Specification - hand-operated sirens

IS 6026: Scope - Key Points & Specifications

Scope (Clause 1.1)
IS 6026 covers specifications for hand-operated sirens used for fire fighting and emergency services.

Important Specifications:

• Cover Requirements (Clause 4.2):

  • The cover must completely enclose the siren and floor-stand, including height adjusting bolts at maximum extension.
  • Waterproof cover stitches must be even and unbroken.

• Materials:

  • Aluminium and aluminium alloy ingots/castings for general engineering.
  • Carbon and carbon-manganese free-cutting steel.
  • Grey iron castings.
  • Ordinary quality structural steel.
  • Steel tubes for mechanical/general engineering.
  • Mild steel wire.
  • Cotton canvas for covers.

Key Formula (Clause 2.1.1 for twisting force):

[ \text{Twisting force} = MgR \quad \text{(Newton metres)} ]

Where:

• ( M ) = mass in kg
• ( g ) = acceleration due to gravity (9.81 m/s²)
• ( R ) = radius of pulley (m)

Acoustic Power Level Relation (Appendix A):

[ L_p = L_{ref} + L_{siren} - L_{ref-source} ]

Where:

• ( L_p ) = acoustic power level of siren (dB)
• ( L_{ref} ) = acoustic power level of reference source (dB)
• ( L_{siren} ) = sound pressure level due to siren (dB)
• ( L_{ref-source} ) = sound pressure level due to reference source (dB)

Units & Definitions (SI Units):

If you need detailed tables or further formulas, please specify the exact clause or aspect.

IS 6026 - Parts of the Siren (Clause 2.1 & Fig. 1)

The siren consists of:

• Siren body: Includes the disc and handle.
• Portable stand: Adjustable floor stand with height adjusting bolts.
• Handle with control: For warbling note (sliding disc controlled by handle).
• Bolts: Fixing bolt at siren base and height adjusting bolts on stand.
• Cover: Waterproof, fully covering siren and stand at max height (Clause 4.2).

Key Specifications:

• Materials per relevant IS codes:
  • Aluminium & aluminium alloys (engineering grade)
  • Carbon & carbon-manganese free-cutting steel
  • Grey iron castings
  • Structural steel (ordinary quality)
  • Steel tubes for mechanical use
  • Mild steel wire
  • Cotton canvas for cover

Acoustic Power Level Formula (Clause A.1.3):

[ L_{W(siren)} = L_{W(ref)} + L_{p(siren)} - L_{p(ref)} ] Where:

• (L_{W(siren)}) = Acoustic power level of siren (dB)
• (L_{W(ref)}) = Acoustic power level of reference source (dB)
• (L_{p(siren)}) = Sound pressure level due to siren (dB)
• (L_{p(ref)}) = Sound pressure level due to reference source (dB)

graph LR
  A[Siren Body] --> B[Disc]
  A --> C[Handle]
  D[Portable Stand] --> E[Height Adjusting Bolts]
  F[Fixing Bolt] --> A
  G[Waterproof Cover] --> A
  G --> D

For detailed maintenance and spare parts, refer to the illustrated instruction book (Clause 7.1).

IS 6026: Materials - Key Formulas & Specifications

1. Twisting Force (Torque) Formula

Given:

• M = mass in kg
• g = acceleration due to gravity (9.81 m/s²)
• R = radius of pulley (m)

Twisting Force, T (in N·m):
[ T = MgR ]

2. Angle of Twist Relation

• ( \tau ) = coefficient of rigidity (shear modulus) in N/m²
• ( e ) = angle of twist (radians)
• ( r ) = radius of rod (m)
• ( l ) = length of rod (m)

Torque and angle of twist relation:
[ T = \frac{\pi r^4 \tau e}{2l} ]

3. Material Specifications

• Gears: Carbon steel as per IS:4431-1978 or Cast Iron Grade FG 200 as per IS:210-1978
• Units: SI units are used throughout (N, m, Pa, etc.)

4. SI Units Reference

Summary Diagram of Torque and Twist

graph LR
A[Mass M] --> B[Force Mg]
B --> C[Pulley Radius R]
C --> D[Twisting Torque T = MgR]
E[Rod Radius r, Length l] --> F[Angle of Twist e]
D --> G[Torque T related to e by T = (π r⁴ τ e) / 2l]

Note: For detailed material properties, refer to IS 4431 and IS 210 standards.

IS 6026 - Shape and Dimensions Summary

Clause 4.1 & Fig. 1

• The shape and essential dimensions of the hand-operated siren and floor-stand are specified in Fig. 1 (all dimensions in millimeters).
• The cover must fully enclose the siren and floor-stand, including height adjusting bolts at maximum extension (Clause 4.2).

Key Specifications:

• Waterproof cover color: Olive green (IS:1424-1977, Variety No. 2).
• Material standards: Aluminium, steel, castings per relevant IS specifications (see context).

Important Formula (Clause 2.1.1 - Calibration):

For twisting force on a rod: [ \text{Twisting force} = MgR \quad \text{(Newton-meters)} ] Where:

• (M) = mass in pan (kg)
• (g) = acceleration due to gravity (m/s²)
• (R) = radius of pulley (m)

Rod twist relation: [ T = \frac{7 \pi r^4 e}{2 L} ] Where:

• (7) = coefficient of rigidity (N/m²)
• (r) = rod radius (m)
• (e) = angle of twist (radians)
• (L) = rod length (m)

Units:

• Force: Newton (N) = kg·m/s²
• Energy: Joule (J) = N·m
• Pressure/Stress: Pascal (Pa) = N/m²

Diagram (Conceptual Siren Cover and Stand)

graph TB
  A[Siren] --> B[Floor-Stand]
  B --> C[Height Adjusting Bolts]
  C --> D[Waterproof Cover (Olive Green)]
  D --> E[Complete Coverage at Max Height]

For exact dimensions, refer to Fig. 1 of IS 6026.

IS 6026 - Performance Requirements: Key Formulas & Specifications

1. Acoustic Power Level (Clause A.1.3)

The acoustic power level ( L_W ) of the siren under test (in dB) is calculated as:

[ L_W = L_{W,ref} + L_{p,siren} - L_{p,ref} ]

• ( L_{W,ref} ): Acoustic power level of reference source (dB)
• ( L_{p,siren} ): Sound pressure level due to siren (dB)
• ( L_{p,ref} ): Sound pressure level due to reference source (dB)

2. Twisting Force (Clause 2.1.1, Table B-2)

For calibration involving twisting rods:

[ \text{Twisting Force} = MgR \quad \text{(Newton-meters)} ]

Where:

• ( M ) = mass in pan (kg)
• ( g ) = acceleration due to gravity (9.81 m/s²)
• ( R ) = radius of pulley (m)

Rod twist relation:

[ T = \frac{G \pi r^4 e}{2L} ]

Where:

• ( G ) = coefficient of rigidity (N/m²)
• ( r ) = radius of rod (m)
• ( e ) = angle of twist (radians)
• ( L ) = length of rod (m)

3. Durability (Clause 4.2)

• Cover must fully enclose siren and floor-stand including height adjusting bolts at max extension.
• Waterproof cover stitches must be even and unbroken.

4. Units (SI Units as per IS 6026)

IS 6026: Workmanship, Finish, and Cover - Key Points

1. Workmanship (Clause 6.1)

• Forgings and castings must be sound, free from pits, blowholes, scales, cracks.
• No repairs or fillings that hide defects allowed.
• All burrs and sharp edges to be removed or rounded smoothly.

2. Finish and Cover (Clauses 3.4 & 4.2)

• Waterproof cover color: Olive green, conforming to IS 1424:1977 (Cotton canvas, 2nd revision).
• Cover must completely cover the siren and floor-stand, including height adjusting bolts at maximum extension.
• Stitches on the cover must be even and unbroken.

3. Torque Requirement (Clause 5.3)

• Torque to drive siren at 60 ± 2 rpm should not exceed 1.5 Nm (tested as per Appendix B).

Summary Table

flowchart TD
    A[Forgings & Castings] --> B[No defects, burrs removed]
    C[Waterproof Cover] --> D[Olive green, IS 1424]
    D --> E[Full coverage including bolts]
    E --> F[Even, unbroken stitches]
    G[Siren Operation] --> H[Torque ≤ 1.5 Nm at 60 rpm]

This ensures durability, smooth operation, and environmental protection per IS 6026.

IS 6026: Instructions for Use and Maintenance - Key Points

Instruction Book (Clause 7.1)

• Each siren unit must include an illustrated manual with:
  • Simple instructions for mounting the siren on the floor stand.
  • Guidelines for normal operation and upkeep, including lubrication.
  • An itemized, illustrated spare parts list with reference numbers for all wearing parts to ensure availability.

Lubrication (Clause 6.3)

• Lubrication points must be clearly marked with "oil" or "grease" near the nipples.

Cover Specifications (Clause 4.2)

• The cover should fully enclose the siren and floor stand at maximum height.
• Waterproof cover stitches must be even and unbroken.

Related Formula (Clause 2.1.1 - Calibration)

For twisting force on the rod:

[ \text{Twisting force} = MgR \quad \text{(Newton metres)} ]

Where:

• ( M ) = mass in pan (kg)
• ( g ) = acceleration due to gravity (9.81 m/s²)
• ( R ) = radius of pulley (m)

Lubrication Marking Example

flowchart LR
    A[Siren Unit] --> B[Lubrication Points]
    B --> C{Marking}
    C -->|Oil| D["Oil" painted near nipple]
    C -->|Grease| E["Grease" painted near nipple]

Summary: Provide a clear, illustrated manual with mounting, operation, lubrication, and spare parts info. Mark lubrication points visibly. Use the twisting force formula for calibration checks. Ensure protective covers meet clause 4.2 specs.

IS 6026: Marking Specifications Summary

Clause 8.1.1: ISI Certification Mark

• Sirens may be marked with the ISI Certification Mark.
• ISI Mark indicates compliance with the Indian Standard under strict inspection and quality control.
• Use of ISI Mark is governed by the Indian Standards Institution (Certification Marks) Act.
• License details for ISI Mark usage can be obtained from ISI.

Clause 6.3: Lubrication Points Marking

• Lubrication points must be clearly marked with "oil" or "grease" near the nipple points.

Key Points on Marking:

• ISI Mark: Assurance of quality and compliance.
• Lubrication Points: Clearly labeled for maintenance.
• Cover Marking: Not specified, but cover must fit as per Clause 4.2.

Additional Notes:

• Marking ensures traceability and proper maintenance.
• ISI Mark usage is a legal and quality assurance requirement.
• Clear markings on lubrication points prevent maintenance errors.

flowchart TD
    A[Sirens] --> B{Marking}
    B --> C[ISI Certification Mark]
    B --> D[Lubrication Points Marked "oil"/"grease"]
    C --> E[Compliance & Quality Assurance]
    D --> F[Maintenance Clarity]

For detailed licensing and marking conditions, contact the Indian Standards Institution.

IS 6026: Method for Measurement of Acoustic Power and Durability

A-1. Acoustic Power Measurement

The acoustic power level (Lw) of the siren under test is given by:

[ L_w = L_{w0} + L_{pm} - L_{p0} ]

Where:

Or, in terms of power (W):

[ 10 \log_{10} \frac{W}{W_0} = 10 \log_{10} \frac{W_0}{W_0} + 20 \log_{10} \frac{P_m}{P_0} - 20 \log_{10} \frac{P}{P_0} ]

Where:

• (W) = acoustic output power of siren (W)
• (W_0 = 10^{-12}) W (reference power)
• (P_m) = sound pressure level of siren (ref. 0.00002 N/m²)
• (P_0) = sound pressure level of reference source (ref. 0.00002 N/m²)

A-2. Durability Specification

• The mean sound pressure level must be ≥ 118 dB (ref. 0.00002 N/m²).
• Measurement environment: Semi-reverberant room of volume 127.5 m³ with reverberation time 2 seconds (or equivalent).

Summary Table

IS 6026 - Method of Measurement of Torque: Key Points

Experimental Setup (Clause B-1.1)

• A steel rod A is supported on two ball bearings B1, B2 fixed on stands S1, S2.
• One end connects to the siren; the other end has a handle H.
• A semi-circular disc D fixed near siren end with a spring-loaded pointer P at handle end.
• Torque causes rod twist → pointer deflects proportionally on disc.

Calibration (Clause B-2.1)

• Replace handle H with pulley of radius R.
• Apply torque by hanging weight M on string over pulley.
• Torque applied:
  [ \text{Torque} = MgR \quad \text{(Newton-meters)} ] where
  • ( M ) = mass (kg)
  • ( g ) = acceleration due to gravity (9.81 m/s²)
  • ( R ) = radius of pulley (m)

Relation between Torque and Twist (Clause B-2.1.1)

[ MgR = \frac{\pi G r^4}{2 L} \theta ] where:

• ( G ) = modulus of rigidity (N/m²)
• ( r ) = radius of rod (m)
• ( L ) = length of rod (m)
• ( \theta ) = angle of twist (radians)

Summary Table for Units

Visual Summary (Torque Measurement Setup)

graph LR
  A[Steel Rod] -- connected to --> S[Siren]
  A -- supported by --> B1[Ball Bearing 1]
  A -- supported by --> B2[Ball Bearing 2]
  A -- handle end --> H[Handle or Pulley]
  D[Semi-circular Disc] -- pointer --> P[Pointer]
  H -- rotation causes --> Twist[Twist in Rod]
  Twist -- causes --> PointerDeflection[Pointer Deflection on Disc]

This method allows direct measurement of torque by correlating pointer def