Inside this Issue

Page

Clean Sweep 1

This Month in History 1

Calendar 2

This Month in 

History

August 1, 1779 – Francis Scott Key (1779 –

1843) was born in Frederick County Maryland. Key authored the poem Defense of

Fort McHenry, which became our National

Anthem in 1931 and is now known as the

Star-Spangled Banner.

August 4, 1901 – Louis “Satchmo” Armstrong (1901-1971) the jazz trumpet player

was born in New Orleans, Louisiana. He

also appeared in movies; his best known

tunes are It’s a Wonderful World and Hello,

Dolly.

August 4, 1961 – Barrack Obama, the 44th

U.S. President, was born in Honolulu,

Hawaii. 

August 6-10, 1787 – Marks the dates of the

Great Debate where the Constitutional Convention established a four-year term of office for the President, granted Congress the

right to regulate foreign trade and interstate

commerce, and the appointment of a committee to prepare the final draft of the Constitution.

(continued on page 4)

1

Volume 2 Issue 5

August 29, 2011

Clean Sweep

By John Barton

Vast amounts of bulk materials (coal, aggregate, ore, etc.) are involved in

commercial transactions where current weighing technology has provided

substantial improvements in determining accurate weights for those types

of products. However, determination of the weight or measure of these

products is not the entire basis for establishing their value. Within these

transactions, product sampling and analysis also plays a critical role in determining the fair market value of a product based on its characteristics.

Characteristics such as composition, moisture content, purity, etc. are determining factors used in the assessment of the value of the material and

have a major effect on the terms of contracts and the sale of these products.

There are a number of sampling methods for bulk materials in use as standard industry practices. The primary variation between methods of sampling is related to the mechanics involved in extracting the sample and at

what stage within the production process the sample is collected. Although

there are significant differences in the methodology, industry standards such

as ASTM D 75/D 75M–09 and E 105–04 require that whatever procedure is

used, the sample must be collected randomly and must be representative

of the total load.

One particular type of sampling procedure that has received increasing attention over the past fifteen years involves the use of “sweep samplers.”

This type of sampler system has gained popularity in the bulk materials handling industry for several reasons. Among the reasons cited for selecting

this method of sampling are:

• These systems are comparatively simple in design and provide an economical option that can be installed and placed in service on new or

existing conveyor belt lines; 

• Samples may be obtained rapidly and without the necessity of temporary stops of the conveyor belt system; and

• They offer a programmable method of obtaining a representative

sample without the need of an operator in attendance.

Sweep samplers are a type of “cross-cut” sampler that operate by removing

a cross section of material perpendicular to the direction of belt travel while
Calendar 2011

August 30 - September 1

NTETC Weighing Sector Meeting

Sacramento, CA

Contact: info@ncwm.net

September 1

Calibration Report Evaluation (Webinar)

Contact: Val Miller at val.miller@nist.gov

September 8

Calibration Method Validation (Webinar)

Contact: Val Miller at val.miller@nist.gov

September 12 - 15

Central Weights & Measures Association

(Interim Meeting)

Cedar Rapids, IA

Contact: Vicky Dempsey at

dempseyv@mcohio.org

September 25 - 29

Western Weights and Measures Assocation

(WWMA) Annual Meeting

San Luis Obisipo, CA

Contact: Brett Saum at bsaum@co.slo.ca.us

September 26 - 30 (Invitation Only)

OIML - TC 6 (Prepackaged Products)

NIST

Gaithersburg, MD

Contact: Kenneth Butcher at

Kenneth.Butcher@nist.gov

301-975-4004

October 6

Annual Submission Process (Webinar)

(Limited to State Laboratory Participants)

Contact: Val Miller at val.miller@nist.gov

October 12 - 13

Northeastern Weights & Measures Association (NEWMA) Interim Meeting

Norwich, CT

Contact: James Cassidy at

jcassidy@cambridgema.gov

October 13

Document Control & Recordkeeping (Webinar)

Contact: Val Miller at val.miller@nist.gov

(continued on page 3)

W&M Connection 2 Volume 2 Issue 5

the belt is in motion. There are a number of companies that manufacture

this type of sampling equipment, and a variety of designs are available on

these systems. The following web address can be used to access two videos

that demonstrate the mechanical action of this type of sampler. These videos

show the actual operation of the sweep-action type of sample collection and

will provide the reader a better understanding of the operation than can be

accomplished through literary description.

Link to access videos:

 http://cspot-run2.nist.gov/pml/wmd/lmdg/test-videos.cfm

In spite of their popularity, these systems do present concerns within the

community of belt-conveyor scale users, manufacturers, and regulators. In

proportion with the increase in the number of systems being installed, questions have arisen regarding the operational mode of sweep-samplers during

the testing of the belt-conveyor scale systems with which they are associated.

Additional concerns regarding the potential effects that sweep samplers may

have on belt-conveyor scales during normal operation are also being expressed. As a result, answers are being sought regarding recommendations

or requirements for locating the sampling system, relative to a belt-conveyor

scale in the same belt line. 

The National Institute of Standards and Technology (NIST), Weights and Measures Division (WMD) has received a number of recent requests seeking guidance for the correct installation requirements for these samplers in relation

to a belt-conveyor scale. While there are no specific references to sampling

systems in NIST Handbook 44 (HB 44), Specifications, Tolerances, and Other

Technical Requirements for Weighing and Measuring Devices, some industry

personnel have referenced HB 44 requirements pertaining to the placement

of other conveyor components such as: training idlers; skirting; loading

points; etc. The minimum distances required in HB 44 for placement of these

belt-conveyor features are based on evidence that contact made with the

belt by these features will impart a measurable degree of influence to the

belt tension and/or speed, thereby affecting the performance of the belt-conveyor scale. In the same sense, contact with the belt by the mechanical operation of sweep samplers could potentially have similar effects on the

weighing process.

In an effort to acquire information that could be used to establish standards,

several U.S. manufacturers of sweep style samplers have been contacted by

NIST WMD to determine if the engineering departments of those companies

supplied their customers with guidance on this issue. None of the manufacturers who responded have policies where their customers are provided instruction or recommendation on where to locate the samplers to negate any

effect the sampler could have on a belt-conveyor scale’s performance. Service

technicians and installers of belt-conveyor systems have pointed out the lack

of requirements in HB 44 that specifically address the placement of sampling

equipment. 

These types of samplers are capable of operating autonomously and repeatedly as set in their programming. Given the split-second nature of contact

made with the belt-conveyor, one might assume that any effect would be
October 21 - 22

NTETC Measuring Sector

Norfolk, VA

Contact: info@ncwm.net

October 23 - 26 

Southern Weights & Measures Association

Norfolk, VA

Contact: Dale Saunders at 

dale.saunders@vdacs.virginia.gov

November 10

Annual Submission Process (Webinar)

(Limited to State Laboratory Participants)

Contact: Val Miller at val.miller@nist.gov

Calendar 2012

January 22 - 25

NCWM Interim Meeting

New Orleans, LA

Contact: info@ncwm.net

May 14 - 17

Northeastern Weights & Measures Association

(NEWMA) Annual Meeting

Seekonk, MA

Contact: James Cassidy at

jcassidy@cambridgema.gov

May 20 - 24

Central Weights and Measures Association

(CWMA)

Cedar Rapids, IA

Contact: Ivan Hankins at 

ivan.hankins@iowaagriculture.gov

October 16 - 17

Northeastern Weights and Measures Association

(NEWMA) Interim Meeting

TBD

Contact: James Cassidy at

jcassidy@cambridgema.gov

CONTACTS FORWEBINARS

• Lab Metrology: Val Miller at val.miller@nist.gov or

view the Laboratory Metrology group webpage at: 

http://www.nist.gov/pml/wmd/labmetrology/webina

rs.cfm

• Devices: Tina Butcher at tina.butcher@nist.gov

• Laws & Metric: David Sefcik at david.sefcik@nist.gov

or Lisa Warfield at lisa.warfield@nist.gov

Additional details on the above calendar items

can be found at: 

http://ts.nist.gov/WeightsAndMeasures/calendar3.cfm

W&M Connection 3 Volume 2 Issue 5

minimal. Consider, however, that a sampler is programmable and may be set

to operate several times within relatively short time periods. Although the

number of samples required will vary based on time of operation or material

flow, operators of these sampling systems have provided examples of sampling rates, some as often as once or twice per minute. The cumulative effect

could have a significant impact at the conclusion of an extended weighing

process. 

Placement of samplers downstream of the belt scale will result in product

that has been included as a portion of the full load to be removed from the

delivery of that entire load. Typically the amount of product needed for sampling is small and the amount of a single sample in relation to a totalized load

would generally be insignificant. The removal of product from the stream of

flow repeatedly throughout the process, however, could conceivably have a

significant effect on the totalized load. Because this method of sampling

would result in a diversion of measured portions of the product, many

weights and measures authorities would consider this method of operation

unacceptable.

In addition to the placement of sweep samplers, other concerns involving

this type of sampler include the recognition that repeated sample collection

during an entire weighing process results in areas of the belt stream that are

devoid of product. This condition is in contrast to the optimum operating

conditions of belt-conveyor scales that stipulate a steady and consistent flow

of product across the weighing element.

When responding to requests seeking guidance for the proper location of the

sampling equipment, NIST WMD has received anecdotal information indicating that sampling equipment is routinely being turned off during official testing of belt-conveyor scales in many, if not most instances. HB 44 General

Code addresses this issue as follows: 

G-UR.3.2. Associated and Nonassociated Equipment. – A device

shall meet all performance requirements when associated or nonassociated equipment is operated in its usual and customary manner

and location.

(Added 1976)

This requirement indicates that the intent of a performance test is to evaluate

a system when all of its components are in operation. Sampling systems are

typically in use during normal operations. Therefore, any official testing

should be performed with the samplers running. Considering the sweep sampler’s operation, it is reasonable to assume that the potential exists for a belt

scale located on the same conveyor to be affected by the mechanical action

of the sample being taken from the belt. This would be justification for the

recommendation that sampling systems of this type be in operation during

official performance evaluations.

The NIST WMD response to many questions regarding weighing and measuring devices is based on existing standards and an experienced knowledge

base. The response to questions posed regarding location of sweep sampler

installation, however, requires information that is not yet available. Any stud-
W&M NEWS WEB LINKS

(IOWA) STATE LAB EARNS RECOGNISTION

The new lab receives NIST recognition a year ahead of schedule. Read further

here:

http://www.newtondailynews.com/articles/2011/06/13/r_pfurmm3mseub07wdtowu_q/index.xml

WATER & LOW OCTANE FOUND AT LOCAL GAS PUMPS

Read about the gas pumps in some Texas gas station locations .

http://dfw.cbslocal.com/2011/05/12/state-inspections-find-water-lower-octane-at-north-texas-gasstations/

GAS PRICES: WHAT ARE YOU PAYING FOR?

Gasoline inspectors crack down on substandard gas that could harm your engine.

http://dfw.cbslocal.com/2011/05/12/state-inspections-find-water-lower-octaneat-north-texas-gas-stations/

SPECIAL REPORT: INSPECTORS MAKE SURE BARCODES SCAN CORRECT

PRICE

Raleigh, NC - Millions of Americans depend on barcodes to ring up pruchases correctly.

http://www2.nbc17.com/news/2011/apr/28/special-report-scanning-savings-pt-1-ar988497/

W&M Connection 4 Volume 2 Issue 5

August 9, 1974 – Richard Nixon resigned his

presidency because of the Watergate scandal. He is the only U.S. President to ever resign his office.

August 10, 1874 – President Herbert

Hoover (1874-1964) was the first President

born west of the Mississippi River. He was

born in West Branch, Iowa.

August 12, 1881 – Cecil B. DeMille (1881-

1959) was born in Ashfield, Massachusetts.

He was a great film pioneer and produced

over 70 major films.

August 13, 1818 – Women’s rights pioneer

Lucy Stone (1818-1893) was born near

West Brookfield, Massachusetts. Her life

was dedicated to the abolition of slavery

and the emancipation of women. She also

was instrumental in the founding of the

American Suffrage Association. 

August 13, 1860 – Annie Oakley (1860-

1926) was born in Darke County, Ohio. She

was a Wild West performer and famous for

her shooting ability. For 17 years, she performed in Buffalo Bill’s Wild West Show.

August 15, 1969 – The three day concert,

Woodstock, was held in a field near Yasgur’s

Farm at Bethel, New York.

August 16, 1896 – The start of the Great

Klondike Gold Rush began when gold was

discovered in a tributary of the Klondike

River in Alaska.

August 16, 1977 –Elvis Presley, a music legend, died in Memphis, Tennessee, at the

age of 42. 

August 17, 1786 – Davy Crockett (1786-

1836), an American frontiersman, was born

in Hawkins County, Tennessee. Crockett was

a farmer, scout, and politician who died defending the Alamo in Texas. 

August 18, 1920 – Women were granted

the right to vote with the ratification of the

19th Amendment to the U.S. Constitution.

August 21, 1959 – On this day, Hawaii was

admitted to the Union as the 50th state. 

MORE THIS MONTH IN HISTORY

ies performed in an attempt to gather data would be complex in nature and

would have to overcome difficulties, most notably the need to avoid any interference with normal plant operations at the testing site. To date, no equipment manufacturers or industrial operations have been identified as a

potential source for this data. Provided that a suitable site could be located,

the process of data collection would also require personnel to perform the

required test procedures, obtain all necessary test equipment, and procure

and weigh material to use in the testing. 

Many interested parties involved with the use of belt-conveyor scales and associated equipment would stand to benefit from further data collection of

sweep sampler operation and impact. These parties are anxious to receive

guidance that can only be based on legitimate data. For comments or information relevant to the content of this article, please contact John Barton at

(301) 975-4002 or by e-mail at john.barton@nist.gov.

Acknowledgements:

Videos courtesy of John B. Long Company

Knoxville, Tennessee U.S.A.

Internet Website: http://www.jblco.com/

A.M. Long, Author of “Maintaining Coal Sampling Systems, Managing Objectives with Limited Resources”