Page 1 of 3 CALIFORNIA DEPARTMENT OF FOOD AND AGRICULTURE  
Hydrogen Gas -Measuring Device s (3.39) 
CCR Title 4, § 4002.9  
 
May 31, 2019  
 
 
PROPOSED TEXT OF THE REGULATIONS  
 
The proposed additions to original text are single underlined , 
and the proposed deletions are single strikethrough . 
 
§ 4002.9. Hydrogen Gas -Measuring Devices (3.39).  
 
A.4. Type Evaluation. – The National Type Evaluation Program (NTEP) or California Type 
Evaluation Program (CTEP) will accept for type evaluation only those hydrogen gas -measuring 
devices that comply with all applicable requirements of this device . 
 
S.5.2. Location of Accuracy C lass 3.0, 5.0, 7.0, and 10.0 Information : – An additional Accuracy 
Class statement shall be placed adjacent to the quantity display on the face for the dispenser 
and shall be conspicuously, legibly, and indelibly marked with a statement such as “The 
Accuracy Class of this dispenser is XX.0 and repr esents the accuracy of the delivery 
expressed as a plus or minus percentage of the delivered quantity”. The lettering shall be in 
Helvetica or Arial Bold font type, in all capitals, and no less than 3/16 inch (0.48 cm)  in height.  
 
Note: The XX.0 is the Acc uracy Class as stated on the certificate of approval issued by the 
California Department of Food and Agriculture after successful type evaluation , and is part of 
the identification information required in paragraph S.5. The rating represents the allowable 
limits of error expressed as a plus and minus value. For example, a dispenser approved and 
marked with a  3.0 7.0 Accuracy Class has an allowable maintenance tolerance in Table 
T.2. Accuracy Classes and Tolerances for Hydrogen Gas -Measuring Devices  ranging from 
plus three (+3)  seven (+7)  percent to minus  three ( -3) seven ( -7) percent.  
EXAMPLE:  
 
N.3. Test Drafts. -– The minimum test shall be one test draft at twice the declared minimum 
measured quantity and one test draft at approximately ten times the minimum measured 
quantity or 1 kg, whichever is greater. More tests may be performed over the range of normal 
quanti ties dispensed. (See T.3. Repeatability)  
THE ACCURACY CLASS OF THIS 
DISPENSER IS 7.0 AND 
REPRESENTS THE ACCURACY 
OF THE DELIVERY EXPRESSED 
AS A PLUS OR MINUS 
PERCENTAGE OF THE 
DELIVERED QUANTITY. Page 2 of 3 The test draft shall be made at flows representative of that during normal delivery. The 
pressure drop between the dispenser and the proving system shall not be greater than that for 
normal deliveries. The control o f the flow (e.g., pipe work or valve(s) size, etc.) shall be such 
that the flow of the measuring system is maintained within the range specified by the 
manufacturer.  
N.4.1. Master Meter (Transfer) Standard Test. -– When comparing a measuring system with a  
calibrated transfer standard, the minimum test shall be one test draft at twice the declared 
minimum measured quantity and one test draft at approximately ten times the minimum 
measured quantity or 1 kg, whichever is greater. More tests may be performed o ver the range 
of normal quantities dispensed.  
N.4.2. Gravimetric Tests. -– The weight of the test drafts shall be equal to at least twice the 
amount delivered by the device at the declared minimum measured quantity and one test draft 
at approximately ten times the minimum measured quantity or 1 kg, whichever is greater. More 
tests may be performed over the range of normal quantities dispensed.  
N.4.3 . PVT Pressure Volume Temperature Test. -– The minimum test with a calibrated 
volumetric standard shall be o ne test draft at twice the declared minimum measured quantity 
and one test draft at approximately ten times the minimum measured quantity or 1 kg, 
whichever is greater. More tests may be performed over the range of normal quantities 
dispensed.  
N.6.1.1. Re peatability Tests. -– Tests for repeatability should include a minimum of three 
consecutive test drafts of approximately the same size with no less than 1000 scale intervals 
(divisions), and be conducted under controlled conditions where variations in factors are 
reduced to mi nimize the effect on the results obtained.  
T.2. Tolerances. -– The tolerances for hydrogen gas -measuring devices are listed in Table 
T.2. Accuracy Classes and Tolerances for Hydrogen Gas -Measuring Devices.  
1 The tolerance values for Accuracy Classes 3.0 and 5.0 hydrogen gas -measured devices are 
applicable to devices installed prior to January 1, 2020.  Page 3 of 3 2 The tolerance values for Accuracy Classes 10.0 hydrogen gas -measured devices are 
applicable to devices ins talled prior to January 1, 2018.  
T.3. Repeatability. -– When multiple tests are conducted at approximately the same flow rate 
and draft size greater than 1000 scale intervals (divisions), 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. See also Section 4002.9 -– 
N.6.1.1. Repeatability Tests.  
T.6. Tolerance . -– Minimum  Measures  Measured  Quantity (MMQ). The maximum error 
applicable to the minimum measured quantity is twic e the applicable tolerance in Table 
T.2. Accuracy Classes and Tolerances for Hydrogen Gas -Measuring Devices . 
Note: Authority cited: Sections 12027 and 12107, Business and Professions Code. Reference: 
Section 12107, Business and Professions Code.