Non-coniferous logs

IS 7308 - Scope Summary

• Scope Definition: IS 7308 specifies requirements for certain materials or products (not detailed here), allowing purchaser options per Clauses 7.1 and 8.6.3 to suit their needs at order time.

• Key Clauses:

  • 7.1: Permits purchaser's option for selection.
  • 7.2: Measurements (details not provided).
  • 2: Normative references to other standards for compliance.

• Rounding Off: Final test or analysis values must be rounded per IS 2:1960, retaining the same significant figures as specified.

• Technical Committee & Amendments: Composition in Annex C; amendments tracked in a table (empty here).

• BIS Contact: Headquarters and regional offices listed for queries.

Important Notes:

• The standard allows flexibility in selection to suit purchaser requirements.
• Compliance verification follows IS 2 rounding rules.
• Refer to Annex C for committee details and latest amendments.
• For exact formulas, tables, or detailed specs, consult full IS 7308 document.

Reference: IS 2:1960 Rounding Rule (Summary)

If you need formulas or tables related to specific materials or tests under IS 7308, please specify the clause or product type.

IS 7308: Normative References - Key Points

• Normative references are other standards integral to IS 7308; they form part of the requirements by reference.
• Users should verify the latest editions of these referenced standards for compliance.
• The standard follows IS 2:1960 for rounding off numerical values.
• Relevant Indian Standards for logs (by end-use) include:

Additional Notes:

• The purchaser can select options per clauses 7.1 and 8.6.3.
• Final test/analysis values must be rounded as per IS 2 rules.
• BIS holds copyright; reproduction requires permission except for implementation details.

Summary Diagram: Normative Reference Flow

flowchart LR
    A[IS 7308 Standard] --> B[Referenced IS Standards]
    B --> C[IS 656 - Plywood Logs]
    B --> D[IS 1140 - Match Logs]
    B --> E[IS 5248 - Teak Logs]
    B --> F[IS 6342 - Rosewood Logs]
    B --> G[IS 6707 - Willow Logs]
    B --> H[IS 13240 - Walnut Logs]

This ensures harmonized application of related standards for logs in different uses.

IS 7308 - Definitions & Key Specifications Summary

• Reference Standards:

  • Definitions primarily from IS 707 (seasoned timber).
  • Timber species nomenclature from IS 1150.
  • Species list in Annex A & B of IS 7308.

• Measurement of Logs (Clause 7.2):

  • For logs other than 2.5 m length, permissible defect value P is adjusted by:

  [ P_{L} = P \times \frac{2.5}{L} ]

  where:

  • (L) = length of log in meters
  • (P) = permissible defect value for 2.5 m length

• General Requirements (Clause 6):

  • Timber quality, defects, and grading criteria align with IS 707 and timber technology glossary (second revision).

Quick Reference Table: Permissible Defect Adjustment

This ensures defect limits scale inversely with log length for consistent quality control.

flowchart LR
    A[Log Length L (m)] --> B{Is L = 2.5?}
    B -- Yes --> C[Permissible Defect = P]
    B -- No --> D[Permissible Defect = P × (2.5 / L)]

For detailed species and grading, refer to Annex A/B and IS 1150.

IS 7308: Classification and Grades of Non-Coniferous Logs

Classification (Clause 4.1)

Non-coniferous logs are classified into three grades based on cumulative permissible defects (see Clause 8):

Key Points:

• Grades depend on defect limits such as knots, shakes, rot, etc.
• Defect assessment is cumulative and quantified as per Clause 8.
• Logs are intended for conversion into sawn timber.

Related IS Standards for Specific Logs:

Notes:

• Final test values must be rounded as per IS 2:1960.
• Purchaser options allowed under Clauses 7.1 and 8.6.3 to select grades based on requirements.

Summary Table: Grades by Defect Limits

(Exact defect limits are detailed in Clause 8 of IS 7308.)

flowchart TD
    A[Non-Coniferous Logs] --> B{Grade Classification}
    B --> C[Grade I: Minimal Defects]
    B --> D[Grade II: Moderate Defects]
    B --> E[Grade III: Higher Defects]
    C --> F[Premium Timber]
    D --> G[General Use Timber]
    E --> H[Utility Timber]

This classification ensures logs meet quality requirements for their intended end-use.

IS 7308 - General Requirements (Clause 7.1)

Key Points:

• Purchaser's Option: Clause 7.1 allows the purchaser to select options suited to their requirements at order placement.

• Rounding Off: Final test or analysis values must be rounded per IS 2:1960 rules, retaining the same significant figures as specified values.

• Normative References: Definitions from IS 707 apply alongside this standard.

• Compliance: Use final observed/calculated values to check compliance with the standard.

Important Specifications Summary

Notes

• This clause sets procedural and administrative requirements rather than structural formulas.
• For technical parameters, refer to other clauses or related IS codes.

flowchart TD
    A[Order Placement] --> B{Purchaser's Option?}
    B -- Yes --> C[Select suitable options]
    B -- No --> D[Default specifications]
    C & D --> E[Testing & Analysis]
    E --> F[Round off values per IS 2:1960]
    F --> G[Check compliance with IS 7308]

For detailed technical formulas or tables, refer to specific clauses or related IS codes like IS 707.

IS 7308: Preparation of Logs — Key Specifications & Formulas

1. Minimum Dimensions of Logs (Clause 7.1)

2. Measurement Guidelines (Clause 7.2.1)

• Length: Shortest distance end-to-end, rounded down to nearest 0.05 m.
• Girth: Measured as mean girth in meters.

3. Volume Calculation (Clause 7.2.3)

Volume ( V ) in cubic meters is computed by the quarter-girth formula:

[ V = \frac{L \times G^2}{4 \times 10000} ]

Where:

• ( V ) = volume (m³)
• ( L ) = length (m)
• ( G ) = girth (cm)

Note: Convert girth from cm to m by dividing by 100 if using consistent units.

4. Reference Standards for Logs by End Use (Foreword Table)

• Logs for plywood: IS 656:1988
• Logs for matches: IS 1140:1988
• Teak logs for sliced veneers: IS 5248:1988
• Rosewood logs for sliced veneers: IS 6342:1987
• Willow logs for artificial limbs: IS 6707:1972
• Walnut logs for sliced veneers: IS 13240:1991

This ensures logs meet dimensional and volumetric standards for quality and suitability in processing.

IS 7308: Dimensions and Measurements of Logs

Key Specifications (Clause 7.1 & 6.2)

• Minimum log dimensions:
  • Length: 2.5 m
  • Mean girth: 100 cm
• Preparation:
  • Buttresses, branch remnants, large knots must be trimmed flush.
  • Ends must be saw-cut clean and perpendicular to the log axis.

Measurement Rules (Clause 7.2 & 7.2.1)

• Length: Measured as the shortest distance between ends, rounded down to nearest 0.05 m.
• Girth: Mean girth measured around the log.
• Volume Calculation: Based on length and girth (details in 7.2.2 & 7.2.3, typically using volume formulas for cylinders or frustums).

Volume Approximation Formula (for cylindrical logs):

[ V = \frac{G^2}{4\pi} \times L ]

Where:

• (V) = volume (m³)
• (G) = girth (m)
• (L) = length (m)

Summary Table: Minimum Dimensions

flowchart LR
    A[Log Preparation] --> B[Trim buttresses & knots flush]
    B --> C[Cut ends perpendicular]
    C --> D[Measure length (shortest distance)]
    D --> E[Round length down to 0.05 m]
    E --> F[Measure mean girth]
    F --> G[Calculate volume]

This ensures standardized measurement for quality control and volume estimation of logs per IS 7308.

Permissible Defects in Logs — IS 7308 Key Points

1. Volume Calculation (Clause 7.2.3):
Use the quarter-girth formula:
[ V = \frac{L \times G^2}{4} ]

• (V) = volume in m³ (rounded to 3 decimals)
• (L) = length of log in m
• (G) = girth in m

2. Permissible Defects (Clause 8.4.1 & 2.5):

• For every 2.5 m length from the butt end, max deviation allowed = 150 mm.
• Defect evaluation per IS 3364 (Part 1).

3. Maximum Defect Units Allowed per 2.5 m length:

4. For logs of length other than 2.5 m:
[ \text{Permissible Defect Units} = \frac{L}{2.5} \times P ]

• (L) = log length in m
• (P) = permissible defect units for 2.5 m length (from above table)

5. Timber Species:
Refer to Annex A & B of IS 7308 and nomenclature per IS 1150.

flowchart TD
    A[Log Length L] --> B{Is L = 2.5 m?}
    B -- Yes --> C[Max Defect Units = P (3,6,9 based on Grade)]
    B -- No --> D[Max Defect Units = (L/2.5) × P]
    C & D --> E[Check deviation ≤ 150 mm per 2.5 m segment]
    E --> F[Evaluate defects as per IS 3364 (Part 1)]

This ensures quality control by limiting defects proportionally to log length and grade.

IS 7308: Volume Calculation for Logs

Key Specifications:

• Minimum log length: 2.5 m
• Minimum mean girth: 100 cm (1.0 m)
• Length measurement: Shortest distance end-to-end, rounded down to nearest 0.05 m.

Volume Calculation (Clause 7.2.3):

The Quarter-Girth Formula is used:

[ \boxed{ V = \frac{G^2}{16} \times L } ]

Where:

• ( V ) = Volume in cubic metres (m³)
• ( G ) = Girth in metres (m)
• ( L ) = Length in metres (m)

Notes:

• Volume is rounded to three decimal places.
• Girth is measured around the log's cross-section.
• Length is measured as the shortest distance between ends.

Table 7.1: Minimum Dimensions of Logs

This method approximates the log volume assuming a roughly circular cross-section, suitable for timber volume estimation.

IS 7308 - Prophylactic Treatment of Timber Logs

Key Points from IS 7308 & Related Codes:

• Twist Allowance:
  Twist up to 10° slope is permissible; evaluation per IS 3364 (Part 1).

• End Coating:
  Ends of logs (minimum 150 mm length) must be coated as per IS 1141 to prevent moisture ingress and decay.

• Prophylactic Treatment:
  All debarked logs must be treated immediately after inspection according to IS 401 (Code of practice for preservation of timber).

IS 401 Highlights (Prophylactic Treatment):

• Purpose: Protect logs from fungal, insect attack during storage and before processing.
• Common Treatment Methods:
  • Chemical dipping or spraying with preservatives like copper-chrome-arsenic (CCA), creosote, or waterborne preservatives.
  • Duration: Treatment should be immediate and thorough for effective penetration.

Summary Table:

flowchart TD
    A[Inspection of Logs] --> B{Twist ≤ 10°?}
    B -- Yes --> C[Apply End Coating (≥150mm)]
    B -- No --> D[Evaluate per IS 3364]
    C --> E[Prophylactic Treatment (IS 401)]
    D --> E
    E --> F[Storage/Processing]

Note: Always refer to IS 401 for detailed chemical types, concentrations, and application methods for prophylactic treatment.

IS 7308: Marking and Certification Key Points

1. Marking Requirements (Clause 11.1)

Each log must be legibly and indelibly marked at a suitable place (preferably at the ends) with:

• Species abbreviation
• Supplier's identification mark and year of supply
• Length and mean girth of the log
• Grade indication:
  • Grade I: Square
  • Grade II: Triangle
  • Grade III: Circle

2. BIS Certification Mark (Clause 11.2)

• Each log may be marked with the BIS Standard Mark to indicate compliance.
• This mark certifies the product meets the Indian Standard requirements.

3. Rounding Off (Clause 7.1)

• Final test or analysis values should be rounded off as per IS 2:1960.
• Retain the same number of significant digits as specified in the standard.

Summary Table for Marking Symbols

Additional Notes:

• Marking ensures traceability and quality verification.
• BIS mark is optional but recommended for quality assurance.
• Follow IS 2:1960 for numerical rounding to maintain consistency.

flowchart LR
    A[Log] --> B[Mark Species Abbreviation]
    B --> C[Mark Supplier ID & Year]
    C --> D[Mark Length & Mean Girth]
    D --> E{Grade}
    E -->|Grade I| F[Square]
    E -->|Grade II| G[Triangle]
    E -->|Grade III| H[Circle]
    E --> I[Optional BIS Mark]

This concise marking system ensures clear identification and certification compliance per IS 7308.

IS 7308 Key Points on Annexes & Technical Committee Composition

• Annexes:

  • Annex C details the Technical Committee composition responsible for the standard's formulation.
  • Clauses 7.1 and 8.6.3 allow purchaser options for selection at order placement.
  • Rounding off test/analysis results follows IS 2:1960 rules, retaining the same significant figures as specified values.

• Technical Committee (Annex C):

  • Comprises experts from relevant fields (manufacturers, users, academia, government).
  • Ensures balanced representation for standard development.
  • Committee identified as CED 9 (5652) for this document.

• Additional Info:

  • BIS copyright protects the standard; reproduction requires permission.
  • BIS regional offices available for enquiry and support.

Summary Table

graph LR
A[IS 7308 Standard] --> B[Annex C: Technical Committee]
A --> C[Clauses 7.1 & 8.6.3: Purchaser Options]
A --> D[Rounding off per IS 2:1960]
B --> E[Experts: Manufacturers, Users, Govt, Academia]

For detailed committee member names and roles, refer to Annex C of IS 7308.