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Table of Contents

Page

Section 3.38. Carbon Dioxide Liquid-Measuring Devices............................................. 3-127

A. Application ................................................................................................................................................ 3-127

A.1. General..............................................................................................................................................3-127

A.2. Exceptions.........................................................................................................................................3-127

A.3. Additional Code Requirements.........................................................................................................3-127

A.4. Type Evaluation................................................................................................................................3-127

S. Specifications............................................................................................................................................. 3-127

S.1. Design of Indicating and Recording Elements and of Recorded Representations. ...........................3-127

S.1.1. Primary Elements................................................................................................................3-127

S.1.2. Graduations.........................................................................................................................3-128

S.1.3. Indicators. ...........................................................................................................................3-128

S.1.4. Computing-Type Devices. ..................................................................................................3-129

S.2. Design of Measuring Elements.........................................................................................................3-129

S.2.1. Air/Vapor Elimination .......................................................................................................3-129

S.2.2. Reverse Flow Measurement................................................................................................3-129

S.2.3. Maintenance of Liquid State...............................................................................................3-129

S.2.4. Automatic Temperature or Density Compensation.............................................................3-129

S.2.5. Provision for Sealing...........................................................................................................3-129

S.3. Design of Discharge Lines and Discharge Line Valves....................................................................3-130

S.3.1. Diversion of Measured Liquid. ...........................................................................................3-130

S.3.2. Discharge Hose...................................................................................................................3-130

S.4. Marking Requirements......................................................................................................................3-131

S.4.1. Limitation of Use. ...............................................................................................................3-131

S.4.2. Discharge Rates. .................................................................................................................3-131

N. Notes........................................................................................................................................................... 3-131

N.1. Test Liquid........................................................................................................................................3-131

N.2. Vaporization and Volume Change....................................................................................................3-131

N.3. Test Drafts.........................................................................................................................................3-131

N.3.1. Gravimetric Test. ................................................................................................................3-131

N.3.2. Transfer Standard Test........................................................................................................3-131

N.3.3. Volumetric Prover Test Drafts............................................................................................3-131

N.4. Testing Procedures............................................................................................................................3-131

N.4.1. Normal Tests.......................................................................................................................3-131

N.4.2. Special Tests. ......................................................................................................................3-131

N.4.3. Density................................................................................................................................3-131

N.4.4. Automatic Temperature or Density Compensation.............................................................3-132

N.4.5. Repeatability Tests..............................................................................................................3-138

T. Tolerances.................................................................................................................................................. 3-138

T.1. Application........................................................................................................................................3-138

T.1.1. To Underregistration and to Overregistration.....................................................................3-138

T.2. Tolerance Values. .............................................................................................................................3-138

T.2.1. Repeatability. ......................................................................................................................3-138

T.3. On Tests Using Transfer Standards. .................................................................................................3-138
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UR. User Requirements ................................................................................................................................... 3-138

UR.1. Installation Requirements. ................................................................................................................3-138

UR.1.1. Discharge Rate....................................................................................................................3-138

UR.1.2. Length of Discharge Hose. .................................................................................................3-139

UR.1.3. Maintenance of Liquid State...............................................................................................3-139

UR.2. Use Requirements. ............................................................................................................................3-139

UR.2.1. Return of Indicating and Recording Elements to Zero. ......................................................3-139

UR.2.2. Condition of Discharge System. .........................................................................................3-139

UR.2.3. Vapor Equalization Line.....................................................................................................3-139

UR.2.4. Temperature or Density Compensation. .............................................................................3-139

UR.2.5. Ticket in Printing Device....................................................................................................3-139

UR.2.6. Sale by Weight....................................................................................................................3-139
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Section 3.38. Carbon Dioxide Liquid-Measuring Devices 

A. Application

A.1. General. – This code applies to liquid-measuring devices used for the measurement of liquid carbon dioxide.

A.2. Exceptions. – This code does not apply to devices used solely for dispensing a product in connection with 

operations in which the amount dispensed does not affect customer charges.

A.3. Additional Code Requirements. – In addition to the requirements of this code, Carbon Dioxide LiquidMeasuring Devices shall meet the requirements of Section 1.10. General Code.

A.4. Type Evaluation. – The National Type Evaluation Program will accept for type evaluation only those devices

that comply with all requirements of this code.

(Added 1998)

S. Specifications

S.1. Design of Indicating and Recording Elements and of Recorded Representations.

S.1.1. Primary Elements.

S.1.1.1. General. – A device shall be equipped with a primary indicating element and may also be 

equipped with a primary recording element.

S.1.1.2. Units. – A device shall indicate and record, if equipped to record, its deliveries in terms of pounds 

or kilograms or decimal subdivisions or multiples thereof.

S.1.1.3. 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) for small delivery devices:

(1) 1 kilogram; or

(2) 1 pound

(b) for large delivery devices:

(1) 10 kilograms; or

(2) 10 pounds

S.1.1.4. Advancement of Indicating and Recording Elements. – Primary indicating and recording 

elements shall be susceptible to advancement only by the normal operation of the device. However, a device 

may be cleared by advancing its elements to zero, but only if:

(a) the advancing movement, once started, cannot be stopped until zero is reached; or

(b) in the case of indicating elements only, such elements are automatically obscured until the elements 

reach the correct zero position.
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S.1.1.5. Return to Zero. – Primary indicating and recording elements shall be readily returnable to a 

definite zero indication. Means shall be provided to prevent the return of primary indicating elements and of 

primary recording elements beyond their correct zero position.

S.1.2. Graduations.

S.1.2.1. Length. – Graduations shall be so varied in length that they may be conveniently read.

S.1.2.2. Width. – In any series of graduations, the width of a graduation shall in no case be greater than 

the width of the minimum clear interval between graduations. The width of main graduations shall be not 

more than 50 % greater than the width of subordinate graduations. Graduations shall in no case be less than 

0.2 mm (0.008 in) in width.

S.1.2.3. Clear Interval Between Graduations. – The clear interval 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 relative movement between the graduations at the end of the indicator; or

(b) if the indicator is continuous, at the point of widest separation of the graduations.

(Also see S.1.3.6. Travel of Indicator.)

S.1.3. Indicators.

S.1.3.1. Symmetry. – The index of an indicator shall be of the same shape as the graduations at least 

throughout that portion of its length associated with the graduations.

S.1.3.2. Length. – The index of an indicator shall reach to the finest graduations with which it is used, 

unless the indicator and the graduations are in the same plane, in which case the distance between the end 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.1.3.3. Width. – The width of the index of the indicator in relation to the series of graduations with which 

it is used shall be not greater than:

(a) the width of the narrowest graduation;* and

[*Nonretroactive as of January 1, 2002]

(Amended 2001)

(b) the width of the minimum clear interval between graduations.

When the index of an indicator extends along the entire length of a graduation, that portion of the index of 

the indicator that may be brought into coincidence with the graduation shall be of the same width throughout 

the length of the index that coincides with the graduation.

S.1.3.4. Clearance. – The clearance between the index of an indicator and the graduations shall in no case 

be more than 1.5 mm (0.06 in).

S.1.3.5. Parallax. – Parallax effects shall be reduced to the practicable minimum.

S.1.3.6. Travel of Indicator. – If the most sensitive element of the primary indicating element utilizes an 

indicator and graduations, the relative movement of these parts corresponding to the smallest indicated value 

shall be no less than 5 mm (0.20 in).
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S.1.4. Computing-Type Devices.

S.1.4.1. Printed Ticket. – Any printed ticket issued by a device of the computing type on which there is 

printed the total computed price shall have printed clearly thereon also the total quantity of the delivery and 

the price per unit.

S.1.4.2. Money-Value Computations. – Money-value computations shall be of the full-computing type 

in which the money-value at a single unit price, or at each of a series of unit prices, shall be computed for 

every delivery within either the range of measurement of the device or the range of the computing elements, 

whichever is less.

The total price shall be computed on the basis of the quantity indicated when the value of the smallest division 

indicated is equal to or less than the value specified in S.1.1.3. Value of Smallest Unit.

S.1.4.3. 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 1 cent of money-value.

S.2. Design of Measuring Elements.

S.2.1. Air/Vapor Elimination. – A measuring system shall be equipped with an effective air/vapor eliminator 

or other automatic means to prevent the passage of air/vapor through the meter. Vent lines from the air/vapor 

eliminator shall be made of appropriate non-collapsible material. (Also see Section T. Tolerances.)

(Amended 2016 and 2018)

S.2.2. Reverse Flow Measurement. – Effective means, automatic in operation, shall be installed to prevent 

reverse flow measurement.

S.2.3. Maintenance of Liquid State. – A device shall be so designed that the product being measured will 

remain in a liquid state during passage through the device.

S.2.4. Automatic Temperature or Density Compensation. – A volumetric device shall be equipped with 

automatic means for adjusting the indication and recorded representation of the measured quantity of the product 

to indicate or record the quantity of the product measured in terms of pounds.

S.2.5. Provision for Sealing. – For devices and systems in which the configuration or calibration parameters 

can be changed by use of a removable digital storage device, security shall be provided for those parameters as 

specified in G-S.8.2. Devices and Systems Adjusted Using Removable Digital Storage Devices. For parameters 

adjusted using other means, the following applies.

Adequate provision shall be made for an approved means of security (e.g., data change audit trail) or for 

physically applying a security seal in such a manner that requires the security seal to be broken before an 

adjustment or interchange can be made of:

(a) any measuring or indicating element;

(b) any adjustable element for controlling delivery rate when such rate tends to affect the accuracy of 

deliveries;

(c) any automatic temperature or density compensating system; and

(d) any metrological parameter that will affect the metrological integrity of the device or system.
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When applicable any adjusting mechanism shall be readily accessible for purposes of affixing a security seal.

Audit trails shall use the format set forth in Table S.2.5. Provision for Sealing.*

[*Nonretroactive as of January 1, 1995]

(Amended 2006 and 2019)

Table S.2.5. 

Categories of Device and Methods of Sealing

Categories of Device Methods of Sealing

Category 1: No remote configuration capability. Seal by physical seal or two event counters: one for 

calibration parameters and one for configuration 

parameters.

Category 2: Remote configuration capability, but 

access is controlled by physical hardware.

The device shall clearly indicate that it is in the remote 

configuration mode and record such message if capable 

of printing in this mode or shall not operate while in this 

mode.

The hardware enabling access for remote 

communication must be on-site. The hardware must be 

sealed using a physical seal or an event counter for 

calibration parameters and an event counter for 

configuration parameters. The event counters may be 

located either at the individual measuring device or at 

the system controller; however, an adequate number of 

counters must be provided to monitor the calibration and 

configuration parameters of the individual devices at a 

location. If the counters are located in the system 

controller rather than at the individual device, means 

must be provided to generate a hard copy of the 

information through an on-site device.

Category 3: Remote configuration capability access 

may be unlimited or controlled through a software 

switch (e.g., password).

The device shall clearly indicate that it is in the remote 

configuration mode and record such message if capable 

of printing in this mode or shall not operate while in this 

mode.

An event logger is required in the device; it must include 

an event counter (000 to 999), the parameter ID, the date 

and time of the change, and the new value of the 

parameter. A printed copy of the information must be 

available on demand through the device or through 

another on-site device. The information may also be 

available electronically. The event logger shall have a 

capacity to retain records equal to 10 times the number 

of sealable parameters in the device, but not more than 

1000 records are required. (Note: Does not require 

1000 changes to be stored for each parameter.)

[Nonretroactive as of January 1, 1995]

(Table Added 2006) (Amended 2016)

S.3. Design of Discharge Lines and Discharge Line 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 device or the discharge line therefrom, except that a manually 

controlled outlet that may be opened for purging or draining the measuring system shall be permitted. Effective 

means shall be provided to prevent the passage of liquid through any such outlet during normal operation of the 

device and to indicate clearly and unmistakably when the valve controls are so set as to permit passage of liquid 

through such outlet.

S.3.2. Discharge Hose. – The discharge hose of a measuring system shall be of a wet hose type with a shutoff 

valve at its outlet end.
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S.4. Marking Requirements.

S.4.1. Limitation of Use. – If a measuring system is intended to measure accurately only liquids having 

particular properties, or to measure accurately only under specific installation or operating conditions, or to 

measure accurately only when used in conjunction with specific accessory equipment, these limitations shall be 

clearly and permanently marked on the device.

S.4.2. Discharge Rates. – A meter shall be marked to show its designed maximum and minimum discharge 

rates. The marked minimum discharge rate shall not exceed 20 % of the marked maximum discharge rate.

Note: Also see example in Section 3.30. Liquid-Measuring Devices Code, paragraph S.4.4.1. Discharge Rates.

(Note Added 2003)

N. Notes

N.1. Test Liquid. – The test liquid shall be carbon dioxide in a compressed liquid state.

N.2. Vaporization and Volume Change. – Care shall be exercised to reduce vaporization and volume changes to 

a minimum. When testing by weight, the weigh tank and transfer systems shall be pre-cooled to liquid temperature 

prior to the start of the test to avoid the venting of vapor from the vessel being weighed.

N.3. Test Drafts.

N.3.1. Gravimetric Test. – Weight test drafts shall be equal to at least the amount delivered by the device in 

2 minutes at its maximum discharge rate.

N.3.2. Transfer Standard Test. – When comparing a meter with a calibrated transfer standard, the test draft 

shall be equal to at least the amount delivered by the device in two minutes at its maximum discharge rate.

N.3.3. Volumetric Prover Test Drafts. – Test drafts shall be equal to at least the amount delivered in 

one minute at its normal discharge rate.

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.

N.4.2. Special Tests. – Any test except as set forth in N.4.1. Normal Tests shall be considered a special test. 

Tests shall be conducted, if possible, to evaluate any special elements or accessories attached to or associated 

with the device. A device shall be tested at a minimum discharge rate of:

(a) not less than the marked minimum discharge rate or 20 % of the maximum rated discharge rate of the 

device, whichever is less; or

(b) the lowest discharge rate practicable under the conditions of installation.

“Special” tests may be conducted to develop any characteristics of the device anticipated under the conditions of 

installation.

N.4.3. Density. – Temperature and pressure of the metered test liquid shall be measured during the test for the 

determination of density or volume correction when applicable. The appropriate correction values shall apply as 

specified in Table N.4.4.
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N.4.4. Automatic Temperature or Density Compensation. – If a device is equipped with an automatic 

temperature or density compensator, the compensator shall be tested by comparing the quantity indicated or 

recorded by the device (with the compensator connected and operating) with the actual delivered quantity. The 

appropriate correction values shall apply as specified in Table N.4.4.

Table N.4.4.

Automatic Temperature or Density Compensation

Temp °F

Pressure Liquid Density Vapor Density Vapor 

PSIA PSIG lb/gal (lb-oz)/gal lb/cu ft lb/gal Displacement %

− 30.00 177.89 163.19 9.127 9 - 2.0 1.989 0.266 2.9

− 29.75 178.75 164.05 9.122 9 - 2.0 1.999 0.267 2.9

− 29.50 179.62 164.92 9.117 9 - 1.9 2.008 0.268 2.9

− 29.25 180.49 165.79 9.113 9 - 1.8 2.018 0.270 3.0

− 29.00 181.36 166.67 9.108 9 - 1.7 2.028 0.271 3.0

− 28.75 182.24 167.54 9.103 9 - 1.7 2.038 0.272 3.0

− 28.50 183.12 168.42 9.098 9 - 1.6 2.048 0.274 3.0

− 28.25 184.00 169.31 9.094 9 - 1.5 2.058 0.275 3.0

− 28.00 184.89 170.19 9.089 9 - 1.4 2.067 0.276 3.0

− 27.75 185.78 171.08 9.084 9 - 1.3 2.077 0.278 3.1

− 27.50 186.67 171.98 9.080 9 - 1.3 2.087 0.279 3.1

− 27.25 187.57 172.87 9.075 9 - 1.2 2.098 0.280 3.1

− 27.00 188.47 173.77 9.070 9 - 1.1 2.108 0.282 3.1

− 26.75 189.37 174.67 9.065 9 - 1.0 2.118 0.283 3.1

− 26.50 190.28 175.58 9.061 9 - 1.0 2.128 0.284 3.1

− 26.25 191.18 176.49 9.056 9 - 0.9 2.138 0.286 3.2

− 26.00 192.10 177.40 9.051 9 - 0.8 2.148 0.287 3.2

− 25.75 193.01 178.32 9.046 9 - 0.7 2.159 0.289 3.2

− 25.50 193.93 179.23 9.041 9 - 0.7 2.169 0.290 3.2

− 25.25 194.85 180.16 9.037 9 - 0.6 2.179 0.291 3.2

− 25.00 195.78 181.08 9.032 9 - 0.5 2.190 0.293 3.2

− 24.75 196.70 182.01 9.027 9 - 0.4 2.200 0.294 3.3

− 24.50 197.64 182.94 9.022 9 - 0.4 2.211 0.296 3.3

− 24.25 198.57 183.87 9.017 9 - 0.3 2.221 0.297 3.3

− 24.00 199.51 184.81 9.013 9 - 0.2 2.232 0.298 3.3

− 23.75 200.45 185.75 9.008 9 - 0.1 2.243 0.300 3.3

− 23.50 201.39 186.70 9.003 9 - 0.0 2.253 0.301 3.3

− 23.25 202.34 187.64 8.998 9 - 0.0 2.264 0.303 3.4

− 23.00 203.29 188.60 8.993 8 - 15.9 2.275 0.304 3.4

− 22.75 204.25 189.55 8.989 8 - 15.8 2.286 0.306 3.4

− 22.50 205.20 190.51 8.984 8 - 15.7 2.296 0.307 3.4

− 22.25 206.16 191.47 8.979 8 - 15.7 2.307 0.308 3.4
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Table N.4.4.

Automatic Temperature or Density Compensation

Temp °F

Pressure Liquid Density Vapor Density Vapor 

PSIA PSIG lb/gal (lb-oz)/gal lb/cu ft lb/gal Displacement %

− 22.00 207.13 192.43 8.974 8 - 15.6 2.318 0.310 3.5

− 21.75 208.09 193.40 8.969 8 - 15.5 2.329 0.311 3.5

− 21.50 209.06 194.37 8.964 8 - 15.4 2.340 0.313 3.5

− 21.25 210.04 195.34 8.959 8 - 15.4 2.351 0.314 3.5

− 21.00 211.02 196.32 8.955 8 - 15.3 2.362 0.316 3.5

− 20.75 212.00 197.30 8.950 8 - 15.2 2.374 0.317 3.5

− 20.50 212.98 198.28 8.945 8 - 15.1 2.385 0.319 3.6

− 20.25 213.97 199.27 8.940 8 - 15.0 2.396 0.320 3.6

− 20.00 214.96 200.26 8.935 8 - 15.0 2.407 0.322 3.6

− 19.75 215.95 201.26 8.930 8 - 14.9 2.419 0.323 3.6

− 19.50 216.95 202.25 8.925 8 - 14.8 2.430 0.325 3.6

− 19.25 217.95 203.25 8.920 8 - 14.7 2.441 0.326 3.7

− 19.00 218.95 204.26 8.915 8 - 14.6 2.453 0.328 3.7

− 18.75 219.96 205.27 8.911 8 - 14.6 2.464 0.329 3.7

− 18.50 220.97 206.28 8.906 8 - 14.5 2.476 0.331 3.7

− 18.25 221.99 207.29 8.901 8 - 14.4 2.488 0.333 3.7

− 18.00 223.01 208.31 8.896 8 - 14.3 2.499 0.334 3.8

− 17.75 224.03 209.33 8.891 8 - 14.3 2.511 0.336 3.8

− 17.50 225.05 210.36 8.886 8 - 14.2 2.523 0.337 3.8

− 17.25 226.08 211.38 8.881 8 - 14.1 2.534 0.339 3.8

− 17.00 227.11 212.42 8.876 8 - 14.0 2.546 0.340 3.8

− 16.75 228.15 213.45 8.871 8 - 13.9 2.558 0.342 3.9

− 16.50 229.18 214.49 8.866 8 - 13.9 2.570 0.344 3.9

− 16.25 230.23 215.53 8.861 8 - 13.8 2.582 0.345 3.9

− 16.00 231.27 216.58 8.856 8 - 13.7 2.594 0.347 3.9

− 15.75 232.32 217.62 8.851 8 - 13.6 2.606 0.348 3.9

− 15.50 233.37 218.68 8.846 8 - 13.5 2.618 0.350 4.0

− 15.25 234.43 219.73 8.841 8 - 13.5 2.630 0.352 4.0

− 15.00 235.49 220.79 8.836 8 - 13.4 2.643 0.353 4.0

− 14.75 236.55 221.86 8.831 8 - 13.3 2.655 0.355 4.0

− 14.50 237.62 222.92 8.826 8 - 13.2 2.667 0.357 4.0

− 14.25 238.69 223.99 8.821 8 - 13.1 2.680 0.358 4.1

− 14.00 239.76 225.07 8.816 8 - 13.1 2.692 0.360 4.1

− 13.75 240.84 226.14 8.811 8 - 13.0 2.704 0.362 4.1

− 13.50 241.92 227.22 8.806 8 - 12.9 2.717 0.363 4.1
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Table N.4.4.

Automatic Temperature or Density Compensation

Temp °F

Pressure Liquid Density Vapor Density Vapor 

PSIA PSIG lb/gal (lb-oz)/gal lb/cu ft lb/gal Displacement %

− 13.25 243.00 228.31 8.801 8 - 12.8 2.729 0.365 4.1

− 13.00 244.09 229.39 8.796 8 - 12.7 2.742 0.367 4.2

− 12.75 245.18 230.49 8.791 8 - 12.7 2.755 0.368 4.2

− 12.50 246.28 231.58 8.786 8 - 12.6 2.767 0.370 4.2

− 12.25 247.37 232.68 8.781 8 - 12.5 2.780 0.372 4.2

− 12.00 248.48 233.78 8.776 8 - 12.4 2.793 0.373 4.3

− 11.75 249.58 234.89 8.771 8 - 12.3 2.806 0.375 4.3

− 11.50 250.69 236.00 8.765 8 - 12.2 2.819 0.377 4.3

− 11.25 251.80 237.11 8.760 8 - 12.2 2.832 0.379 4.3

− 11.00 252.92 238.22 8.755 8 - 12.1 2.845 0.380 4.3

− 10.75 254.04 239.34 8.750 8 - 12.0 2.858 0.382 4.4

− 10.50 255.16 240.47 8.745 8 - 11.9 2.871 0.384 4.4

− 10.25 256.29 241.60 8.740 8 - 11.8 2.884 0.386 4.4

− 10.00 257.42 242.73 8.735 8 - 11.8 2.897 0.387 4.4

− 9.75 258.56 243.86 8.730 8 - 11.7 2.911 0.389 4.5

− 9.50 259.70 245.00 8.725 8 - 11.6 2.924 0.391 4.5

− 9.25 260.84 246.14 8.719 8 - 11.5 2.937 0.393 4.5

− 9.00 261.98 247.29 8.714 8 - 11.4 2.951 0.394 4.5

− 8.75 263.13 248.44 8.709 8 - 11.3 2.964 0.396 4.5

− 8.50 264.29 249.59 8.704 8 - 11.3 2.978 0.398 4.6

− 8.25 265.44 250.75 8.699 8 - 11.2 2.991 0.400 4.6

− 8.00 266.60 251.91 8.694 8 - 11.1 3.005 0.402 4.6

− 7.75 267.77 253.07 8.688 8 - 11.0 3.019 0.404 4.6

− 7.50 268.93 254.24 8.683 8 - 10.9 3.032 0.405 4.7

− 7.25 270.11 255.41 8.678 8 - 10.8 3.046 0.407 4.7

− 7.00 271.28 256.59 8.673 8 - 10.8 3.060 0.409 4.7

− 6.75 272.46 257.76 8.668 8 - 10.7 3.074 0.411 4.7

− 6.50 273.64 258.95 8.662 8 - 10.6 3.088 0.413 4.8

− 6.25 274.83 260.13 8.657 8 - 10.5 3.102 0.415 4.8

− 6.00 276.02 261.32 8.652 8 - 10.4 3.116 0.417 4.8

− 5.75 277.21 262.52 8.647 8 - 10.3 3.130 0.418 4.8

− 5.50 278.41 263.72 8.641 8 - 10.3 3.144 0.420 4.9

− 5.25 279.61 264.92 8.636 8 - 10.2 3.159 0.422 4.9

− 5.00 280.82 266.12 8.631 8 - 10.1 3.173 0.424 4.9

− 4.75 282.03 267.33 8.626 8 - 10.0 3.187 0.426 4.9
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Table N.4.4.

Automatic Temperature or Density Compensation

Temp °F

Pressure Liquid Density Vapor Density Vapor 

PSIA PSIG lb/gal (lb-oz)/gal lb/cu ft lb/gal Displacement %

− 4.50 283.24 268.55 8.620 8 - 9.9 3.202 0.428 5.0

− 4.25 284.46 269.76 8.615 8 - 9.8 3.216 0.430 5.0

− 4.00 285.68 270.98 8.610 8 - 9.8 3.231 0.432 5.0

− 3.75 286.90 272.21 8.604 8 - 9.7 3.245 0.434 5.0

− 3.50 288.13 273.44 8.599 8 - 9.6 3.260 0.436 5.1

− 3.25 289.37 274.67 8.594 8 - 9.5 3.275 0.438 5.1

− 3.00 290.60 275.91 8.589 8 - 9.4 3.289 0.440 5.1

− 2.75 291.84 277.15 8.583 8 - 9.3 3.304 0.442 5.1

− 2.50 293.09 278.39 8.578 8 - 9.2 3.319 0.444 5.2

− 2.25 294.33 279.64 8.573 8 - 9.2 3.334 0.446 5.2

− 2.00 295.58 280.89 8.567 8 - 9.1 3.349 0.448 5.2

− 1.75 296.84 282.14 8.562 8 - 9.0 3.364 0.450 5.3

− 1.50 298.10 283.40 8.556 8 - 8.9 3.379 0.452 5.3

− 1.25 299.36 284.67 8.551 8 - 8.8 3.395 0.454 5.3

− 1.00 300.63 285.93 8.546 8 - 8.7 3.410 0.456 5.3

− 0.75 301.90 287.21 8.540 8 - 8.6 3.425 0.458 5.4

− 0.50 303.18 288.48 8.535 8 - 8.6 3.440 0.460 5.4

− 0.25 304.46 289.76 8.530 8 - 8.5 3.456 0.462 5.4

0.00 305.74 291.74 8.524 8 - 8.4 3.471 0.464 5.4

0.25 307.03 292.33 8.519 8 - 8.3 3.487 0.466 5.5

0.50 308.32 293.62 8.513 8 - 8.2 3.503 0.468 5.5

0.75 309.61 294.92 8.508 8 - 8.1 3.518 0.470 5.5

1.00 310.91 296.21 8.502 8 - 8.0 3.534 0.472 5.6

1.25 312.21 297.52 8.497 8 - 8.0 3.550 0.475 5.6

1.50 313.52 298.82 8.491 8 - 7.9 3.566 0.477 5.6

1.75 314.83 300.13 8.486 8 - 7.8 3.582 0.479 5.6

2.00 316.15 301.45 8.480 8 - 7.7 3.598 0.481 5.7

2.25 317.46 302.77 8.475 8 - 7.6 3.614 0.483 5.7

2.50 318.79 304.09 8.469 8 - 7.5 3.630 0.485 5.7

2.75 320.11 305.42 8.464 8 - 7.4 3.646 0.487 5.8

3.00 321.45 306.75 8.458 8 - 7.3 3.662 0.490 5.8

3.25 322.78 308.08 8.453 8 - 7.2 3.679 0.492 5.8

3.50 324.12 309.42 8.447 8 - 7.2 3.695 0.494 5.8

3.75 325.46 310.77 8.442 8 - 7.1 3.712 0.496 5.9

4.00 326.81 312.11 8.436 8 - 7.0 3.728 0.498 5.9
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Table N.4.4.

Automatic Temperature or Density Compensation

Temp °F

Pressure Liquid Density Vapor Density Vapor 

PSIA PSIG lb/gal (lb-oz)/gal lb/cu ft lb/gal Displacement %

4.25 328.16 313.46 8.431 8 - 6.9 3.745 0.501 5.9

4.50 329.52 314.82 8.425 8 - 6.8 3.761 0.503 6.0

4.75 330.88 316.18 8.420 8 - 6.7 3.778 0.505 6.0

5.00 332.24 317.54 8.414 8 - 6.6 3.795 0.507 6.0

5.25 333.61 318.91 8.408 8 - 6.5 3.812 0.510 6.1

5.50 334.98 320.28 8.403 8 - 6.4 3.829 0.512 6.1

5.75 336.35 321.66 8.397 8 - 6.4 3.846 0.514 6.1

6.00 337.73 323.04 8.392 8 - 6.3 3.863 0.516 6.2

6.25 339.12 324.42 8.386 8 - 6.2 3.880 0.519 6.2

6.50 340.51 325.81 8.380 8 - 6.1 3.897 0.521 6.2

6.75 341.90 327.20 8.375 8 - 6.0 3.915 0.523 6.3

7.00 343.30 328.60 8.369 8 - 5.9 3.932 0.526 6.3

7.25 344.70 330.00 8.363 8 - 5.8 3.949 0.528 6.3

7.50 346.10 331.41 8.358 8 - 5.7 3.967 0.530 6.3

7.75 347.51 332.82 8.352 8 - 5.6 3.984 0.533 6.4

8.00 348.92 334.23 8.346 8 - 5.5 4.002 0.535 6.4

8.25 350.34 335.65 8.341 8 - 5.4 4.020 0.537 6.4

8.50 351.76 337.07 8.335 8 - 5.4 4.038 0.540 6.5

8.75 353.19 338.49 8.335 8 - 5.4 4.038 0.540 6.5

9.00 354.62 339.92 8.323 8 - 5.2 4.073 0.545 6.5

9.25 356.06 341.36 8.318 8 - 5.1 4.091 0.547 6.6

9.50 357.49 342.80 8.312 8 - 5.0 4.110 0.549 6.6

9.75 358.94 344.24 8.306 8 - 4.9 4.128 0.552 6.6

10.00 360.38 345.69 8.300 8 - 4.8 4.146 0.554 6.7

10.25 361.84 347.14 8.295 8 - 4.7 4.164 0.557 6.7

10.50 363.29 348.60 8.289 8 - 4.6 4.183 0.559 6.7

10.75 364.75 350.06 8.283 8 - 4.5 4.201 0.562 6.8

11.00 366.22 351.52 8.277 8 - 4.4 4.220 0.564 6.8

11.25 367.68 352.99 8.271 8 - 4.3 4.238 0.567 6.8

11.50 369.16 354.46 8.266 8 - 4.2 4.257 0.569 6.9

11.75 370.64 355.94 8.260 8 - 4.2 4.276 0.572 6.9

12.00 372.12 357.42 8.254 8 - 4.1 4.295 0.574 7.0

12.25 373.60 358.91 8.248 8 - 4.0 4.314 0.577 7.0

12.50 375.09 360.40 8.242 8 - 3.9 4.333 0.579 7.0

12.75 376.59 361.89 8.236 8 - 3.8 4.352 0.582 7.1
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Table N.4.4.

Automatic Temperature or Density Compensation

Temp °F

Pressure Liquid Density Vapor Density Vapor 

PSIA PSIG lb/gal (lb-oz)/gal lb/cu ft lb/gal Displacement %

13.00 378.09 363.39 8.230 8 - 3.7 4.371 0.584 7.1

13.25 379.59 364.89 8.224 8 - 3.6 4.390 0.587 7.1

13.50 381.10 366.40 8.219 8 - 3.5 4.410 0.589 7.2

13.75 382.61 367.91 8.213 8 - 3.4 4.429 0.592 7.2

14.00 384.13 369.43 8.207 8 - 3.3 4.449 0.595 7.2

14.25 385.65 370.95 8.201 8 - 3.2 4.468 0.597 7.3

14.50 387.17 372.48 8.195 8 - 3.1 4.488 0.600 7.3

14.75 388.70 374.01 8.189 8 - 3.0 4.508 0.603 7.4

15.00 390.24 375.54 8.183 8 - 2.9 4.527 0.605 7.4

15.25 391.78 377.08 8.177 8 - 2.8 4.547 0.608 7.4

15.50 393.32 378.62 8.171 8 - 2.7 4.567 0.611 7.5

15.75 394.87 380.17 8.165 8 - 2.6 4.587 0.613 7.5

16.00 396.42 381.72 8.159 8 - 2.5 4.608 0.616 7.5

16.25 397.98 383.28 8.153 8 - 2.4 4.628 0.619 7.6

16.50 399.54 384.84 8.147 8 - 2.3 4.648 0.621 7.6

16.75 401.10 386.41 8.141 8 - 2.2 4.669 0.624 7.7

17.00 402.67 387.98 8.134 8 - 2.2 4.689 0.627 7.7

17.25 404.25 389.55 8.128 8 - 2.1 4.710 0.630 7.7

17.50 405.82 391.13 8.122 8 - 2.0 4.731 0.632 7.8

17.75 407.41 392.71 8.116 8 - 1.9 4.751 0.635 7.8

18.00 409.00 394.30 8.110 8 - 1.8 4.772 0.638 7.9

18.25 410.59 395.89 8.104 8 - 1.7 4.793 0.641 7.9

18.50 412.19 397.49 8.098 8 - 1.6 4.814 0.644 7.9

18.75 413.79 399.09 8.092 8 - 1.5 4.835 0.646 8.0

19.00 415.39 400.70 8.085 8 - 1.4 4.857 0.649 8.0

19.25 417.00 402.31 8.079 8 - 1.3 4.878 0.652 8.1

19.50 418.62 403.92 8.073 8 - 1.2 4.900 0.655 8.1

19.75 420.24 405.54 8.067 8 - 1.1 4.921 0.658 8.2

20.00 421.86 407.17 8.061 8 - 1.0 4.943 0.661 8.2
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N.4.5. 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. When 

conducting the tests, the discharge rates shall be within the minimum and maximum discharge rates as marked by the 

manufacturer. For devices equipped with an automatic temperature or density compensator, results shall be based on 

tests with either:

(1) all runs conducted with the compensated (net) volume (e.g., with the temperature or density compensator 

activated); or

(2) all runs conducted with the uncompensated (gross) volume (e.g., with the temperature or density 

compensator deactivated).

(Amended 2019)

T. Tolerances

T.1. Application.

T.1.1. To Underregistration and to Overregistration. – The tolerances hereinafter prescribed shall be applied 

to errors of underregistration and errors of overregistration.

T.2. Tolerance Values. – The maintenance and acceptance tolerances for normal and special tests shall be as shown 

in Table T.2. Accuracy Classes and Tolerances for Carbon Dioxide Liquid-Measuring Devices.

Table T.2.

Accuracy Classes and Tolerances for Carbon Dioxide Liquid-Measuring Devices

Accuracy 

Class Application

Acceptance 

Tolerance

Maintenance 

Tolerance

Special Test 

Tolerance

2.5 Liquid carbon dioxide 1.5 % 2.5 % 2.5 %

(Table Added 2003) (Amended 2003)

T.2.1. 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 % of the absolute value of the maintenance 

tolerance and the results of each test shall be within the applicable tolerance. Also see N.4.5. Repeatability Tests.

(Added 2002) (Amended 2019)

T.3. On Tests Using Transfer Standards. – To the basic tolerance values that would otherwise be applied, there 

shall be added an amount equal to two times the standard deviation of the applicable transfer standard when compared 

to a basic reference standard.

UR. User Requirements

UR.1. Installation Requirements.

UR.1.1. Discharge Rate. – A device shall be so installed that the actual maximum discharge rate will not 

exceed the rated maximum discharge rate. If necessary, means for flow regulation shall be incorporated in the 

installation.
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UR.1.2. Length of Discharge Hose. – The discharge hose shall be of such a length and design as to keep 

vaporization of the liquid to a minimum.

UR.1.3. Maintenance of Liquid State. – A device shall be so installed and operated that the product being 

measured shall remain in the liquid state during passage through the meter.

UR.2. Use Requirements.

UR.2.1. Return of Indicating and Recording Elements to Zero. – The primary indicating elements (visual) 

and the primary recording elements shall be returned to zero immediately before each delivery.

UR.2.2. Condition of Discharge System. – The discharge hose, up to the valve at the end of the discharge 

hose, shall be completely filled and pre-cooled to liquid temperatures before a “zero” condition is established and 

prior to the start of a commercial delivery. Means shall be provided to fill the discharge hose with liquid prior to 

the start of a delivery.

UR.2.3. Vapor Equalization Line. – A vapor equalization line shall not be used during a metered delivery 

unless the quantity of vapor displaced from the buyer’s tank to the seller’s tank is deducted from the metered 

quantity. The appropriate correction values shall apply as specified in Table N.4.4.

UR.2.4. Temperature or Density Compensation.

UR.2.4.1. Use of Automatic Temperature or Density Compensators. – Devices equipped with an 

automatic temperature or density compensator shall have the compensator connected, operable, and in use at 

all times. Such automatic temperature or density compensator may not be removed.

UR.2.4.2. Tickets or Invoices. – Any written invoice or printed ticket based on a reading of a device that 

is equipped with an automatic temperature or density compensator shall have shown thereon that the quantity 

delivered has been temperature or density compensated.

UR.2.5. Ticket in Printing Device. – A ticket shall not be inserted into a device equipped with a ticket printer 

until immediately before a delivery is begun, and in no case shall a ticket be in the device when the vehicle is in 

motion while on a public street, highway, or thoroughfare.

UR.2.6. Sale by Weight. – All quantity determinations shall be made by means of an approved and sealed 

weighing or measuring device. All sales shall be stated in kilograms or pounds.
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