ASTM D4916-97

Standard Practice for Mechanical Auger Sampling

SCOPE
1.1 This practice describes procedures for the collection of an increment, partial sample, or gross sample of material using mechanical augers. Reduction and division of the material by mechanical equipment at the auger is also covered. Further manual or mechanical reduction or division of the material elsewhere shall be performed in accordance with Method D2013.  
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 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.

General Information

• Status: Historical
• Publication Date: 31-Dec-1990
• ICS: 73.100.30 - Equipment for drilling and mine excavation
• Technical Committee: D05 - Coal and Coke
• Drafting Committee: D05.23 - Sampling

Relations

• Referred By: ASTM D6883-17 - Standard Practice for Manual Sampling of Stationary Coal from Railroad Cars, Barges, Trucks, or Stockpiles
• Effective Date: 01-Jan-1991
• Referred By: ASTM D7430/D7430M-22 - Standard Practice for Mechanical Sampling of Coal
• Effective Date: 01-Jan-1991
• Referred By: ASTM D7204-15 - Standard Practice for Sampling Waste Streams on Conveyors
• Effective Date: 01-Jan-1991

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 4916 – 97
Standard Practice for
Mechanical Auger Sampling
This standard is issued under the fixed designation D 4916; 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 is the observed and true sulfur content of a coal consignment.
This measurement is affected by chance errors as well as by
1.1 This practice describes procedures for the collection of
bias.
an increment, partial sample, or gross sample of material using
3.1.2 auger increment—the retained portion of one extrac-
mechanical augers. Reduction and division of the material by
tion operation of the auger.
mechanical equipment at the auger is also covered. Further
3.1.3 bias (systematic error)—an error that is consistently
manual or mechanical reduction or division of the material
negative or consistently positive. The mean of errors resulting
elsewhere shall be performed in accordance with Method
from a series of observations that does not tend towards zero.
D 2013.
3.1.4 chance error—error that has equal probability of
1.2 The values stated in SI units are to be regarded as the
being positive or negative. The mean of the chance errors
standard. The values given in parentheses are for information
resulting from a series of observations tends toward zero as the
only.
number of observations approaches infinity.
1.3 This standard does not purport to address all of the
3.1.5 consignment—a discrete amount of coal, such as a
safety concerns, if any, associated with its use. It is the
shipment, a car load, a unit train, or a day’s production. A
responsibility of the user of this standard to establish appro-
consignment may include more than one lot of coal and may
priate safety and health practices and determine the applica-
correspond to a specific period of time, such as a sampling
bility of regulatory limitations prior to use.
period or a billing period.
2. Referenced Documents 3.1.6 error—difference of an observation or a group of
observations from the best obtainable estimate of the true
2.1 ASTM Standards:
value.
D 431 Method for Designating the Size of Coal from Its
3.1.7 gross sample—a sample representing one lot of coal
Sieve Analysis
and composed of a number of increments on which neither
D 2013 Method of Preparing Coal Samples for Analysis
reduction nor division has been performed.
D 2234 Practice for Collection of a Gross Sample of Coal
3.1.8 increment—a small portion of the lot collected by one
E 177 Practice for Use of the Terms Precision and Bias in
operation of a sampling device and normally combined with
ASTM Test Methods
other increments from the lot to make a gross sample.
3. Terminology
3.1.9 lot—a quantity of coal to be represented by the gross
sample.
3.1 Definitions:
3.1.10 precision—a term used to indicate the capability of a
3.1.1 accuracy:
person, an instrument, or a method to obtain reproducible
3.1.1.1 generally, a term used to indicate the reliability of a
results; specifically, a measure of the chance error as expressed
sample, a measurement, or an observation.
by the variance, standard error, or a multiple of the standard
3.1.1.2 specifically, a measure of closeness of agreement
error (see Practice E 177).
between an experimental result and the true value. An example
3.1.11 representative sample—a sample collected in such a
manner that every particle in the lot to be sampled is equally
1 represented in the gross or divided sample.
This practice is under the jurisdiction of ASTM Committee D-5 on Coal and
3.1.12 sample—a quantity of material taken from a larger
Coke and is the direct responsibility of Subcommittee D05.23 on Coal Sampling.
Current edition approved Nov. 10, 1997. Published May 1998. Originally
quantity for the purpose of estimating the properties or
published as D 4916 – 89. Last previous edition D 4916 – 91.
composition of the larger quantity.
Discontinued; see 1988 Annual Book of ASTM Standards, Vol 05.05.
3.1.13 sample division—a process whereby a sample is
Annual Book of ASTM Standards, Vol 05.05.
Annual Book of ASTM Standards, Vol 14.02. reduced in weight without change in particle size.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 4916
3.1.14 significant loss—any loss that introduces a bias in allow passage of the largest top size in the lot of coal to be
final results that is of appreciable economic importance to the sampled. If the top size of coal makes the auger size imprac-
concerned parties. tical, the auger should be designed to cut through or break up
3.1.15 size consist—the particle size distribution of a coal. the lumps of coal.
3.1.16 spacing of increments—the spacing of increments
6.3 Consideration for Number of Auger Increments—The
pertains to the kind of intervals between increments. Two
number of increments required should be based on the lot size
spacing methods are recognized: systematic and random.
and degree of material preparation. For purposes of this
Systematic spacing is usually preferable.
practice, the degree of preparation is divided into two catego-
3.1.16.1 systematic spacing 1—in which the movements of
ries, that is, raw and mechanically cleaned. The lot size may be
individual increment collection are spaced evenly in time or in
determined by factors such as prior contractual agreements,
position over the lot.
operational restrictions, coal storage capabilities, and coal
3.1.16.2 random spacing 2—in which the increments are
transportation methods such as rail car, truck, or barge.
spaced at random in time or in position over the lot.
Determine the number of increments required to represent the
3.1.17 subsample—a sample taken from another sample.
lot by the following formula:
3.1.18 top size—the opening of the smallest screen in the
N 5 N ~a/908 Mg or 1000 tons!
=
2 1
series upon which is retained less than 5 % of the sample (see
Method D 431).
where:
3.1.19 unbiased sample (representative sample)—a sample
N = 15 for clean coal and 35 for raw coal,
free of bias.
N = number of increments required, and
a = lot size, Mg (tons).
4. Summary of Practice
6.3.1 Determine recommendations for the number of auger
4.1 A sample of coal is extracted from a stationary load
increments per vehicle by the following formula:
contained within a railcar(s), truck(s), or barge(s) by inserting
N 5 N 3 b/a
3 2
an auger into the vehicle in a vertical manner to extract a
columnar sample of coal from the vehicle. The coal collected where:
by the auger is then placed into sealed containers for storage or N = number of increments required,
N = number of increments per vehicle,
is processed by additional sampling equipment, for example, a
a = lot size, Mg (tons), and
secondary sampler or crusher. The processed auger increments
b = amount of material per vehicle, Mg (tons).
produced by these on-line components should be placed into
sealed containers for future laboratory analysis. If N is greater than one, round it off to the nearest whole
number. If N is less than one, it is recommended that one
increment be taken from each vehicle.
5. Significance and Use
6.3.2 However, if operational considerations make the ap-
5.1 Auger sampling systems can be used to extract samples
plication of these procedures impractical, the following sug-
from trucks, railcars, barges, or static compacted stockpiles
gestions may be considered:
where the use of a full-stream mechanical sampling system
may be impractical. The samples obtained from these systems
6.3.2.1 Example 1—When more than one increment per
can be used to establish the materials’ commercial value or
vehicle is recommended but deemed impractical, then take as
constituents for quality control purposes at the shipping or
many increments as possible, but never less than one increment
receiving location of the interested parties in the transaction.
per vehicle. It should be realized that any reduction in the
The utilization of an auger system and procedures for collect-
number of increments could reduce the precision of the final
ing coal samples for subsequent analysis should be agreed
sample. In any case, obtain the same number of increments
upon by all parties concerned. Compacted stockpiles should be
from each vehicle within the lot.
no higher than the length of the auger sampler. Otherwise, the
6.3.2.2 Example 2—When N is less than one and one
deeper areas of the stockpile cannot be sampled.
increment per vehicle has not been selected as practical, then
use the following procedure: take the reciprocal of N (that is,
6. Organization and Planning of Sampling Operations
calculate 1/N ) and round off this value to the nearest whole
6.1 General Considerations—Mechanical auger sampling is number. This is now the number of vehicles per increment.
designated as Condition D, Stationary Coal Sampling. When Next, space the increments over the number of vehicles either
using augers to sample, the material taken may only be systematically or randomly while noting these precautions;
representative to the depth sampled. In addition, the parameters although systematic spacing (for example, one increment every
such as top size, degree of preparation, degree of material second vehicle for 100 vehicles) may be preferred in other
segregation, and pattern of auger placement should also be sampling practices, practical consideration must be given to the
considered. phenomena of cyclical variability which is common in this type
6.2 Consideration of Top Size—Designs of mechanical of sampling operation. If systematic spacing is not chosen,
sampling augers vary from high-powered augers with cutter random spacing (for example, distributing the 50 increments
bits drilling through the coal to be sampled, to low-powered randomly over the next 100 vehicles) must ensure the elimi-
augers designed to sample loosely compacte
...