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D3180-15 – Standard Test Method Technical Guide
📐 Analytical Bases Defined in D3180
ASTM D3180-15 defines several key analytical bases used in coal and coke testing. These bases ensure consistent reporting of analytical data across the industry. The primary bases defined include:
- As-determined basis: Data from the analysis sample after conditioning to No. 60 (250-µm) sieve as per Practice D2013.
- As-received basis: Data calculated to the moisture condition of the sample upon arrival at the laboratory.
- Dry basis: Data calculated to a theoretical base of no moisture, using test methods D3173 or D7582.
- Dry, ash-free basis: Data calculated to a theoretical base of no moisture or ash, using test methods D3173, D3174, or D7582.
- Equilibrium moisture base: Data calculated to the moisture level established by Test Method D1412.
| 🟦 Base | 📏 Definition |
|---|---|
| As-determined | Analytical data from the analysis sample after conditioning to No. 60 (250-µm) sieve |
| As-received | Moisture condition of the sample as it arrived at the laboratory |
| Dry | Theoretical base with no moisture, using D3173 or D7582 |
| Dry, ash-free | Theoretical base with no moisture or ash, using D3173, D3174, or D7582 |
| Equilibrium moisture | Moisture level established by D1412 |
⚙️ Application of Conversion Formulas
The standard provides formulas for converting analytical data from the as-determined basis to other common bases. These conversions require moisture and ash values determined by referenced test methods. The formulas enable accurate expression of data for various applications in the coal and coke industry.
⚠️ Important: The conversion formulas assume the analysis sample has been prepared according to Practice D2013 and Test Method D3302. Proper preparation is critical for valid results.
The standard references multiple test methods for determining moisture and ash content, including D3173, D3174, and D7582. These methods provide the numerical values necessary for conversions.
📊 Industry Significance and Compliance
D3180-15 is widely used in the coal and coke industry for standardizing analytical reports. By following this practice, laboratories ensure that data is comparable across different test conditions. The standard also emphasizes the use of significant digits as per Practice E29 to maintain data integrity. This international standard was developed in accordance with WTO TBT principles.
✅ Tip: Always document the moisture basis when reporting coal and coke analyses to ensure proper interpretation of data.
❓ Frequently Asked Questions
🔍 What is the as-determined basis?
The as-determined basis refers to analytical data obtained from the analysis sample after conditioning and preparation to a No. 60 (250-µm) sieve in accordance with Practice D2013 and Test Method D3302. It represents the numerical values at the particular moisture level at the time of analysis.
💡 Why are different bases used?
Different bases allow analytical data to be expressed in various moisture conditions common in the coal and coke industry. This practice provides formulas for converting from the as-determined sample to bases such as dry, as-received, and equilibrium moisture, enabling consistent reporting.
© 2026 TNLab — This article is a technical interpretation for reference only. The original standard as published by ASTM International takes precedence.