ASTM D4702-97
(Guide)Standard Guide for Inspecting Crosscut, Sweep-Arm, and Auger Mechanical Coal-Sampling Systems for Conformance with Current ASTM Standards
Standard Guide for Inspecting Crosscut, Sweep-Arm, and Auger Mechanical Coal-Sampling Systems for Conformance with Current ASTM Standards
SCOPE
1.1 This guide is applicable to crosscut, sweep-arm, and auger sampling systems.
1.1.1 Crosscut and Sweep-Arm Samplers -A crosscut sampler collects an increment as the sampler traverses a freely falling stream of coal, such as coal freely falling in a chute or freely falling from the head pulley of a conveyor. A sweep-arm sampler collects an increment as the sampler traverses a bed of coal on a moving conveyor belt. Both crosscut and sweep-arm sampling are designated Condition B (Full-Stream Cut) as defined in Section 6, Increment Collection Classification, of Test Methods D2234.
1.1.2 Auger Samplers -An auger sampler collects an increment of coal as the auger is inserted vertically into a stationary load of coal contained within a railcar, truck, or barge. Auger sampling is designated Condition D (Stationary Coal Sampling) as defined in Section 6, Increment Collection Classification, of Test Methods D2234.
1.2 Spacing of increments pertains to the kind of interval between increments. Intervals can be defined in quantitative terms, such as units of time or mass, or in terms of position over the lot.
1.2.1 Spacing of Increments for Crosscut and Sweep-Arm Samplers -Crosscut- and sweep-arm type mechanical sampling systems take increments based on time, either at fixed time intervals or at random times during a fixed time strata. Some crosscut samplers can take increments based on equal mass of coal sampled as determined by scales. The sections of this guide that pertain to crosscut and sweep-arm samplers describe procedures for only time-based sampling systems. This time-based inspection guideline will satisfy most criteria for mass-based or combination mass-based and time-based sampling systems. If there are items that are not covered, the inspector should refer to the manufacturer's literature.
1.2.2 Spacing of Increments for Auger Sampling -The spacing of increments collected by auger sampling systems is defined in terms of position over the lot.
1.3 It is essential that the inspector have the documentation listed in Section 2 of this guide when conducting an inspection.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.5 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For a specific hazard statement, see Section 5.
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Designation: D 4702 – 97
Standard Guide for
Inspecting Crosscut, Sweep-Arm, and Auger Mechanical
Coal-Sampling Systems for Conformance with Current
ASTM Standards
This standard is issued under the fixed designation D 4702; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 1.3 It is essential that the inspector have the documentation
listed in Section 2 of this guide when conducting an inspection.
1.1 This guide is applicable to crosscut, sweep-arm, and
1.4 The values stated in SI units are to be regarded as the
auger sampling systems.
standard. The values given in parentheses are for information
1.1.1 Crosscut and Sweep-Arm Samplers—A crosscut sam-
only.
pler collects an increment as the sampler traverses a freely
1.5 This standard does not purport to address all of the
falling stream of coal, such as coal freely falling in a chute or
safety concerns, if any, associated with its use. It is the
freely falling from the head pulley of a conveyor. A sweep-arm
responsibility of the user of this standard to establish appro-
sampler collects an increment as the sampler traverses a bed of
priate safety and health practices and determine the applica-
coal on a moving conveyor belt. Both crosscut and sweep-arm
bility of regulatory limitations prior to use. For a specific
sampling are designated Condition B (Full-Stream Cut) as
hazard statement, see Section 5.
defined in Increment Collection Classification of Practice
D 2234.
2. Referenced Documents
1.1.2 Auger Samplers—An auger sampler collects an incre-
2.1 ASTM Standards:
ment of coal as the auger is inserted vertically into a stationary
D 121 Terminology of Coal and Coke
load of coal contained within a railcar, truck, or barge. Auger
D 2013 Method of Preparing Coal Samples for Analysis
sampling is designated Condition D (Stationary Coal Sam-
D 2234 Practice for Collection of a Gross Sample of Coal
pling) as defined in Increment Collection Classification of
D 4749 Test Method for Performing the Sieve Analysis of
Practice D 2234.
Coal and Designating Coal Size
1.2 Spacing of increments pertains to the kind of interval
D 4916 Practice for Mechanical Auger Sampling
between increments. Intervals can be defined in quantitative
terms, such as units of time or mass, or in terms of position
3. Terminology
over the lot.
3.1 Definitions—Definitions applicable to this guide are
1.2.1 Spacing of Increments for Crosscut and Sweep-Arm
listed in Terminology D 121, Practices D 2234 and D 4916,
Samplers—Crosscut- and sweep-arm-type mechanical sam-
and Method D 2013.
pling systems take increments based on time, either at fixed
time intervals or at random times during a fixed time strata.
4. Significance and Use
Some crosscut samplers can take increments based on equal
4.1 This guide addresses the quality assurance criteria for
mass of coal sampled as determined by scales. The sections of
operation of a mechanical coal-sampling system in accordance
this guide that pertain to crosscut and sweep-arm samplers
with Practice D 2234, Method D 2013, and Practice 4916. This
describe procedures for only time-based sampling systems.
guide serves as a reference for inspecting mechanical coal-
This time-based inspection guideline will satisfy most criteria
sampling systems for conformance with applicable ASTM
for mass-based or combination mass-based and time-based
standards. It describes step-by-step procedures for such inspec-
sampling systems. If there are items that are not covered, the
tions, with specific ASTM references for each step.
inspector should refer to the manufacturer’s literature.
1.2.2 Spacing of Increments for Auger Sampling—The
5. Hazards
spacing of increments collected by auger sampling systems is
5.1 Precautions—In addition to other precautions, person-
defined in terms of position over the lot.
nel visiting facilities for observation of mechanical sampling
system performance should immediately upon arrival report to
the facility management to inform them of their presence and
This guide is under the jurisdiction of ASTM Committee D-5 on Coal and Coke
and is the direct responsibility of Subcommittee D05.23 on Sampling.
Current edition approved Sept. 10, 1997. Published May 1998. Originally
published as D 4702 – 87. Last previous edition D 4702 – 91. Annual Book of ASTM Standards, Vol 05.05.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 4702
the purpose of their visit. The inspector should ask for mine if any unloading, storage, or reclaiming procedures
drawings, specifications, and instructions on the applicable produce a cyclical pattern which could cause the increment
safety practices and regulations to be followed on the site. collection to get in phase with the sequence of coal variability.
Variations in the physical characteristics, such as particle-size
6. Assessing the Organization and Planning of Sampling
distribution, surface moisture, extraneous matter, and oversized
Operations
material, can become cyclical and even could be in phase with
6.1 It is recommended that inspection personnel meet with
the time-based increment collection. When such cyclical varia-
the appropriate personnel responsible for the mechanical sam-
tions occur in the coal stream, the source of the variations
pling system, on all visits, to discuss the organization and
should be investigated to determine the practicability of
planning of sampling operations. ASTM standards provide for
eliminating the variations. If there is no practical way to
the use of various options. Examples and references are given
eliminate the variations, then either the number of primary
in 6.1.1 and 6.1.2 as follows:
increments or the primary cutter velocity or both shall be
6.1.1 Crosscut and Sweep-Arm Samplers—The number of
varied.
primary increments for the gross sample collected by crosscut
NOTE 1—The number of primary increments should be varied by
or sweep-arm systems can be determined from the Sampling of
adjusting the time interval between primary cuts so that the period of
Coals Based on Size and Condition of Preparation or the
cyclic variation is not evenly divisible by the number of primary cuts per
Sampling of Coals Based on Known Sampling Characteristics
period or by using a method of random collection of primary increments.
of Practice D 2234.
8. General Observations of Auger Placement
6.1.2 Auger Sampling—Considerations for the number of
auger increments per lot and per vehicle are discussed in the 8.1 At a minimum, the inspector should examine the fol-
Consideration for Number of Auger Increments section (6.2) of lowing two aspects of the placement of the auger over the
Practice D 4916. surface of the coal being sampled: (1) human discretion in
6.2 Inspection personnel should refer to the sections of placement of the auger over the surface of the coal in the
Practice D 2234 and Practice D 4916 referenced in 6.2.1 and vehicle(s) and (2) the pattern of auger placement from vehicle
6.2.2 of this guide when assessing the conformance of the to vehicle for lots comprised of more than one vehicle load of
organization and planning of crosscut, sweep-arm, and auger coal.
sampling operations as follows: 8.1.1 Human Discretion—To the extent possible, human
6.2.1 Planning of Crosscut or Sweep-Arm Sampling discretion should be minimized with respect to auger place-
Operations—When assessing the conformance of the organi-
ment over the surface of the coal in the vehicle(s). The
zation and planning of sampling operations for a specific inspector should examine the placement of the auger over the
crosscut or sweep-arm mechanical sampling system, the in-
surface of the coal in at least one vehicle to determine that
spector should use Section 7, Organization and Planning of human discretion is minimized in positioning the auger.
Sampling Operations, of Practice D 2234 which covers the
8.1.2 Auger Placement Patterns—The inspector should re-
items that would be used in evaluating the sampling plan. Items fer to the Considerations for Auger Placement Patterns and
covered are: Precautions, Selection of Appropriate Sampling
Increment Collections section (6.4) of Practice D 4916 in
Procedure, Number and Weight of Increments, Increment regard to considerations for auger placement patterns and
Collection Method to be Used, Distribution of Increments,
increment collections.
Dimensions of Sampling Device, Movement of Sampling
9. Inspection of the Primary Sampler in Time-Based
Device, Preservation of Moisture, Contamination, Mechanical
Crosscut or Sweep-Arm Sampling Systems
System Features, Personnel, Criteria of Satisfactory Perfor-
9.1 It is suggested that the inspector start at the primary
mance, and Relative Location of Sampling and Weighing.
crosscut or sweep-arm sampler and follow through the system
6.2.2 Planning of Auger Sampling Operations—When as-
to the final online sample collection point. The inspection
sessing the conformance of the organization and planning of
should be made with and without coal running through the
sampling operations for a specific auger sampling system, the
system.
inspector should use Section 6, Organization and Planning of
9.2 The following items should be checked for the primary
Sampling Operations, of Practice D 4916, which covers the
sampler:
following items: Precautions, Consideration of Top Size, Con-
sideration for Number of Auger Increments, Considerations for 9.2.1 Check the crosscut or sweep-arm cutter opening to
determine that it complies with the Dimensions of Sampling
Auger Placement Patterns and Increment Collections, Preser-
vation of Moisture, Contamination, Mechanical System Fea- Device of Practice D 2234.
9.2.2 Sufficient inspection doors shall be available to ob-
tures, Personnel, Relative Location of Sampling and Weighing,
serve that the primary crosscut or sweep-arm cutter cuts the full
and Reduction and Mechanical Division of the Auger Incre-
stream of coal.
ments.
9.2.3 Observe, or if necessary, measure, the movement of
7. General Observations of Coal Stream Variability as
the primary crosscut or sweep-arm cutter to verify uniform
Related to Primary Increment Collection by Crosscut
speed while in the coal stream.
and Sweep-Arm Samplers
9.2.4 Determine the velocity of the crosscut or sweep-arm
7.1 The entire coal-handling system up to the crosscut or cutter by dividing the distance the cutter travels while in the
sweep-arm mechanical sampler should be examined to deter- coal stream by the time required for traveling that distance.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 4702
Make the velocity check for both directions if applicable. See ing, the inspector should check the following items:
the Movement of Sampling Device of Practice D 2234 for 11.4.1 A minimum of six secondary increments shall be
recommendations. These recommendations are not applicable collected from each uncrushed primary increment as specified
to sweep-arm cutters. in Practice D 2234 and 6.10.1.1 of Practice D 4916. The six or
9.2.5 For crosscut or sweep-arm systems, it should be more secondary increments should be equally spaced through-
determined that the proper number of primary increments are out the entire flow of the primary increment.
taken to satisfy the requirements of the Sampling of Coals 11.4.2 Each secondary increment must conform to the
Based on Size and Condition of Preparation or the Sampling of minimum increment weight specified in Table 2 of Practice
Coals Based on Known Sampling Characteristics of Practice D 2234 for nominal top size.
D 2234. It should be determined that the time interval between 11.4.3 Secondary cutter velocity must be uniform across the
primary cuts is correct to assure that the minimum number of entire coal stream and conform to the recommendations of the
increments are collected for the lot of coal being sampled Increment Collection Method to be Used and the Movement of
during the inspection based on maximum attainable feed rates. Sampling Device sections of Practice D 2234, and the Speed of
9.2.6 The inspector shall determine that the crosscut sample Sampling Device section (6.10.1.3) of Practice D 4916.
cutter is parked out of the stream of coal in the at rest position
NOTE 2—The use of a stopwatch may not provide sufficient accuracy
and that no coal is entering the cutter opening. There shall be
for short travel.
no holes in the baffle plate, dust doors, or seals that may cause
11.4.4 Cutter opening shall conform to the recommenda-
leaking of the sample into the primary sample hopper.
tions of the Dimensions of Sampling Device section of Practice
9.2.7 For crosscut and sweep-arm systems, the minimum
D 2234, and the Opening of Sampling Device section
weight of the primary sample increment shall be as specified in
(6.10.1.2) of Practice D 4916.
Table 2 of Practice D 2234.
11.4.5 The secondary cutter is out of the coal stream when
in the at rest position. See 9.2.6 of this guide for precautions
10. Inspection of Augers
against leakage.
10.1 The following items should be checked for the auger:
11.5 The sample crusher is fed from either the primary or
10.1.1 Check the auger assembly to determine that it com-
secondary sampler by a feeder. The requirements and criteria
plies with the Consideration of Top Size section (6.2) of
for the secondary feeder are the same as for the primary feeder
Practice D 4916.
as described in 11.3 of this guide.
10.1.2 Check the auger to determine that it extracts a
11.6 The sampling system can be designed to crush to an
vertical increment of coal extending from the surface to as
intermediate coal size, which in turn would be resampled
close as practicable to the bottom of the transport vehicle.
before it would be fed to a secondary sampler crusher or, as is
10.1.3 For auger sampling systems, it should be determined
done in many sampling systems, to crush to the final sample
that the proper number of primary (auger) increments are taken
size.
to satisfy the requirements of the Consideration for the Number
11.6.1 The sample crusher shall produce a product as
of Auger Increments section (6.3) of Practice D 4916.
required by design and shall be ample
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