AS ISO 7546:2021 Earth-moving machinery — Loader and front loading excavator buckets — Volumetric ratings.
1  Scope and field of application
1.1 This International Standard specifies a procedure for approximating the volume of typical materials contained in the bucket of front end loaders and excavators with front loading bucket. The volume ratings
are based on the inside dimensions of the bucket and representative volumes on top of the bucket.
1.2 The method employs the technique of dividing the complex shape of the material in the bucket into simple geometric forms to allow volume calculations of different bucket configurations.
1.3 The rating method is intended to provide a consistent means of comparing bucket capacities. It is not intended to define actual capacities that might be observed in any specific application.
2  References
ISO 7131, Earth-moving machinery — Loaders — Terminology. 1)
ISO 7135, Earth-moving machinery — Excavators — Terminology. 1)
3  Restrictions and limitations
3.1 The effect on volumes of local discontinuities such as bucket teeth, tooth adapters, and gussets shall be ignored.
3.2 Grated or slotted back sheets attached to the bucket to protect the machine or operator from material that might spill over the back of the bucket shall not be included in the capacity calculations.Solid extended back sheets providing the same function may be included in the capacity calculations only if they are an integral part of the bucket.
3.3 Only buckets with an X/Y ratio greater than 12 shall be considered by the rating method(s). (See figure 2.)
4  Definitions and symbols
4.1  bucket component
See figure 1 and ISO 7131 and 7135.
strike plane
Horizontal plane across the width of the bucket from the cutting edge to the back sheet.
(See clause 5 for different bucket shapes.)
struck volume
Volume which lies beneath the strike plane.
top volume
Volume of material, a 2:1 slope, which lies on top of the strike plane.
rated bucket volume
Rated bucket capacity.
This capacity is calculated by adding the struck and top volumes : V R = V S + V T
5  Volumetric ratings
5.1  Basic bucket
The back sheet does not extend beyond a transverse line connecting the rear corners of the side sheets and the cutting edge does not extend beyond a transverse line connecting the front corners of the side sheets.
5.1.1 The strike plane passes through a line along the top of the back sheet at the rear and a line along the top of the cutting edge at the front as shown in figure 3.
5.1.2 The volumetric capacity is calculated as shown in figure 3.AS ISO 7546 pdf download.