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D347-04 – Standard Test Method Technical Guide
📐 Overview and Scope of D347-04
ASTM D347-04, originally approved in 1932 and last revised in 2004, provides standardized tables developed by the National Institute of Standards and Technology (NIST) for the wood‑preserving industry. These tables enable convenient conversion of creosote volumes and specific gravity observations to a standard temperature basis of 100 °F (37.8 °C) or 38 °C. The correction factors are derived from density determinations performed on a representative range of domestic coke‑oven tars and apply to three classes of materials: creosote, creosote‑coal tar solution (up to 50 % tar), and coal tar. Tables 1‑4 present parallel correction factors for both volume and specific gravity, facilitating accurate measurement and regulatory compliance in treatment plant operations.
💡 Tip: When using Tables 1 and 2, multiply the observed volume by the factor corresponding to the observed temperature to obtain the volume at 100 °F. For observed specific gravity, add the correction for temperatures above 100 °F and subtract it for temperatures below 100 °F.
⚙️ Volume and Specific Gravity Correction Methodology
The correction procedure depends on whether you are adjusting volume or specific gravity. For volume correction (Tables 1 and 2), the observed volume is multiplied by a temperature‑dependent factor. For example, 1 gal of creosote measured at 120 °F occupies 0.9921 gal at 100 °F. Therefore, 10 000 gal measured at 120 °F corresponds to 10 000 × 0.9921 = 9 921 gal at the standard temperature. Table 3 provides analogous factors for metric users, based on 1 °C intervals with the reference at 38 °C.
For specific gravity correction (Tables 1 and 2 for °F; Table 4 for °C), the observed value is adjusted by adding the tabulated correction for temperatures above the reference and subtracting it for temperatures below. Table 4 employs signed corrections (negative values below 38 °C), so the user adds the correction—positive or negative—to the observed specific gravity to obtain the corrected value.
⚠️ Important: The corrections in Tables 1–4 are based exclusively on coke‑oven tars and may not be valid for other tar types (e.g., water‑gas tars). Always verify that your material falls within the scope defined in Section 1.1 before applying these factors.
📊 Key Measured Properties and Example Data from Table 1
Table 1 below presents a representative excerpt of volume correction factors for the three material classes across a range of observed temperatures. The factor values decrease as temperature increases, reflecting thermal expansion of the liquid.
| 🟦 Observed Temp., °F | 📏 Creosote | 📐 Solution (≤50% Tar) | 🎯 Coal Tar |
|---|---|---|---|
| 220 | 0.9526 | 0.9542 | 0.9594 |
| 200 | 0.9605 | 0.9619 | 0.9663 |
| 180 | 0.9684 | 0.9696 | 0.9732 |
| 160 | 0.9763 | 0.9773 | 0.9800 |
| 140 | 0.9842 | 0.9850 | 0.9867 |
| 120 | 0.9921 | 0.9926 | 0.9934 |
| 100 | 1.0000 | 1.0000 | 1.0000 |
Note: At the reference temperature (100 °F) the factor is exactly 1.0000 for all materials. The rate of change of the factor with temperature is slightly larger for creosote than for coal tar, reflecting differences in thermal expansion coefficients.
Table 2 below shows the corresponding specific gravity corrections (to be added to the observed specific gravity for temperatures above 100 °F, subtracted for temperatures below). Values are expressed in units of specific gravity (dimensionless).
| 🟦 Observed Temp., °F | ⚡ Creosote | 📐 Solution (≤50% Tar) | 🎯 Coal Tar |
|---|---|---|---|
| 220 | +0.0242 | +0.0226 | +0.0178 |
| 180 | +0.0151 | +0.0140 | +0.0109 |
| 140 | +0.0073 | +0.0068 | +0.0053 |
| 100 | 0.0000 | 0.0000 | 0.0000 |
✅ Application Example: If a sample of creosote measures a specific gravity of 1.085 at 140 °F, the corrected specific gravity at 100 °F = 1.085 + 0.0073 = 1.0923. For metric users, Table 4 provides analogous signed corrections with 1 °C intervals referenced to 38 °C.
❓ Frequently Asked Questions
🔍 What materials are covered by D347‑04?
The standard applies to creosote, mixtures of creosote and coal tar containing up to 50 % tar (designated as “solution”), and coal tar derived from coke‑oven operations. Other tar types are not within scope.
💡 How do I convert a volume measured at 150 °F to 100 °F using Table 1?
Locate 150 °F in the table (interpolate between 140 and 160 °F if needed), read the corresponding factor for your material, and multiply the observed volume by that factor. The result is the equivalent volume at 100 °F.
⚡ I have a specific gravity measured at 38 °C. How do I correct it to 38 °C?
At the reference temperature (38 °C) the correction is zero—no adjustment is needed. If your measurement was taken at a different temperature, use Table 4 and add the signed correction (positive or negative) to the observed value.
📌 Are these tables adopted by any industry associations?
Yes. The tables have been formally adopted as standard by the American Wood Preservers’ Association and the American Railway Engineering Association, and were developed by a Joint Conference Committee representing these organizations along with ASTM.