equilibrium graph for SierraPine Encore FR (SD) particleboard when using a Mini-Lingo DX (Short Pin / Setting 3 / Taken from non-Decorative veneer) moisture meter.

0.0

5.0

10.0

15.0

20.0

25.0

30.0

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Mini‐Ligno

DX Meter Reading

Relative Humidity

40 Deg. F 70 Deg. F 100 Deg. F


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9Wood, Inc. | 5BConclusion: 11

Conclusion:

This study demonstrates that the Mini-Ligno DX (Short Pin / Setting 3 / Taken from non-Decorative veneer) moisture meter is a great tool for estimating the MC of laminated SierraPine Encore FR (SD) particleboard. With the correct procedure, panel acclimation can be easily predicted with the Mini-Ligno DX moisture meter. To obtain desirable results when measuring panel equilibrium moisture content (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).

2. Measure and record the relative humidity and temperature of the room. 3. Use the acclimation/equilibrium (EMC) chart or graph to estimate the target Mini-Ligno

DX meter reading for the given temperature and relative humidity. 4. Three readings from the back of the panel (non decorative side) are to be averaged

from the Mini-Ligno DX moisture meter while on “Setting 3” with the short pins installed. 5. 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.

6. 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.


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9Wood, Inc. | 6BLiterature Cited: 12

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.


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9Wood, Inc. | 7BAppendices: 13

9WOOD, INC.

Appendices: Copy of Test Data and Graphs

Test Evaluation Report

Jonathan C. Gates

August, 2009


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Appendix I: Mini-Ligno DX (Short Pin / Setting 3 / Taken from non-Decorative veneer) Test Data


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Appendix II: Oven-Dry Moisture Contents


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Appendix III: Comparison between “Meter Reading” and “Oven-Dry” moisture content

[MINI]

‐LIGNO DX MOISTURE METER CALIBRATION FOR SIERRAPINE ENCORE FR (SD) PARTICLEBOARD

December 2009

9Wood, Inc. | 7BAppendices:

19