# Section 3

## Page

3.30. Liquid-Measuring Devices 3-3

**3.31. Vehicle-Tank Meters 3-23**

**3.32. LPG and Anhydrous Ammonia Liquid-Measuring Devices 3-31**

3.33. Hydrocarbon Gas Vapor-Measuring Devices 3-41

**3.34. Cryogenic Liquid-Measuring Devices 3-49**

**3.35. Milk Meters 3-57**

**3.36. Water Meters 3-63**

**3.37. Mass Flow Meters 3-67**

**3.38. Carbon Dioxide Liquid-Measuring Devices - Tentative Code 3-77**

Note: In this section of Handbook 44, the reference temperature for the
temperature compensation of refined petroleum products is shown as
\"15 C (60 F).\" Although these values are not exact equivalents, they
reflect industry usage when the SI and inch-pound units are used in
measurements.

### Sec. 3.30. Liquid-Measuring Devices

#### A. Application

**A.1.** - This code applies to:

(a) devices used for the mea­surement of liquids, including liquid fuels
    and lubricants, and

(b) wholesale devices used for the measurement and delivery of
    agri-­chemical liquids such as fertilizers, feeds, herbicides,
    pesticides, insec­ticides, fun­gicides, and defoliants.

> (Added 1985)

**A.2.** - This code does not apply to:

(a) meters mounted on vehicle tanks (see Sec. 3.31. Code for
    Veh­icle-­Tank Meters),

(b) devices used for dispensing liquefied petroleum gases (see Sec.
    3.32. Code for Liquefied Petroleum Gas and Anhydrous Ammonia
    Liquid-Measuring Devices),

(c) devices used for dispensing other liquids that do not remain in a
    liquid state at atmospheric pressures and temperatures,

(d) water meters,

(e) devices used solely for dispensing a product in connection with
    opera­tions in which the amount dispensed does not affect customer
    charges, or

(f) mass flow meters (see Sec. 3.37. Code for Mass Flow Meters.)

> (Added 1994)

**A.3.** - In addition to the requirements of this code,
liquid-measuring devices shall meet the requirements of Section 1.10.
General Code.

#### S. Specifications

**S.1. Indicating and Recording Elements and Re­corded Repre­senta­tions.**

**S.1.1. General.** - A liquid-measuring device:

(a) shall be equipped with a primary indicating element, and

(b) may be equipped with a primary recording element.

> **S.1.2. Units.** - A liquid-measuring device shall indicate, and
> record if the device is equipped to record, its deliveries in liters,
> gallons, quarts, pints, or binary-submultiples or decimal subdivisions
> of the liter or gallon.
>
> (Amended 1987, 1994)
>
> **S.1.2.1. Retail Motor­-Fuel Devices.** - Deliveries shall be
> indicated and recorded, if the device is equipped to record, in liters
> or gallons and decimal sub­divisions or fractional equivalents thereof.
>
> (Added 1979)
>
> **S.1.2.2. Agri-­Chemical Liquid Devices.**
>
> **S.1.2.2.1. Liquid Measure.** - Deliveries shall be indicated and
> recorded in liters or gallons and decimal sub­divisions or fractional
> e­quivalents thereof.
>
> **S.1.2.3. Value of Smal­lest Unit.** - The value of the smallest unit
> of indi­cated delivery, and recorded delivery if the device is equipped
> to record, shall not exceed the equivalent of:

(a) 0.5 L (1 pt) on retail devices;

(b) 5 L (1 gal) on wholesale devices.

> This require­ment does not apply to manually operated devices equipped
> with stops or stroke-limiting means.
>
> (Amended 1983 and 1986)
>
> **S.1.3. Advancement of Indicating and Record­ing Ele­ments.** - It
> shall not be possible to advance primary indicating and recording
> elements except by the mechanical operation of the device. Clearing a
> device by advanc­ing its elements to zero is permitted, but only if:

(a) once started, the advancement movement cannot be stopped until zero
    is reached, and

(b) in the case of indicating elements only, such elements are
    auto­matically obscured until the elements reach the correct zero
    position.

> **S.1.4. Graduations.**

**S.1.4.1. Length.** - Graduations shall be varied in length so that
they may be conveniently read.

**S.1.4.2. Width.** - In a series of graduations, the width of:

(a) every graduation shall be at least 0.2 mm (0.008 in) but not greater
    than the minimum clear interval between gradua­tions, and

(b) main gradua­tions shall be not more than 50 percent greater than the
    width of subordinate gradua­tions.

> **S.1.4.3. Clear Inter­val Between Gr­adua­tions.** -The clear interval
> between graduations shall be not less than 1.0 mm (0.04 in). If the
> gradua­tions are not parallel, the measure­ment shall be made:

(a) along the line of movement of the tip of the index of the in­dicator
    as it passes over the gradua­tions, or

(b) if the indicator extends over the entire length of the gradua­tions,
    at the point of widest separation of the gradua­tions.

**S.1.5. In­dicators.**

> **S.1.5.1. Symmetry.** - The portion of the index of an indicator
> associated with the graduations shall be symmetrical with respect to
> the graduations.
>
> **S.1.5.2. Length.**

(a) If the indicator and the graduations are in different planes, the
    index of the indicator shall extend to each graduation with which it
    is to be used.

(b) If the indicator is in the same plane as the graduations, the
    distance between the index of the indicator and the ends of the
    graduations, measured along the line of the graduations, shall be
    not more than 1.0 mm (0.04 in).

> **S.1.5.3. Width.**

(a) *The index of an indicator shall not be wider than the width of the
    narrowest graduation.*

> *\[Nonretroactive as of January 1, 2002.\]*
>
> (Amended 2000)

(b) If the index of an indicator extends over the entire length of a
    graduation, it shall be of uniform width throughout the portion that
    coincides with the graduation.

> **S.1.5.4. Clear­ance.** - If the indicator and the graduations are in
> dif­ferent planes, the clearance between the index of an indicator and
> the plane of the graduations shall be no greater than 1.5 mm
> (0.06 in).
>
> **S.1.5.5. Parallax.** - Parallax effects shall be reduced to the
> practical minimum.
>
> **S.1.6. Operating Requirements, Retail Devices (Except Slow ­Flow
> Meters).**
>
> **S.1.6.1. Indication of Delivery.** - The device shall auto­matically
> show on its face the initial zero condition and the quantity delivered
> (up to the nominal capacity).
>
> However, the first 0.03 L (or 0.009 gal) of a delivery and its
> as­sociated total sales price need not be indicated.
>
> (Amended 1982)

**S.1.6.2. Provisions for Power Loss.**

> ***S.1.6.2.1. Trans­action Information.** - In the event of a power
> loss, the information needed to complete any transac­tion in progress
> at the time of the power loss (such as the quantity and unit price, or
> sales price) shall be determinable for at least 15 minutes at the
> dispenser or at the console if the console is accessible to the
> customer.*
>
> *\[Nonretroactive as of January 1, 1983.\]*
>
> ***S.1.6.2.2. User Informa­tion.** - The device memory shall retain
> information on the quantity of fuel dispensed and the sales price
> totals during power loss.*
>
> *\[Nonretroactive as of January 1, 1983.\]*

**S.1.6.3. Return to Zero.**

(a) The primary indicating elements, and primary recording elements if
    the device is equipped to record, shall be readily returnable to a
    definite zero indication. However, a key-lock operated or other
    self-operated device may be equip­ped with cumulative indicating or
    recording elements, provided that it is also equipped with a
    zero-return indicating element.

(b) It shall not be possible to return primary indicating elements, or
    primary recording elements beyond the correct zero position.

(Amended 1972)

**S.1.6.4. Display of Unit Price and Pro­duct Identity.**

**S.1.6.4.1. Unit Price.**

(a) A computing or money-operated device shall be able to display on
    each face the unit price at which the device is set to compute or to
    dispense.

(b) *Whenever a grade, brand, blend, or mixture is offered for sale from
    a device at more than one unit price, then all of the unit prices at
    which that product is offered for sale shall be displayed or shall
    be capable of being displayed on the dispenser using controls
    available to the customer prior to the delivery of the product. It
    is not necessary that all of the unit prices for all grades, brands,
    blends, or mixtures be simultaneously displayed prior to the
    delivery of the product. This subsection shall not apply to fleet
    sales, other contract sales, or truck refueling sales (e.g., sales
    from dispensers used to refuel trucks).*

> *\[Nonretroactive as of January 1, 1991.\]*

(Amended 1989 and 1997)

**S.1.6.4.2. Product Identity.**

(a) A device shall be able to conspicuously display on each side the
    identity of the product being dispensed.

(b) A device designed to dispense more than one grade, brand, blend, or
    mixture of product also shall be able to display on each side the
    identity of the grade, brand, blend, or mixture being dispensed.

**S.1.6.5. Money-Value Computations.**

(a) A computing device shall compute the total sales price at any
    single-purchase unit price (i.e., excluding fleet sales, other price
    contract sales, and truck stop dispensers used only to refuel
    trucks) for which the product being measured is offered for sale at
    any delivery possible within either the measure­ment range of the
    device or the range of the computing ele­ments, whichever is less.

> *\[Nonretroactive as of January 1, 1991\]*

(b) The analog sales price indicated for any delivered quantity shall
    not differ from a mathematically computed price (quan­tity x unit
    price = total sales price) by an amount greater than the value in
    Table 1.

(Amended 1984, 1989, and 1993)

> **S.1.6.5.1. Money-­Value Divisions, Analog.** - The values of the
> graduated intervals representing money values on a comput­ing type
> device shall be no greater than those in Table 1.
>
> (Amended 1991)
>
> **S.1.6.5.2. Money-Value Divisions, Digital.** - A comput­ing type
> device with digital indications shall comply with the require­ments of
> paragraph G.S.5.5. Money Values, Mathematical Agreement, and the total
> price computation shall be based on quantities not exceeding 0.05 L
> for devices indicating in metric units and 0.01-gal. intervals for
> devices indicating in inch-pound units.
>
> (Added 1980)
>
> ***S.1.6.5.3. Auxiliary Elements.** - If a system is equipped with
> auxiliary indications, all indicated money value divisions of the
> auxiliary element shall be identical with those of the primary
> element.*
>
> *\[Nonretroac­tive as of January 1, 1985.\]*
>
> ***S.1.6.5.4. Selection of Unit Price.** - Except for dispensers used
> exclusively for fleet sales, other price contract sales, and truck
> refueling (e.g., truck stop dispensers used only to refuel trucks),
> when a product or grade is offered for sale at more than one unit
> price through a computing device, the selection of the unit price
> shall be made prior to delivery using controls on the device or other
> customer-activated controls.* A system shall not permit a change to
> the unit price during delivery of product.
>
> *\[Nonretroactive as of January 1, 1991.\]*
>
> (Added 1989)(Amended 1991, 1992, 1993, and 1996)
>
> ***S.1.6.5.5. Display of Quantity and Total Price.** - When a delivery
> is completed, the total price and quantity for that transaction shall
> be displayed on the face of the dispenser for at least 5 minutes or
> until the next transaction is initiated by using controls on the
> device or other customer-activated controls.*
>
> *\[Nonretroactive as of January 1, 1994.\]*
>
> (Added 1992)(Amended 1996)
>
> **S.1.6.6. Agreement Between Indica­tions.** - When a quantity value
> indicated or recorded by an auxiliary element is a derived or computed
> value based on data received from a retail motor fuel dis­penser, the
> value may differ from the quantity value displayed on the dispenser,
> provided the following conditions are met:

(a) all total money values for an individual sale that are indi­cated or
    recorded by the system agree; and

(b) *within each element, the values indicated or recorded meet the
    formula (quantity x unit price = total sales price) to the closest
    cent.*

> *\[Nonretroactive as of January 1, 1988.\]*
>
> (Added 1985)(Amended 1987 and 1988)
>
> ***S.1.6.7. Recorded Representations. -** Except for fleet sales and
> other price contract sales, a printed receipt providing the following
> information shall be available through a built-in or separate
> recording element for all transactions conducted with point-of-sale
> systems or devices activated by debit cards, credit cards, and/or
> cash:*

(a) *the total volume of the delivery,*

(b) *the unit price,*

(c) *the total computed price, and*

(d) *the product identity by name, symbol, abbreviation, or code
    number.*

> *\[Nonretroactive as of January 1, 1986.\]*
>
> (Added 1985) (Amended 1997)
>
> **S.1.6.8. Lubricant Devices, Travel of Indicator.** -The indicator
> shall move at least 2.5 cm (1 in) in relation to the graduations, if
> provided, for a delivery of 0.5 L (1 pt).

**S.1.7. Operating Re­quirements, Wholesale Devices Only.**

> **S.1.7.1. Travel of Indicator.** - A wholesale device shall be
> readily operable to deliver accurately any quantity from 200 L
> (50 gal) to the capacity of the device. If the most sensitive element
> of the indicating system utilizes an indicator and graduations, the
> relative movement of these parts corresponding to a delivery of 4 L
> (1 gal) shall be not less than 5 mm (0.20 in).
>
> (Amended 1987)
>
> **S.1.7.2. Money Val­ues­-Math­ematical Agree­ment.** - Any digital
> money-value indication and any recorded money value on a
> computing-type device shall be in mathematical agree­ment with its
> associated quantity indication or representation to within one cent of
> money value.

**S.2. Measuring Elements.**

**S.2.1. Vapor Elimi­nation.**

(a) A liquid-measuring device shall be equipped with a vapor or air
    elimi­nator or other automatic means to prevent the passage of vapor
    and air through the meter.

(b) Vent lines from the air or vapor eliminator shall be made of metal
    tubing or other rigid material.

(Amended 1975)

**S.2.1.1. Vapor Elimi­nation on Loading Rack Metering Systems.**

(a) A loading rack metering system shall be equipped with a vapor or air
    > eliminator or other automatic means to prevent the passage of
    > vapor and air through the meter unless the system is designed or
    > operationally controlled by a method, approved by the weights and
    > measures jurisdiction having control over the device, such that
    > air and/or vapor cannot enter the system.

(b) Vent lines from the air or vapor eliminator (if present) shall be
    made of metal tubing or other rigid material.

(Added 1994)

> **S.2.2. Provision for Sealing. -** Adequate provision shall be made
> for an approved means of security (e.g., data change audit trail) or
> physically applying security seals in such a manner that no adjustment
> may be made of:
>
> \(a\) any measurement element, or
>
> \(b\) any adjustable element for controlling delivery rate when such
> rate tends to affect the accuracy of deliveries.
>
> When applicable, the adjust­ing mechanism shall be readily accessible
> for purposes of affixing a security seal.
>
> *(c) Audit trails shall use the format set forth in Table S.2.2.
> \[Nonretroactive as of January 1, 1995.\]*

(Amended 1991, 1993, and 1995)

> **S.2.3. Direc­tional Flow Valves.** - Valves intended to prevent
> reversal of flow shall be automatic in operation.

**S.2.4. Stop Mecha­nism.**

> **S.2.4.1. Indication.** - The delivery for which the device is set
> shall be conspicuously indicated.
>
> (Amended 1983)
>
> **S.2.4.2. Stroke Limiting Ele­ments.** - Stops or other stroke
> limiting elements subject to direct pressure or impact shall be:

(a) made secure by positive, nonfrictional engage­ment of these elements;
    and

(b) adjustable to provide for deliveries within tolerances.

> (Amended 1983)
>
> **S.2.4.3. Setting.** - If two or more stops or other elements may be
> selectively brought into operation to permit predetermined quan­tities
> of deliveries,
>
> \(a\) the position for the proper setting of each such element shall
> be accurately defined; and
>
> \(b\) any inadvertent displace­ment from the proper setting shall be
> obstructed.
>
> (Amended 1983)
>
> **S.2.5. Zero-Set-Back Interlock, Retail Motor-Fuel Devices.** - A
> device shall be constructed so that:

(a) after a delivery cycle has been completed by moving the starting
    lever to any position that shuts off the device, an automatic
    interlock pre­vents a subsequent delivery until the indicating
    elements, and recording elements if the device is equipped and
    ac­tivated to record, have been returned to their zero positions;

(b) the discharge nozzle cannot be returned to its designed hanging
    position (that is, any position where the tip of the nozzle is
    placed in its de­signed receptacle and the lock can be inserted)
    until the starting lever is in its designed shut-off position and
    the zero-set-back interlock has been engaged; and

(c) in a system with more than one dispenser sup­plied by a single pump,
    an effective auto­matic control valve in each dispenser pre­vents
    prod­uct from being delivered until the indicating elements on that
    dispenser are in a correct zero position.

(Amended 1981 and 1985)

> ***S.2.6. Temperature Determination and Wholesale Devic­es.** - For
> test pur­poses, means shall be provided to deter­mine the tempera­ture of
> the liquid either:*

(a) *in the liquid chamber of the meter, or*

(b) *immediately adjacent to the meter in the meter inlet or discharge
    line.*

> *\[Non­retroactive as of January 1, 1985.\]*
>
> (Added 1984)(Amended 1986)
>
> **S.2.7. Wholesale Devices Equipped with Auto­matic Temperature
> Compensators.**
>
> **S.2.7.1. Automatic Temperature Compensa­tion.** - A device may be
> equipped with an auto­matic means for adjusting the indica­tion and
> registra­tion of the measured volume of product to the volume at 15 C
> (60 F).
>
> **S.2.7.2. Provision for Deac­tivating.** - On a de­vice equipped with
> an automatic temperature-compensating mechanism that will indicate or
> record only in terms of gallons compensated to 15 C (60 F), provision
> shall be made for deactivating the automatic tempera­ture-­com­pensating
> m­ech­anism so that the meter can indicate, and record if it is equipped
> to record, in terms of the un­compensated volume. (Amended 1972)
>
> **S.2.7.3. Provision for Sealing Automatic Tem­perature Com­pensating
> Systems.** - Provision shall be made for applying security seals in
> such a manner that an automatic temperature­-com­pensating system cannot
> be disconnected and that no adjustment may be made to the system
> without breaking the seal.
>
> **S.2.7.4. Temperature Determination with Au­toma­tic Tempera­ture
> Com­pen­sa­tion.** - For test purposes, means shall be provided (e.g.,
> ther­mometer well) to deter­mine the tempera­ture of the liquid either:
>
> \(a\) in the liquid chamber of the meter, or
>
> \(b\) immediate­ly adjacent to the meter in the meter inlet or
> discharge line.
>
> (Amended 1987)
>
> **S.2.8. Exhaus­tion of Supply, Lubrica­nt Devices Oth­er than Meter
> Types.** - When the level of the supply of lubricant becomes so low as
> to com­pro­mise the accuracy of measure­ment, the device shall:

(a) become inoperable automati­cally, or

(b) give a conspicuous and distinct warning.

**S.3. Discharge Lines and Valves.**

> **S.3.1. Diversion of Measured Liquid.** - No means shall be provided
> by which any measured liquid can be diverted from the measuring
> chamber of the meter or its discharge line. Two or more delivery
> outlets may be installed only if automatic means are provided to
> ensure that:

(a) liquid can flow from only one outlet at a time, and

(b) the direction of flow for which the mechanism may be set at any time
    is clearly and conspicuously indicated.

> A manually controlled outlet that may be opened for purging or
> draining the measuring system or for recirculating product in
> suspension shall be permitted only when the system is measuring food
> products or agri-chemicals. Effective means shall be provided to
> prevent passage of liquid through any such outlet during normal
> operation of the measuring system and to inhibit meter indications (or
> advancement of indications) and recorded representations while the
> outlet is in operation.
>
> (Amended 1991, 1995, and 1996)
>
> **S.3.2. Exceptions.** - The provisions of S.3.1. Diversion Prohibited
> shall not apply to truck refueling devices when diversion of flow to
> other than the receiving vehicle cannot readily be accomplished and is
> readily apparent. Allowable deterrents include, but are not limited
> to, physical barriers to adjacent driveways, visible valves, or
> lighting systems that indicate which outlets are in operation, and
> explanatory signs;

(Amended 1982, 1990,1991, and 2002)

> **S.3.3. Pum­p-Discharge Unit.** - A pump-discharge unit equipped with
> a flexible discharge hose shall be of the wet-hose type.
>
> **S.3.4. Gravity­-Discharge Unit.** - On a gravity-dis­charge unit:

(a) the discharge hose or equivalent pipe shall be of the dry-hose type
    with no shutoff valve at its outlet end unless the hose or pipe
    drains to the same level under all conditions of use;

(b) the dry hose shall be sufficiently stiff and only as long as
    neces­sary to facilitate drainage;

(c) an auto­matic vacuum breaker, or equivalent mechanism, shall be
    incor­porated to prevent siphoning and to ensure rapid and com­plete
    drain­age; and

(d) the inlet end of the hose or outlet pipe shall be high enough to
    ensure complete drainage.

> **S.3.5. Discharge Hose, Reinforcement.** - A discharge hose shall be
> reinforced so that the performance of the device is not affected by
> the expansion or contrac­tion of the hose.
>
> **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.

> **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)

**S.4. Marking Re­quirements.**

> **S.4.1. Limitation on Use.** - The limitations on its use shall be
> clearly and permanently marked on any de­vice intended to mea­sure
> accurately only:

(a) products having particular properties; or

(b) under specific installation or operating condi­tions; or

(c) when used in conjunc­tion with specific accesso­ry equipment.

> **S.4.2. Air Pressure.** - If a device is operated by air pressure,
> the air pressure gauge shall show by spe­cial graduations or other
> means the maxi­mum and mini­mum working pressures recommended by the
> manufacturer.
>
> **S.4.3. Wholesale Devices.**
>
> **S.4.3.1. Discharge Rates.** - A wholesale device shall be marked to
> show its designed maximum and minimum discharge rates. However, the
> minimum discharge rate shall not exceed 20 percent of the maxi­mum
> dis­charge rate.
>
> **S.4.3.2. Temperature Compensation.** - If a de­vice is equipped with
> an automatic tempera­ture compen­sator, the primary indicating ele­ments,
> recording elements, and recorded rep­resen­ta­tion shall be clearly and
> con­spicuously marked to show that the volume delivered has been
> adjusted to the volume at 15 C (60 F).
>
> ***S.4.4. Retail Devices.***
>
> ***S.4.4.1. Discharge Rates.** - On a retail device with a de­signed
> maximum dis­charge rate of 115 L (30 gal) per minute or greater, the
> maxi­mum and mini­mum discharge rates shall be marked on an exterior
> surface of the device and shall be visible after instal­la­tion. The
> minimum discharge rate shall not exceed 20 percent of the maximum
> discharge rate.*
>
> *\[Non­retroac­tive as of January 1, 1985.\]*
>
> (Added 1984)(Amended 2002)
>
> ***S.4.4.2. Location of Marking Information; Retail Motor-Fuel
> Dispensers.** -- The required marking information in the General Code,
> Paragraph G-S.1. shall appear as follows:*

(a) *Placement of this information shall not be on a portion of the
    device that can be readily removed or interchanged without the use
    of a tool separate from the device.*

(b) *The information shall appear 24 inches to 60 inches from the base
    of the dispenser when placed on the outside of the device.*

(c) *When placed behind an access door or panel the information shall
    appear 24 inches to 60 inches from the base of the dispenser in a
    readily legible position. The use of a dispenser key shall not be
    considered a tool separate from the device.*

> *\[Nonretroactive as of January 1, 2003\]*
>
> (Added 2002)

***S.5. Totalizers for Retail Motor-Fuel Dispensers. -** Retail
motor-fuel dispensers shall be equipped with a nonresettable totalizer
for the quantity delivered through the metering device.*

*\[Nonretroactive as of January 1, 1995.\]*

(Added 1993; Amended 1994)

### N. Notes

**N.1. Test Liquid.**

> **N.1.1. Type of Liquid.** - The liquid used for testing a
> liquid-measur­ing device shall be the type the device is used to
> measure, or another liquid with the same general physical
> characteristics.
>
> **N.1.2. Labeling.** - Following the completion of a successful
> examina­tion of a wholesale device, the weights and measures official
> should attach a label or tag indicating the type of liquid used during
> the test.

**N.2. Vol­ume Change.** - Care shall be taken to minimize changes in
volume of the test liquid due to temperature changes and evapora­tion
losses.

**N.3. Test Drafts.**

> **N.3.1. Retail Piston-­Type and Visible-­Type Devices.** - Test drafts
> shall include the full capacity delivery and each intermediate
> delivery for which the device is designed.
>
> **N.3.2. Slow Flow Meters.** - Test drafts shall be equal to at least
> four times the minimum volume that can be measured and indicated
> through either a visible indication or an audible signal.
>
> **N.3.3. Lubricant Devices.** - Test drafts shall be 1 L (1 qt).
> Additional test drafts may include 0.5 L (1 pt), 4 L (4 qt), and 6 L
> (6 qt).
>
> **N.3.4. Other Retail Devices.** - On devices with a designed maximum
> dis­charge rate of:

(a) less than 80 L (20 gal) per minute, tests shall include drafts of
    one or more amounts, including a draft of at least 19 L (5 gal).

(b) 80 L (20 gal) per minute or greater, tests shall include drafts of
    one or more amounts, including a draft of at least the amount
    deliv­ered by the device in one minute at the maxi­mum flow rate of
    the installa­tion.

(Amended 1984)

> **N.3.5. Wholesale Devices.** - The delivered quantity should be equal
> to at least the amount delivered by the device in one minute at its
> maximum discharge rate, and shall in no case be less than 200 L (50
> gal).
>
> (Amended 1987 and 1996)

**N.4. Testing Procedures.**

> **N.4.1. Normal Tests.** - The \"normal\" test of a device shall be
> made at the maximum discharge flow rate developed under the conditions
> of installation. Any additional tests conducted at flow rates down to
> and including one-half of the sum of the maximum discharge flow rate
> and the rated minimum discharge flow rate shall be considered normal
> tests.
>
> (Amended 1991)
>
> **N.4.1.1. Wholesale Devices Equipped with Auto­matic
> Temperature-Comp­ensating Sys­tems.** - On wholesale devices equipped
> with automatic tem­perature compensating systems, normal tests shall be
> conducted:

(a) by comparing the compensated volume indi­cated or recorded to the
    actual deliv­ered volume corrected to 15 C (60 F); and

(b) with the temperature compensating system deactivated, compar­ing the
    uncompensated volume indicated or recorded to the actual delivered
    volume.

> The first test shall be performed with the auto­matic
> temperature-com­pensat­ing system operat­ing in the \"as found\"
> condition.
>
> On devices that indicate or record both the com­pensated and
> uncom­pen­sated volume for each delivery, the tests in (a) and (b) may
> be per­formed as a single test.
>
> (Amended 1987)
>
> **N.4.1.2. Repeatability Tests. ‑** Tests for repeatability should
> include a minimum of three consecutive test drafts of approximately
> the same size and be conducted under controlled conditions where
> variations in factors, such as temperature, pressure, and flow rate
> are reduced to the extent that they will not affect the results
> obtained.
>
> (Added 2001)
>
> **N.4.2. Special Tests.** - \"Special\" tests, to develop the
> operat­ing characteris­tics of a liquid-measuring device and any special
> elements and accessories attached to or associated with the device,
> shall be made as circumstances require. Any test except as set forth
> in N.4.1. shall be considered a special test.
>
> **N.4.2.1. Slow-Flow Meters.** - A \"special\" test shall be made at a
> flow rate:
>
> \(a\) not larger than twice the actual minimum flow rate, and
>
> \(b\) not smaller than the actual mini­mum flow rate of the
> installation.
>
> **N.4.2.2. Retail Motor-Fuel Devices.**

(a) Devices with a flow-rate capacity less than 100 L (25 gal) per
    minute shall have a \"special\" test performed at the slower of the
    follow­ing rates:

> \(1\) 19 L (5 gal) per minute, or
>
> \(2\) the minimum discharge rate marked on the device, or
>
> \(3\) the minimum discharge rate at which the device will deliver when
> equipped with an automatic discharge nozzle set at its slowest
> setting.

(b) Devices marked with a flow-rate capacity 100 L (25 gal) or more per
    minute, shall have a \"special\" test performed at the slowest of
    the follow­ing rates:

> \(1\) the minimum discharge rate marked on the device, or
>
> \(2\) the minimum discharge rate at which the device will deliver when
> equipped with an automatic dis­charge nozzle set at its slow­est
> setting.
>
> (Added 1984)
>
> **N.4.2.3. Other Retail Devices.** - \"Special\" tests of other retail
> devices shall be made at the slower of the following rates:

(a) 50 percent of the maximum discharge rate developed under the
    conditions of installa­tion, or

(b) the minimum discharge rate marked on the device.

> **N.4.2.4. Wholesale Devices.** - \"Special\" tests shall be made to
> develop the operating characteristics of a measuring system and any
> special associ­ated or attached elements and accessories. \"Special\"
> tests shall include a test at the slower of the following rates:

(a) 20 percent of the marked maximum discharge rate; or

(b) the minimum discharge rate marked on the device.

> **N.4.3. Money-Value Computation Tests.**
>
> **N.4.3.1. Lab­ora­tory Tests.** - When testing the device in the
> laboratory:

(a) compliance with paragraph S.1.6.5., Money­ Value Computations, shall
    be determined by using the cone gear as a ref­erence for the total
    quantity delivered;

(b) the indicated quantity shall agree with the cone gear repre­senta­tion
    with the index of the indicator within the width of the gradu­a­tion;
    and

(c) the maximum allowable variation of the indicated sales price shall
    be as shown in Table 1. (Amended 1984)

**N.4.3.2. Field Tests.** - In the conduct of field tests to determine
com­pliance with paragraph S.1.6.5., the maximum allowable variation in
the indicated sales price shall be as shown in Table 1.

(Added 1982; Amended 1984)

**N.5. Temperature Correc­tion on Wholesale Devices.** - Corrections
shall be made for any changes in volume resulting from the differences
in liquid temperatures between time of passage through the meter and
time of volumetric deter­mination in the prover. When adjustments are
necessary, appropriate pe­troleum measure­ment tables should be used.

(Amended 1974)

#### T. Toleran­ces

**T.1. Ap­plication to Underregistra­tion and to Over­reg­istration.** - The
tolerances hereinafter prescribed shall be applied to errors of
underregistra­tion and errors of overregistra­tion, whether or not a
device is equipped with an automatic tempera­ture compensator.

**T.2. Tolerance Values**. Maintenance, Acceptance, and Special Test
Tolerances shall be as shown in Table T.2.

+-------+----------------------------------+--------+---------+-------+
| ##### |                                  |        |         |       |
| ## Ta |                                  |        |         |       |
| ble T |                                  |        |         |       |
| .2. A |                                  |        |         |       |
| ccura |                                  |        |         |       |
| cy Cl |                                  |        |         |       |
| asses |                                  |        |         |       |
|  for  |                                  |        |         |       |
| Liqui |                                  |        |         |       |
| d Mea |                                  |        |         |       |
| surin |                                  |        |         |       |
| g Dev |                                  |        |         |       |
| ices  |                                  |        |         |       |
| Cover |                                  |        |         |       |
| ed in |                                  |        |         |       |
|       |                                  |        |         |       |
| ##    |                                  |        |         |       |
| ##### |                                  |        |         |       |
|  NIST |                                  |        |         |       |
|  Hand |                                  |        |         |       |
| book  |                                  |        |         |       |
| 44 Se |                                  |        |         |       |
| ction |                                  |        |         |       |
|  3.30 |                                  |        |         |       |
+-------+----------------------------------+--------+---------+-------+
| *     | **[Application]{.underline}**    | *      | **[Main | **[Sp |
| *[Acc |                                  | *[Acce | tenance | ecial |
| uracy |                                  | ptance | Tol     | Test  |
| Class |                                  | Tolera | erance] | Tole  |
| ]{.un |                                  | nce]{. | {.under | rance |
| derli |                                  | underl | line}** | ]{.un |
| ne}** |                                  | ine}** |         | derli |
|       |                                  |        |         | ne}** |
+-------+----------------------------------+--------+---------+-------+
| *     | **[Petroleum products including  | **[0.2 | **[0.3  | *     |
| *[0.3 | large capacity motor fuel        | %]{.   | %]      | *[0.5 |
| ]{.un | devices (flow rates over 115     | underl | {.under | %     |
| derli | L/min (30 gpm))\*\*, heated      | ine}** | line}** | ]{.un |
| ne}** | products at or greater than 50 C |        |         | derli |
|       | asphalt at or below temperatures |        |         | ne}** |
|       | 50 C, all other liquids not      |        |         |       |
|       | shown where the typical delivery |        |         |       |
|       | is over 200 L (50                |        |         |       |
|       | gal)]{.underline}**              |        |         |       |
+-------+----------------------------------+--------+---------+-------+
| **    | **[Asphalt at temperatures       | **[0.3 | **[0.3  | *     |
| [0.3A | greater than 50 C]{.underline}** | %]{.   | %]      | *[0.5 |
| ]{.un |                                  | underl | {.under | %     |
| derli |                                  | ine}** | line}** | ]{.un |
| ne}** |                                  |        |         | derli |
|       |                                  |        |         | ne}** |
+-------+----------------------------------+--------+---------+-------+
| **[   | **[Petroleum products delivered  | **[0.3 | **[0.5  | **    |
| 0.5\* | from small capacity (at 4 L/min  | %]{.   | %]      | [0.5% |
| ]{.un | (1 gpm) through 115 L/min (30    | underl | {.under | ]{.un |
| derli | gpm))\*\* motor-fuel devices,    | ine}** | line}** | derli |
| ne}** | agri-chemical liquids, and all   |        |         | ne}** |
|       | other applications not           |        |         |       |
|       | shown.]{.underline}**            |        |         |       |
+-------+----------------------------------+--------+---------+-------+
| *     | **[Petroleum products and other  | *      | **[1.0  | **[   |
| *[1.1 | normal liquids from devices with | *[0.75 | %]      | 1.25% |
| ]{.un | flow rates\*\* less than 1 gpm   | %]{.   | {.under | ]{.un |
| derli | and devices designed to deliver  | underl | line}** | derli |
| ne}** | less than one                    | ine}** |         | ne}** |
|       | gallon.]{.underline}**           |        |         |       |
+-------+----------------------------------+--------+---------+-------+
| **[   |                                  |        |         |       |
| \*The |                                  |        |         |       |
| m     |                                  |        |         |       |
| ainte |                                  |        |         |       |
| nance |                                  |        |         |       |
| toler |                                  |        |         |       |
| ances |                                  |        |         |       |
| on    |                                  |        |         |       |
| n     |                                  |        |         |       |
| ormal |                                  |        |         |       |
| and   |                                  |        |         |       |
| sp    |                                  |        |         |       |
| ecial |                                  |        |         |       |
| tests |                                  |        |         |       |
| for   |                                  |        |         |       |
| 5-g   |                                  |        |         |       |
| allon |                                  |        |         |       |
| and   |                                  |        |         |       |
| 10-g  |                                  |        |         |       |
| allon |                                  |        |         |       |
| test  |                                  |        |         |       |
| d     |                                  |        |         |       |
| rafts |                                  |        |         |       |
| are 6 |                                  |        |         |       |
| cubic |                                  |        |         |       |
| i     |                                  |        |         |       |
| nches |                                  |        |         |       |
| and   |                                  |        |         |       |
| 11    |                                  |        |         |       |
| cubic |                                  |        |         |       |
| in    |                                  |        |         |       |
| ches, |                                  |        |         |       |
| res   |                                  |        |         |       |
| pecti |                                  |        |         |       |
| vely. |                                  |        |         |       |
| Accep |                                  |        |         |       |
| tance |                                  |        |         |       |
| toler |                                  |        |         |       |
| ances |                                  |        |         |       |
| on    |                                  |        |         |       |
| n     |                                  |        |         |       |
| ormal |                                  |        |         |       |
| and   |                                  |        |         |       |
| sp    |                                  |        |         |       |
| ecial |                                  |        |         |       |
| tests |                                  |        |         |       |
| are 3 |                                  |        |         |       |
| cubic |                                  |        |         |       |
| i     |                                  |        |         |       |
| nches |                                  |        |         |       |
| and   |                                  |        |         |       |
| 5.5   |                                  |        |         |       |
| cubic |                                  |        |         |       |
| in    |                                  |        |         |       |
| ches. |                                  |        |         |       |
| ]{.un |                                  |        |         |       |
| derli |                                  |        |         |       |
| ne}** |                                  |        |         |       |
|       |                                  |        |         |       |
| **    |                                  |        |         |       |
| [\*\* |                                  |        |         |       |
| Flow  |                                  |        |         |       |
| rate  |                                  |        |         |       |
| r     |                                  |        |         |       |
| efers |                                  |        |         |       |
| to    |                                  |        |         |       |
| des   |                                  |        |         |       |
| igned |                                  |        |         |       |
| or    |                                  |        |         |       |
| m     |                                  |        |         |       |
| arked |                                  |        |         |       |
| ma    |                                  |        |         |       |
| ximum |                                  |        |         |       |
| flow  |                                  |        |         |       |
| rate. |                                  |        |         |       |
| ]{.un |                                  |        |         |       |
| derli |                                  |        |         |       |
| ne}** |                                  |        |         |       |
+-------+----------------------------------+--------+---------+-------+

(Added 2002)

**T.3 Repeatability.** - When multiple tests are conducted at
approximately the same flow rate and draft size, the range of the test
results for the flow rate shall not exceed 40 percent of the absolute
value of the maintenance tolerance and the results of each test shall be
within the applicable tolerance. This tolerance does not apply to the
test of the automatic temperature compensating system. See also N.4.1.2.

(Added 1992) (Amended 2001and 2002)

***T.4. Automatic Temperature Compensating Systems. -** The difference
between the meter error (expressed as a percentage) for results
determined with and without the automatic temperature compensating
system activated shall not exceed:*

> *(a) 0.2 percent for mechanical automatic temperature compensating
> systems; and*
>
> *(b) 0.1 percent for electronic automatic temperature compensating
> systems.*

*The delivered quantities for each test shall be approximately the same
size. The results of each test shall be within the applicable acceptance
or maintenance tolerance.*

*\[Nonretroactive as of January 1, 1988.\]*

(Added 1987) (Amended 1992, 1996 and 2002)

#### UR. User Require­ments

**UR.1. Selection Require­ments.**

> **UR.1.1. Dis­charge Hose.**
>
> **UR.1.1.1. Length.** - The length of the dis­charge hose on a retail
> motor-­fuel device:

(a) shall be measured from its housing or outlet of the discharge line
    to the inlet of the discharge nozzle;

(b) shall be measured with the hose fully extended if it is coiled or
    oth­erwise retained or connected inside a hous­ing; and

(c) shall not exceed 5.5 m (18 ft) unless it can be demonstrated that a
    longer hose is essential to permit deliveries to be made to
    re­ceiving vehicles or vessels.

> An unnecessarily remote location of a device shall not be accepted as
> justifi­cation for an abnormally long hose.
>
> (Amended 1972 and 1987)
>
> **UR.1.1.2. Marinas and Airports.**
>
> **UR.1.1.2.1. Length.** - The length of the discharge hose shall be as
> short as practicable, and shall not exceed 15 m (50 ft) unless it can
> be demonstrat­ed that a longer hose is essential.
>
> **UR.1.1.2.2. Protection.** - Discharge hoses exceeding 8 m (26 ft) in
> length shall be adequately protected from weather and other
> environ­mental factors when not in use.
>
> (Made retroactive 1974 and amend­ed 1984)

**UR.2. Installation Requirements.**

> **UR.2.1. Manu­fact­urer\'s Instructions.** - A device shall be
> installed in accordance with the manufactu­rer\'s instructions, and the
> installation shall be suffi­ciently secure and rigid to maintain this
> condition.
>
> (Added 1987)
>
> **UR.2.2. Discharge Rate.** - A device shall be installed so that the
> actual maximum discharge rate will not exceed the rated maximum
> discharge rate. Automat­ic means for flow regulation shall be
> incorporated in the instal­lation if necessary.
>
> **UR.2.3. Suction Head.** - A piston-type device shall be installed so
> that the total effective suction head will not be great enough to
> cause vapori­zation of the liquid being dispensed under the highest
> temperature and lowest barometric pressure likely to occur.
>
> **UR.2.4. Diversion of Liquid Flow.** - A motor-fuel device equipped
> with two delivery outlets used exclu­sively in the fueling of trucks
> shall be so installed that any diversion of flow to other than the
> receiving vehicle cannot be readily accomplis­hed and is readily
> apparent. Allowable deterrents in­clude, but are not limited to,
> physical barriers to adjacent drive­ways, visible valves, or lighting
> sys­tems that indicate which outlets are in operation, and explanatory
> signs.
>
> (Amended 1991)
>
> **UR.2.5. Product Storage Identi­fication.**

(a) The fill connection for any petroleum prod­uct storage tank or vessel
    supplying motor-fuel devices shall be permanently, plainly, and
    visibly marked as to product contained.

(b) When the fill connection device is marked by means of a color code,
    the color code key shall be conspicuously displayed at the place of
    business.

(Added 1975 and Amended 1976)

**UR.3. Use of Device.**

> **UR.3.1. Return of Indicat­ing and Recording Elements to Zero.** - On
> any dispenser used in making retail deliveries, the primary indicat­ing
> element, and re­cord­ing element if so equipped, shall be returned to
> zero before each delivery.
>
> Exceptions to this requirement are totalizers on key-lock-operated or
> other self-operated dispensers and the primary recording element if
> the device is equipped to record.
>
> **UR.3.2. Unit Price and Product Identity.**

(a) The following information shall be conspicu­ously displayed or posted
    on the face of a retail dispenser used in direct sale:

\(1\) except for dispensers used exclusively for fleet sales, other
price contract sales, and truck refueling (e.g., truck stop dispensers
used only to refuel trucks), all of the unit prices at which the product
is offered for sale; and

\(2\) in the case of a computing type or money-operated type, the unit
price at which the dis­penser is set to com­pute.

> Provided that the dispenser complies with S.1.6.4.1., it is not
> necessary that all the unit prices for all grades, brands, blends, or
> mixtures be simultaneously displayed or posted.

(b) The follow­ing information shall be con­spicu­ously displayed or posted
    on each side of a retail dispenser used in direct sale:

\(1\) the identity of the product in de­scrip­tive commercial terms, and

\(2\) the identity of the grade, brand, blend, or mixture that a
multi-­prod­uct dispenser is set to deliver.

> (Amended 1972, 1983, 1987, 1989, 1992, and 1993)
>
> **UR.3.3. Computing Device.**
>
> \(a\) Any computing device used in an appli­ca­tion where a product or
> grade is offered for sale at more than one unit price (excluding fleet
> sales and other price contract sales), shall be used only for sales
> for which the device computes and displays the sales price for the
> selected transaction.
>
> (Added 1989) (Amended 1992)
>
> (Became Retroactive 1999)
>
> \(b\) A truck stop dispenser used exclusively for refueling trucks is
> exempt from the requirements in (a) if all purchases of fuel are
> accompanied by a printed receipt of the transaction containing the
> applicable price per gallon, the total gallons delivered, and the
> total price of the sale.
>
> (Added 1993)
>
> \(c\) Unless a truck stop dispenser used exclusively for refueling
> trucks complies with S.1.6.4.1. (Display of Unit Price), the price
> posted on the dispenser and the price at which the dispenser is set to
> compute shall be the highest price for any transaction which may be
> conducted.
>
> (Added 1993)
>
> **UR.3.4. Printed Ticket.** - The total price, the total volume of the
> delivery, and the price per gallon or liter shall be shown, either
> printed or in clear hand script, on any printed ticket issued by a
> device and containing any one of these val­ues.
>
> (Amended 2001)
>
> **UR.3.5. Steps After Dispensing.** - After delivery to a customer
> from a retail motor-fuel device:

(a) the starting lever shall be returned to its shutoff position and the
    zero-set-back inter­lock engaged; and

(b) the discharge nozzle shall be returned to its designed hanging
    position unless the prima­ry indicating elements, and recording
    elements, if the de­vice is equipped and activated to record, have
    been returned to a definite zero indica­tion.

**UR.3.6. Temperature Compensation, Whole­sale.**

> **UR.3.6.1. Automatic.**
>
> **UR.3.6.1.1. When to be Used.** - If a device is equipped with a
> mechani­cal automatic temperature compen­sator, it shall be con­nected,
> opera­ble, and in use at all times. An electronic or mechanical
> automatic tempera­ture compensating system may not be removed, nor may
> a compensated device be replaced with an uncom­pensated device, without
> the written approval of the responsible weights and measures
> jurisdic­tion.
>
> \[Note: This requirement does not specify the method of sale for
> prod­uct measured through a meter.\]
>
> (Amended 1989)
>
> **UR.3.6.1.2. Invoices.**

(a) A written invoice based on a reading of a device that is equipped
    with an automatic tempera­ture compen­sator shall show that the volume
    delivered has been adjusted to the volume at 15 C (60 F).

(b) The invoice issued from an electronic wholesale device equipped with
    an automatic temperature compensating system shall also
    indicate: (1) the API gravity, specific gravity or coefficient of
    expansion for the product; (2) product temperature; and (3) gross
    reading.

> (Amended 1987)
>
> **UR.3.6.2. Nonautomatic.**
>
> **UR.3.6.2.1. Temper­ature Determi­nation.** - If the volume of the
> prod­uct delivered is adjusted to the vol­ume at 15 C (60 F), the
> product tem­pe­rature shall be taken during the delivery in:
>
> \(a\) the liquid chamber of the meter, or
>
> \(b\) the meter inlet or discharge line adjacent to the meter, or

\(c\) the com­partment of the receiving vehicle at the time it is loaded.

> **UR.3.6.2.2. In­voices.** - The acco­mpa­nying invoice shall indicate
> that the volume of the product has been adjusted for temperature
> variations to a volume at 15 C (60 F) and shall also state the product
> temperature used in making the adjustment.

**Liquid-Measuring Device Code Index**

Acceptance 16, 17

Adjustable element 9

Advancement 4, 11

Agreement 7, 8

Agri-chemical 3, 11, 16

Antidrain means 12

Automatic 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 19

Automatic temperature compensating systems 11, 14, 17

Automatic temperature compensation 11

Auxiliary elements 7

Blend 6, 18

Clear interval 4

Clearance 5

Computing device 6, 7, 19

Directional flow valves 9

Discharge hose 12, 17

Discharge lines 11

Discharge rate 12, 13, 14, 15, 17

Discharge rates 13

Dry hose 12

Fleet sales 6, 7, 8, 18, 19

Grade 6, 7, 18, 19

Graduations 4, 5, 8, 12

Gravity-discharge unit 12

Index of an indicator 4, 5

Indicating element 3, 4, 5, 10, 13, 18

Indicators 4

Installation requirements 17

Interlock 10, 19

Invoices 19, 20

Key-lock 5, 18

Lubricant devices 8, 11, 14

Maintenance 16,17

Marking requirements 12

Mass 1, 3

Mass flow meters 1, 3

Measuring elements 8

Money values-mathematical agreement 8

Money-value computation 6, 15

Money-value computations 6

Money-value divisions 6, 7

Motor-fuel device 3, 10, 15, 16, 17, 18, 19

Nonautomatic 20

Normal tests 14

Operating requirements 5, 8

Parallax 5

Power loss 5

Price contract sales 6, 8, 18, 19

Primary indicating element 3, 5, 13, 18, 19

Printed ticket 19

Product identity 5, 6, 8, 18

Pump-discharge unit 12

Quantity 5, 6, 7, 8, 13, 14, 15

Recording element 3, 4, 5, 8, 10, 13, 18, 19

Repeatability 14, 16

Retail devices 4, 5, 13, 14, 15

Retail motor-fuel device 3, 10, 15, 17, 19

Retail motor-fuel dispensers 13

Seal 9, 10, 11, 12

Sealing 9, 10, 11

Security 9, 11, 12

Slow flow meters 5, 13

Special tests 14, 16

Stop mechanism 9

Temperature correction 16

Temperature determination 11, 20

Test drafts 13, 14, 16

Tolerances 9, 16

Total price 7, 19

Totalizers 13, 18

Truck refueling 6, 7, 12, 18

Unit price 5, 6, 7, 8, 18, 19

User information 5

Valves 9, 11, 12, 18

Vapor elimination 8

Wet-hose 12

Wholesale devices 3, 4, 8, 11, 12, 14, 15, 16

Zero-set-back interlock 10, 19