Inside this Issue

Page

Antidrain Requirements for

Liquid Retail Motor-Fuel Devices 1

New Work Group on Measuring

Sy tems for Taxi 5

Work Group Now Forming on

Alternative Test Methods for

Commercial Measuring Devices 8

This Month in History 1

Calendar 2

This Month in

History

April 2, 1792 - The first U.S. Mint was established in Philadelphia.

April 3. 1860 - Pony Express service began.

This famous service lasted for less than two

years, and ended with the completion of

the overland telegraph.

April 3, 1783 - Washington Irving (1783-

1859) was born in New York City. He is the

author of the famous stories Rip Van Winkle

and The Legend of Sleepy Hollow.

April 8, 1913 - With the ratification of the

17th Amendment, U.S. Senators, who were

once chosen by the state legislatures,began

being selected through popular vote.

April 14, 1828 - Noah Webster published

the first American dictionary, American Dictionary of English Language.

April 18, 1775 - Paul Revere and William

Dawes made the famous “Midnight Ride” to

warn patriots that the British were coming.

1

Volume 3 Issue 2

April 16, 2012

By Marc Buttler

Liquid retail motor-fuel device (RMFD) systems come in a wide array of

shapes and sizes; however, there are certain basic requirements that are

common to all dispensers. One such requirement found in Section 3.30.

Liquid-Measuring Devices of NIST Handbook 44 (HB 44) is that all wet-hose

pressure-type dispensers are to include antidrain means. This article describes the antidrain requirement; shares an example that illustrates how

the antidrain means helps to ensure a more accurate measurement of fuel

quantity; and explains how the antidrain means is to be tested.

NIST HANDBOOK 44 REQUIREMENTS

The antidrain requirements in HB 44 apply only to “wet-hose” type devices.

As shown below, in Appendix D – Definitions of NIST HB 44, the terms “wet

hose” and “wet-hose type” are defined respectively as a discharge hose or

a type of device with a discharge hose that is intended to be full of product

at all times. RMFD systems are of the wet-hose type.

wet hose. – A discharge hose intended to be full of product at all times.

(See “wet-hose type.”)[3.30, 3.31, 3.38]

(Amended 2002)

wet-hose type. – A type of device designed to be operated with the discharge hose full of product at all times. (See “wet hose.”)[3.30, 3.32,

3.34, 3.37, 3.38]

(Amended 2002)

In contrast, the terms “dry hose” and “dry-hose type” are defined as a discharge hose or a type of device with a discharge hose that is intended to be

completely drained at the end of each delivery.

dry hose. – A discharge hose intended to be completely drained at the

end of each delivery of product. (See “dry-hose type.”)[3.30, 3.31]

(Amended 2002)

dry-hose type. – A type of device in which it is intended that the discharge hose be completely drained following the mechanical operations

involved in each delivery. (See “dry hose.”)[3.30, 3.31, 3.34, 3.35]
Calendar 2012

Registration for training in the NIST Office of

Weights and Measures is handled by Yvonne

Branden at yvonne.branden@nist.gov.

Course descriptions can be viewed on the Office of

Weights and Measures website by clicking on the

name of the course.

http://www.nist.gov/pml/wmd/calendar.cfm

April 19 (2 hours)

Webinar - Conducting an Effective Management

Review

Course No. 1210; Class No. 5174

April 23 - 27 (1 Week)

Fundamentals of Metrology

Course No. 211; Class No. 5163

April 24

Alternative Test Methods Work Group Meeting

Gaithersburg, MD

Contact: Carol Hockert at

carol.hockert@nist.gov

May 3 (2 hours)

Webinar - Internal Auditing Best Practices

Course No. 1220; Class No. 5173

May 14 - 17

Northeastern Weights & Measures Association

(NEWMA) Annual Meeting

Seekonk, MA

Contact: James Cassidy at

jcassidy@cambridgema.gov

May 20

World Metrology Day

Contact: BIPM at

http://www.bipm.org/en/convention/wmd/

May 21 - 24 (4 days)

WRAP*

Course No. 222; Class No. 5148

Cheyenne, WY

Contact: Robert Weidler at

rweidl@state.wy.us

May 20 - 24

Central Weights and Measures Association

(CWMA)

Cedar Rapids, IA

Contact: Ivan Hankins at

ivan.hankins@iowaagriculture.gov or

http://www.cwma.net/

May 23 (2 hours)

Web Meeting - Taximeter Work Group

Time: 1:30 p.m. - 3:30 p.m. EST

Contact: John Barton at john.barton@nist.gov

W&M Connection 2 Volume 3 Issue 2

The requirements for RMFD systems are found in HB 44 Section 3.30. Liquid-Measuring Devices (LMD Code). Paragraph S.3.3. Pump-discharge Unit.

of the LMD Code requires that a flexible discharge hose on a pump-discharge unit be of the wet-hose type, that is, it must remain full of liquid at

all times and not be drained between deliveries.

S.3.3. Pump-discharge Unit. – A pump-discharge unit equipped with

a flexible discharge hose shall be of the wet-hose type.

Another LMD code paragraph, S.3.6. Discharge Valve. states that a discharge

valve may only be installed in the discharge line if the device is of the wethose type. Shutoff valves other than the discharge valve (such as a breakaway valve on an RMFD) are permitted on the discharge side of the meter;

however, they must either be of the automatic or semiautomatic predetermined-stop type or else they must require a separate tool or the breaking

of a security seal to operate.

S.3.6.Discharge Valve. – A discharge valve may be installed in the discharge line only if the device is of the wet-hose type. Any other shutoff

valve on the discharge side of the meter shall be of the automatic or

semiautomatic predetermined-stop type or shall be operable only:

(a) by means of a tool (but not a pin) entirely separate from the device; or

(b) by mutilation of a security seal with which the valve is sealed

open.

The requirement for the antidrain means is described in LMD code paragraph S.3.7. Antidrain Means. Paragraph S.3.7. requires that a method be

incorporated to prevent the drainage of the discharge hose in a wet-hose

pressure-type device. Typically, the antidrain means requirement is met by

employing an antidrain valve that is designed to help keep the discharge

hose full of product at all times.

S.3.7.Antidrain Means. – In a wet-hose pressure-type device, means

shall be incorporated to prevent the drainage of the discharge hose.

(Amended 1990)

Although the subject of this article is antidrain valves on RMFDs, it will be

of interest to some to note that similar requirements also appear in other

code sections in HB 44, including: Vehicle-Tank Meters (3.31), LPG and Anhydrous Ammonia Liquid-Measuring Devices (3.32), Mass Flow Meters

(3.37), and Carbon Dioxide Liquids (3.38).

FUNCTIONING OF AN ANTIDRAIN VALVE IN A WET-HOSE TYPE

DEVICE

As mentioned earlier, a wet-hose type device is designed to keep the product discharge hose full of product at all times. Consider the segment of the

discharge hose between the meter and the nozzle shown in Figure 1 below.

As noted in the NIST training course on RMFDs, the fuel that fills the hose

at the beginning of a delivery actually passed through the meter during the

previous delivery. The assurance that the customer always receives exactly

the quantity of fuel he or she is paying for is based on the concept of displacement. Fuel metered during a delivery will initially displace exactly the

quantity contained in the discharge hose. Gravity is always acting on the

product in the hose. Left unchecked between deliveries, gravity will drain
June 18 (2 hours)

Webinar - Basic Uncertainty Concepts

Course No.1320; Class No. 5170

June 18 (2 hours)

Webinar - Documenting Traceability and Calibration Intervals

Course No. 1330; Class No. 5180

June 19 (2 hours)

Webinar - Calibration Report Evaluations

Course No. 1201; Class No. 5171

June 19 (2 hours)

Webinar - Conducting an Effective Management

Review

Course No. 1210; Class No. 5172

June 20 (2 hours)

Webinar - NISTIR 6969 SOP 8 Part 1

Course No. 30221; Class No. 5184

June 20 (2 hours)

Webinar-NISTIR 7383SOP18 Part1

Course No. 30223; Class No. 5186

June 21 (2 hours)

Webinar - NISTIR 6969 SOP 8 Part 2

Course No. 30222; Class No. 5185

June 21 (2 hours)

Webinar - NISTIR 7383 SOP Part 2

Course No. 30224; Class No. 5187

June 22 (2 hours)

Webinar - Control Charts Using PMAP Software

Course No. 30225; Class No. 5189

June 22 (2 hours)

Webinar - Uncertainties Using Kragten Spreadsheets

Course No. 30226; Class No. 5188

July 15 - 19

National Conference on Weights and Measures

(NCWM) Annual Meeting

Portland, ME

Contact: info@ncwm.net

July 29 - August 2

NCSLI Conference&Symposium

Metrology and Testing - The Business End of

Metrology

Sacramento, CA

Contact: NCSLI at http://www.ncsli.org/

August 9 (2 hours)

Webinar - Calibration Report Evaluations

Course No. 1201; Class No. 5175

(con’d pg. 4)

W&M Connection 3 Volume 3 Issue 2

at least part of the hose, leaving a void. So, in order to keep the hose full at

all times, and assure accurate deliveries, the nozzle must have some means

of preventing the hose from being partially or completely drained of fuel

after the dispenser has been shut off. Without the antidrain valve, one customer might receive more fuel than he or she has paid for by draining the

hose into his or her vehicle after the transaction. In turn, the subsequent

customer might receive less fuel than he or she paid for, because at the beginning of the delivery, fuel flowing through the meter would be displacing

air, not liquid fuel.

Figure 1. Fuel Dispenser System with Wet Hose

To keep the hose full at all times, an antidrain valve is typically located at or

very near the end of the hose where the product is delivered into a customer’s fuel tank or other container. In an RMFD system, the antidrain valve

is almost always located inside the same nozzle that contains the discharge

JULY 14 - 19 2012

PORTLAND, MAINE

Registration Information is available at:

URL: http://www.ncwm.net/content/2012-ncwm-annual-meeting
W&M Connection 4 Volume 3 Issue 21

August 16 (2 hours)

Webinar - Contract Review

Course No. 1206; Class No. 5176

August 20 - 24 (1 week)

Fundamentals of Metrology

Course No. 211; Class No. 5179

August 23 (2 hours)

Webinar - Document Control and Recordkeeping

Course No. 1204; Class No. 5177

August 30 (2 hours)

Webinar - Proficiency Testing Follow Up Actions

and Root Cause Analysis

Course No. 1240; Class No. 5181

September 6 (2 hours)

Webinar - Conducting an Effective Management

Review

Course No. 1210; Class No. 5178

September 10 - 13

NEMAP*

Course No. 227; Class No. 5154

Portland, ME

Contact: Danny Newcombe at

Danny.Newcombe@maine.gov

September 13 (2 hours)

Webinar - Internal Auditing Best Practices

Course No. 1220; Class No. 5182

September 16 - 20

Western Weights and Measures Association

(WWMA)

Breckenridge, CO

Contact: Mahesh Albuquerque at

mahesh.albuquerque@state.co.us

September 17 - 20

MidMAP*

Course No. 229; Class No. 5155

Sioux Falls, SD

Contact: Brad Stover at

brad.stover@state.sd.us

September 24 - 27

SWAP*

Course No. 228; Class No. 5156

Baton Rouge, LA

Contact: Richert Williams at

richer_w@ldaf.state.la.us

October 1 - 5

47thCIML Meeting, 14thOIML Conference

Bucharest, Romania

Contact: Charles Ehrlich at

Charles.Ehrlich@nist.gov

(con’d pg. 5)

valve near the point where the spout is attached to the body of the nozzle.

Figure 2 includes both a photograph and a diagram showing a cutaway view

of a typical nozzle and displaying the location of the antidrain valve inside.

Figure 2. Internal Components of a Typical Fuel Dispenser Nozzle

The antidrain valve is normally held shut by a spring and will only open to

allow fuel to pass through the nozzle when the fuel is under sufficient pressure to overcome the resistance of the spring. The pressure needed to push

the valve open against the spring comes from the system pump (see Figure 1). The pressure resulting from the weight of any fuel that is in the

hose higher in elevation than the antidrain valve should not be enough to

open the valve alone without additional pressure from the system pump.

The dispenser must be switched on by an operator or customer to activate

it for a fuel delivery. When the dispenser is not activated, the dispenser

control valve is closed (see Figure 1). The pump may shut off when the dispenser is inactive, or it may remain on to pressurize other dispensers if it is

shared. In either case, an inactive dispenser will not be fully pressurized

downstream of the closed control valve. When the dispenser is switched

on and becomes activated, the system pump will be on, the dispenser control valve will be open, and the dispenser will be fully pressurized. Under

these conditions, when an operator opens the discharge valve by squeezing

the discharge valve control lever, the pressure from the pump will be sufficient to push open the antidrain valve and fuel will flow from the spout of

the nozzle.

The antidrain valve is designed to allow the free flow of fuel through the

nozzle when fuel is being delivered, but it will automatically shut to prevent

draining when a transaction is not underway. The primary function of the

antidrain valve is to prevent draining of product in the forward direction.

By preventing draining in the forward direction, the antidrain valve stops
October 7 - 10

Southern Weights and Measures Association

(SWMA)

Louisville, KY

Contact: Jason Glass at (502) 573-0282

jason.glass@ky.gov

Northeastern Weights and Measures Association

(NEWMA) Interim Meeting

TBD

Contact: James Cassidy at

jcassidy@cambridgema.gov

October 18 (2 hours)

Webinar - State Laboratory Annual Submission

Process**

Course No. 1230; Class No. 5190

November 1 (2 hours)

Webinar - State Laboratory Annual Submission

Process **

Course No. 1230; Class No. 5191

November 5 - 9 (1 week)

Volume Seminar

Course No. 213; Class No. 5193

December 3 - 7 (1 week)

Intermediate Metrology Seminar

Course No. 203; Class No. 5164

2013

January 27 - 30

NationalConferenceonWeightsandMeasuresInterim Meeting

Francis Marion Hotel

Charleston, SC

Contact: info@ncwm.net

July

*Invitation Only

**LimitedtoStateLaboratoryProgramParticipants

W&M Connection 5 Volume 3 Issue 2

The NIST

Office of Weights and Measures

homepage:

http://www.nist.gov/pml/wmd/index.cfm

Please change your

browser’s bookmark.

product that has not been purchased from flowing out of the hose if someone opens the discharge valve while the dispenser is not activated.

RMFD systems contain a check valve between the storage tank and the dispenser (See Figure 1) that is in place to prevent the backward flow of fuel

into the storage tank. Although preventing flow in the reverse direction is

primarily the function of the check valve, the antidrain valve also helps to

prevent flow in the reverse direction. When the antidrain valve is tightly

sealed shut, it prevents air from entering the hose through the nozzle. If

air is not freely able to enter the hose to fill the void that would be created

by fuel draining back through the system, it creates a vacuum that aids the

check valve in preventing reverse flow. By helping to prevent draining in

the reverse direction, the antidrain valve stops product from flowing back

out of the hose and the dispenser into the storage tank, which could drain

the hose and result in the next customer being charged for product that was

not received.

PURPOSE OF THE ANTIDRAIN REQUIREMENT

The simple purpose of the requirement for an antidrain valve is to ensure

that the consumer receives all the fuel that they have paid for. Suppose,

for example, that you are at an RMFD to purchase some fuel and the hose

was empty when you first arrived because the fuel was either allowed to

drain into the vehicle that preceded you or it had drained back into the station storage tanks. The sequence of stages that occur to refill the hose are

shown in Figure 3 and explained in more detail in this example:

1. Normally, the hose will be filled with liquid at the beginning and of a

delivery as shown in diagram 1 of Figure 3.

2. If liquid is allowed to drain from the hose between deliveries, a void

is created in the hose as shown in diagram 2 of Figure 3.

3. When you arrive and activate the dispenser, it will become pressurized and product will begin to flow through the meter and into the

empty hose. The meter will measure and indicate the volume of the

fuel that passes through it. Some fuel will partially fill the hose by

NEW WORK GROUP ON MEASURING SYSTEMS FOR TAXIS

The National Institute of Standards and Technology (NIST) is forming a Work

Group (WG) to develop proposals to revise the current Taximeters Code in

NIST Handbook 44 (HB 44), Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices, to adequately address

emerging technologies used to assess charges based on time and/or distance

measurements in taxi applications and to ensure that the prescribed methodologies and standards facilitate measurements that are traceable to the International System of Units (SI).

A preliminary web-based meeting or teleconference will be held on Wednesday, May 23, 2012, from 1:30 p.m. to 3:30 p.m. Eastern time. This meeting is

intended to be a precursor to any subsequent face-to-face meeting and will

serve to provide further information and orientation regarding the objectives

of the WG. To register for this preliminary meeting, please submit your full

name, e-mail address, and phone number to Mr. John Barton by April 30,

2012. You may also contact Mr. Barton by telephone (301) 975-4002 or by email at john.barton@nist.gov. Additional information can be found on the

OWM website at: http://www.nist.gov/pml/wmd/5202.cfm.
W&M Connection 6 Volume 3 Issue 2

compressing the air that is

trapped in the hose before

you even squeeze the lever

to open the discharge valve,

as is shown in diagram 3 of

Figure 3.

4. After you open the discharge

valve to allow flow, as the

rest of the hose is filling up,

the meter will indicate that

quantity of fuel as part of

your transaction, even

though no fuel has yet made

it into your vehicle. Only

after the hose is finally completely full, as shown in diagram 4 of Figure 3, will fuel

begin to fill your vehicle.

Once your vehicle tank is full and

you are ready to end your transaction, you will release the discharge

valve and stop the flow, leaving the

hose full of fuel. In this example,

you will be charged for the amount

of fuel that you received plus the

amount that it took to fill the empty

hose. This fixed amount of fuel that

fills the hose actually belongs to the next customer that will use the dispenser after you, but they will only receive it if it

is not allowed to drain out of the hose before they arrive.

Sometimes an antidrain valve can malfunction. An antidrain valve might fail to perform its intended function for any number of reasons. If a piece of debris or particulate contamination lodges inside the nozzle, it could prevent the valve from

seating properly. A damaged seal on the valve could also result in a leak that would allow the hose to drain. If the spring

that pushes the valve shut fails, the valve may remain open or be pushed open by the small pressure that results from the

weight, or in some cases, expansion of the fuel in the hose above the nozzle. Whatever the cause, a faulty antidrain valve

can result in an incomplete delivery of the total metered quantity that is indicated, as described in the example above. A

hose with a 5/8-inch internal diameter and a length of 18 feet will contain approximately 0.3 gallons of fuel when full, and

at today’s gasoline prices, this amount can represent a value in excess of $1.001.

Another phenomenon that is often reported by consumers and weights and measures officials is commonly referred to

as “computer jump.” Computer jump can happen at the start of a transaction if the hose is empty or partially empty when

the pump first comes on to pressurize the system. As with our earlier example, fuel can flow through the meter into the

hose, filling the empty space, before the consumer ever opens the discharge valve at the nozzle to release fuel into their

vehicle. When this happens, if any quantity or money-value appears on the dispenser indication before the customer has

squeezed the discharge valve control lever, the consumer is being charged for something they have not received.

Computer jump can sometimes be observed when a dispenser is first activated after a long period of non-use. This may

indicate normal wear over time of the check valve and the antidrain valve. Slow leaks that allow a system to drain very

slowly back into the storage tank will usually not affect accuracy during normal operation because the time between

fueling events is typically shorter than the time it will take for product to drain back out of the system in a case like this.

If computer jump is observed when you first activate a dispenser, you should shut it off and immediately try again. If

computer jump is observed a second time, you should notify the equipment owner that the system is not functioning

properly and needs prompt attention. If you do not observe computer jump on the second try, you may still want to

inquire with the equipment owner about how long the dispenser will go unused between transactions and inform them

that customers may experience computer jump if the system goes unused for long periods of time and that this should

be addressed.

Figure 3. Sequence of hose filling stages during a transaction that starts

with an emply hose
SPRING SAFETY TIPS

• Change your clock - Change your battery.

• Replace your furnace filter. A dirty filter

can lower the efficiency of your

heating/cooling system and increase the

possibility of fires.

• Use the “Spring Cleaning” season as a reminder to clean the kitchen exhaust hood of

accumulated grease.

• Replace fire extingishers that have expired

charges. Homes should have multi-purpose

extingusihers readily accessible on all levels.

• Clean dryer vents of accumulated lint.

• Practice household emergency evaculation

plans, and discuss meeting places with all

family members. (Don’t forget the workplace!)

•When working outside on ladders, be

aware of your surroundings. Check to make

sure there are no electrical wires, cables, or

phone lines that might be in the way. Use a

spotter to steady the ladder.

• Check cords on outdoor lawn equipment,

and replace or repair damaged equipment.

• Store fuels for lawn equipment in a safe

manner. These should be stored in a detached structure away from the home.

• Store household lawn chemicals and fuels

out of the reach of children.

• Spring introduces “Barbeque Season.”

“Think Safety” before lighting the grill.

Check the grill over before lighting; keep it

away from structures.

REMEMBER “SAFETY FIRST”!

W&M Connection 7 Volume 3 Issue 2

CONDUCTING THE TEST OF THE ANTIDRAIN VALVE

The test of the antidrain valve is very simple to perform and should be done

near the end of an examination, after completing all the normal and special

test drafts. All tests, including the antidrain test, should be conducted

under conditions that are usual and customary with respect to the location

and use of the device, as prescribed in the General Code in HB 44 under

paragraph G-N.2. Testing with Nonassociated Equipment.

G-N.2. Testing With Nonassociated Equipment. – Tests to determine

conditions, such as radio frequency interference (RFI) that may adversely affect the performance of a device shall be conducted with

equipment and under conditions that are usual and customary with respect to the location and use of the device.

(Added 1976)

Nothing that might change the status of the hydraulic system at the location should be altered from the usual and customary conditions while testing the antidrain valve. For example, if customers can access and use other

dispensers at the facility without creating an unsafe condition, they should

be permitted to do so during the test since preventing them access could

impact the normal pressure in systems where multiple dispensers share

the same pump.

The steps to perform a test of the antidrain valve are as follows:

1. Turn the dispenser “off” by moving the lever, switch, or other control

to the “off” position in the same way that customers do following

each normal transaction.

2. With the discharge valve closed, direct the nozzle into a safe and

appropriate container (such as a metal bucket or your test measure)

so that the end of the nozzle is still visible and you will be able to

see any product exiting it. Make sure both the container and the

nozzle are grounded by placing the container on the ground or attaching a grounding cable and by touching the nozzle to the container. The container should comply with all established safety

guidelines and procedures in your jurisdiction.

3. Open the discharge valve by squeezing the discharge valve control

lever.

4. Observe whether any fuel exits from the nozzle. Discharge of a small

amount of residual product is permissible and may result from draining of the small space inside the nozzle and spout that are downstream of the antidrain valve.

5. Continue to hold open the discharge valve. After verifying that there

is no more flow, raise the hose so that the entire section that is

within 3 feet of the discharge valve is higher in elevation than the

valve (as shown in Figure 4). This will cause the weight of the fuel

in the hose that is higher in elevation than the valve to apply a small

amount of pressure on the antidrain valve. If it is set and maintained

properly, the antidrain valve spring inside the nozzle should not

allow the antidrain valve to open with only this small pressure acting

on it. It should require the higher pressure of the pump to open.

6. Continue to observe the nozzle. If no additional flow is observed

after raising the hose, the antidrain valve is working properly and

the device passes this test. Any small amount of product that may

have still been clinging to the inside of the nozzle spout that dribbles

out is permissible. However, a prolonged flow that continues beyond what might be expected to cling to the inside of the nozzle is

not acceptable.
W&M Connection 8 Volume 3 Issue 2

7. Note whether the device passed or failed

the antidrain test on your overall report and

communicate any failure to the equipment

owner.

8. Return any residual product that is in the

container into the storage of the lowest grade

of the fuel that is dispensed from that device.

CONCLUSION

The Liquid-Measuring Devices Code of NIST HB

44 includes a specification requiring RMFDs to

be equipped with means to prevent drainage

of the discharge hose between deliveries. The

antidrain means is a very important feature of

a wet-hose, pressure-type fuel dispenser and

helps to ensure that the discharge hose remains full of liquid product at all times. If it is

not functioning properly, consumers may receive less than the total indicated quantity or

may experience “computer jump” at the start of a delivery. Weights and measures officials can perform the simple test

described in this article while they are inspecting retail motor-fuel dispensers to ensure proper operation of the antidrain

means and compliance with NIST HB 44.

For questions about this article, contact Marc Buttler by email at marc.buttler@nist.gov or by phone at (301) 975-4615.

ENDNOTE

1

It is NIST policy to use the metric (SI) system of units in reference to quantities and measurements wherever practical. English

units of inches, feet, and gallons were used in this article to describe quantities related to specific RMFD indications and component

sizes as these are the units applied in the United States for RMFD commercial applications in reference to these specific quantities.

WORK GROUP NOW FORMING ON

ALTERNATIVE TEST METHODS FOR

COMMERCIAL MEASURING DEVICES

The National Institute of Standards and Technology (NIST), Office of Weights and Measures (OWM) is forming a Work

Group (WG) to examine alternative methods for testing the accuracy of commercial measuring devices including, but

not limited to retail motor-fuel dispensers. The WG will investigate the current methodology and standards (e.g., necktype volumetric field standards and associated test procedures) widely used by weights and measures officials and

service companies to test commercial measuring devices as well as proposed alternatives to ensure that the methodologies and standards facilitate measurements that are traceable to the International System of Units (SI). WG membership is open to any interested party.

An initial WG meeting will be held on Tuesday, April 24, 2012, from 10:00 a.m. to 5:00 p.m. at NIST, 100 Bureau Drive,

Gaithersburg, MD 20899. Subsequent locations for WG meetings may include NIST as well as sites suggested by WG

members offering to host meetings. WG meetings will also be conducted via web conferencing.

For further information contact: Ms. Carol Hockert, Chief, NIST, Office of Weights and Measures by telephone (301)

975-5507 or by e-mail at Carol.Hockert@nist.gov. Additional information can be obtained by visiting the OWM website

at: http://www.nist.gov/pml/wmd/atm-wrkgrp.cfm/.

Figure 4. Proper Lifting of the Hose for the Antidrain Test