### Test Procedure for Leaks from Small Containers of Automotive Refrigerant

TP-503

Adoption Date: July 20, 2009 As Last Amended: January 5, 2010

NOTE: This document, approved by the Air Resources Board at its January 22, 2009 hearing for incorporation by reference in California Code of Regulations (CCR), title 17, sections 95360 through 95370, was originally shown without underline as permitted by California Code of Regulations, title 1, section 8. The modifications are indicate d in underline to indicate additions and in strikeout to indicate deletions.TP503, Page i TABLE OF CONTENTS

1. APPLICABILITY ......................................

................................................... .............................. 1

2. PRINCIPLE AND SUMMARY OF TEST PROCEDURE ............ ......................................... 1

3. BIASES AND INTERFERENCES ...........................

................................................... .............. 2

4. SENSITIVITY AND RANGE ..............................

................................................... ................... 3

5. EQUIPMENT ..........................................

................................................... ................................. 3

6. CALIBRATION PROCEDURES.............................

................................................... .............. 3

7. CAN PREPARATION....................................

................................................... ......................... 4

8. CAN WEIGHING .......................................

................................................... ............................. 4

9. CALCULATIONS.......................................

................................................... ............................. 6

10. RECORDING AND REPORTING DATA.......................

................................................... ..... 7

11. QUALITY ASSURANCE / QUALITY CONTROL................ ................................................ 7

ATTACHMENT A.......................................

................................................... ................................... 11TP503, Page 1 

### California Environmental Protection Agency

Air Resources Board

TP-503

Test Procedure for Leaks from Small Containers of A utomotive Refrigerant

The definitions in Section 95361 of Title 17, Calif ornia Code of Regulations (CCR) apply to this test procedure.

In these procedures, the term "ARB" refers to the C alifornia Air Resources Board, and the term "Executive Officer" refers to the ARB Executive Officer or his or her authorized representative.

1. APPLICABILITY

This test procedure is used by manufacturers of sma ll containers of automotive refrigerant and ARB to determine the leakage rate o f small containers of automotive refrigerant that are subject to the requirements of Title 17,CCR section 95360 et seq. Specifically, this test procedure will specify the equipment, procedures, and calculations to determine if a small container of a utomotive refrigerant complies with the leakage rate specified in section 2.1(B) of the Certification Procedures for Small Containers of Automotive Refrigerant, adopted [BARC U will insert] July 20, 2009, and last amended on [INSERT DATE OF AMENDMENT],

Requirement to Comply with All Other Applicable Cod es and Regulations

Approval of a small container of automotive refrige rant by the Executive Officer does not exempt the container from compliance or with ot her applicable codes and regulations such as local, State or federal safety codes and regulations.

Safety

This test procedure involves the use of materials u nder pressure, and operations and should only be used by or under the supervision of those familiar and experienced in the use of such materials and operat ions. Appropriate safety precautions should be observed at all times while p erforming this test procedure.

2. PRINCIPLE AND SUMMARY OF TEST PROCEDURETP503, Page 2

This procedure is used to determine the leakage rat e of small containers of automotive refrigerant (small cans). Testing will involve subjecting both full and partially empty cans in both upright and inverted p ositions at two temperatures: 73 o F and 130 o F.

Thirty cans are tested under each condition for a t otal of 240 cans tested. Cans are brought to temperature stability, weighed, then sto red for 30 days under specified conditions of temperature, orientation, and state o f fill, then re-weighed. Leakage rate (grams/year) is estimated by (weight loss in g rams) *365 / (days duration). The leakage rate is then compared to a standard of 3 gr ams/year to determine if a given small can complies with the leakage rate specified in section 2.1(B) of the Certification Procedures for Small Containers of Au tomotive Refrigerant, adopted [BARCU will insert] July 20, 2009, and last amended on [INSERT DATE OF AMENDMENT],

.

3. BIASES AND INTERFERENCES

3.1. Contaminants on the operator’s hands can affec t the weight of the can and the ability of the can to absorb moisture. To avoi d contamination of the can, the balance operator should wear gloves while handling the small

cans.

3.2. Weight determinations can be interfered with b y moisture condensing on the can and by thermal currents generated by temper ature differences between the can and the room temperature. The smal l cans cool during discharge and could cause condensation. For these reasons, cans must be equilibrated to balance room temperature for at least four hours before weighing.

3.3. Variations in the temperature, pressure, and h umidity of the ambient air will cause variations in the buoyancy of the small can. These variations should typically be less than 25 mg for a small can . If the can is not leaking at all, then the uncorrected weight changes will be within the range of 0 +/- 25 mg, which is about ten percent of the 2 47 mg loss expected after thirty days for a can leaking at 3 g/yr. In that case buoyancy corrections can be omitted. If the absolute value of the uncorrected weight change exceeds 25 mg, then all calculations must be made using weights corrected for buoyancy based on the tempera ture, pressure, and humidity of the weighing room.

3.4. Some electronic balances are sensitive to the effects of small static charges. The small can should be placed directly o n the balance pan, ensuring metal to metal contact. If the balance pan is not grounded, the can and balance pan should be statically discharged before weighing.TP503, Page 3

4. SENSITIVITY AND RANGE

The mass of a full can could range from roughly 50 to 1000 grams depending on the container capacity. A top loading balance, capable of a maximum weight measurement of not less than 1,000 grams and having a minimum readability of 0.001 gram, reproducibility and linearity of ± 0.00 2 grams, must be used to perform mass measurements (examples: Sartorius LA1200S, Met tler XS1003S, etc).

5. EQUIPMENT

5.1. A top loading balance that meets the requireme nts of Section 4 above. 5.2. A NIST traceable working standard mass for bal ance calibration. A NIST traceable working standard mass for a balance linea rity check. A reference mass to serve as a “blank” can. 5.3. A enclosure capable of controlling the interna l air temperature from 73 o F +/- 5 o F and an enclosure capable of controlling the inter nal air temperature to 130 o F, +/- 5 o F. 5.4. A temperature instrument capable of measuring the internal temperature of the temperature conditioning enclosures and the bal ance room with a sensitivity of +/- 2 o F. 5.5. A barometric pressure instrument capable of me asuring atmospheric pressure at the location of the balance to within + /- 0.02 inches of mercury. 5.6. A relative humidity measuring instrument capab le of measuring the relative humidity (RH) at the location of the balance with a sensitivity of +/-2% RH. 5.7. A hose with appropriate fitting for dispensing refrigerant from the small can to a recovery machine. 5.8. A refrigerant recovery machine to collect the discharged refrigerant from cans being tested.

6. CALIBRATION PROCEDURES

Calibrations are applied to the balance and to the support equipment such as temperature, humidity, and pressure monitoring equi pment. Procedures for calibration are not spelled out here. General cali bration principals for the support equipment and the balance are described in Section 11, Quality Assurance / Quality Control. Detailed calibration procedures for measu rement made using the balance are contained in Balance Protocol (BP–A1) “Balance Protocol for Gravimetric Determination of Sample Weights using a Precision B alance” adopted [BARCU will insert] July 20, 2009, and last amended on [INSERT DATE OF AMENDMENT], which is incorporated by reference herein.TP503, Page 4

7. CAN PREPARATION

7.1. Receive a batch of 240 cans of one design to b e tested. These may include several SKUs from different manufacturers if the co ntainer and valve combination are the same. 7.2. Clean cans with Alkanox solution or equivalent and dry with lint free towel. 7.3. Confirm that the sample ID sticker on the can matches the sample ID on the chain of custody forms. 7.4. Select a reference mass similar to the weight of a full can. If multiple sets of similar sized cans are being tested, only one re ference mass is needed; it can be used with all sets. Store the reference m ass in the balance area. 7.5. Discharge the contents of one half of the cans (120 cans) into the refrigerant recovery machine using normal DIY dispe nsing procedures until each small can is approximately half full. 7.6. Select a reference mass similar the weight the half full small can. If multiple sets of similar size cans are being tested, only on e reference mass is needed; it can be used with all sets. Store the ref erence mass in the balance area.

8. CAN WEIGHING

Weighing cans on the balance is done in accordance with Balance Protocol (BP-A1) adopted [BARCU will insert] July 20, 2009 and last amended on [INSERT DATE OF AMENDMENT] , which is incorporated by reference herein. The Ba lance Protocol describes how to conduct weight determinations incl uding appropriate calibration and QC data. This section, Can Weighing, describes the overall process, not the details of how to use the balance.

Initial Weights 8.1. Put on gloves. Check the cans for contaminatio n. 8.2. Place the 240 cans into a location where they can equilibrate to balance room temperature. Record the can test IDs and the equilibration start time on the Small Can Test Data Forms (Form TP–503– 01) in sets of thirty, one form for each of the eight each test conditions

. 8.3. Let cans equilibrate for at least four hours. 8.4. Weigh the set of 240 cans and the reference we ights using the Balance Protocol (BP–A1) “Balance Protocol for Gravimetric Determination of Sample Weights using a Precision Balance” adopted [ BARCU will insert] July 20, 2009 and last amended on [INSERT DATE OF A MENDMENT]

, which is incorporated by reference herein, and log the results to theTP503, Page 5 Balance Weighing Log Form (Form TP–503–02) attached to this test procedure. 8.5. Transfer data from the Balance Weighing Log Fo rm to the Small Can Test Data Forms in sets of 30, one set for each of the e ight conditions to be tested.

Thirty-Day Soak 8.6. Place each set of 30 cans into the appropriate orientation and temperature for soaking:

30 full cans – 73 o F, upright

30 full cans – 73 o F, inverted

30 full cans – 130 o F, upright

30 full cans – 130 o F, inverted

30 half-full cans – 73 o F, upright

30 half-full cans – 73 o F, inverted

30 half-full cans – 130 o F, upright

30 half-full cans – 130 o F, inverted 8.7. Soak the cans for 30 days undisturbed.

Final Weighing 8.8. Place the 240 cans into a location where they can equilibrate to balance room temperature. 8.9. Let the cans equilibrate for at least four hou rs. 8.10. Weigh the set of 240 cans, the reference weig hts, and any additional sets of cans using the Balance Protocol (BP–A1) “Balance Protocol for Gravimetric Determination of Sample Weights using a Precision Balance” adopted [BARCU will insert] July 20, 2009 and last amended on [INSERT DATE OF AMENDMENT] , which is incorporated by reference herein. 8.11. Transfer data from the Balance Weighing Log F orm to the corresponding Small Can Test Data Forms.

Can Storage (only applicable to ARB) 8.12. If the cans can pass the leak rate criteria, the cans may be recycled. (Return the cans to the place of purchase for recyc ling). 8.13. If the cans do not pass the leak rate criteri a, then mark the set with the message “Hold until released by Enforcement Divisio n”. Transfer the entire set of cans to safe storage location.TP503, Page 6

9. CALCULATIONS

Corrections for Buoyancy

The calculations in this section are described in t erms of “weight.” Mass is a property of the can, whereas weight is a force due to the effects of buoyancy and gravity. Procedures for correcting the effect of b uoyancy are given in Attachment A of this procedure. Ignoring buoyancy, i.e. using w eight data uncorrected for buoyancy effects, is acceptable for a thirty day te st if the absolute magnitude of the weight change is less than 25 mg. If the uncorrecte d weight change exceeds 25 mg for any can, then correct all can weights for buoya ncy using the procedures in Attachment A before performing the calculations des cribed below.

Calculation of Leak Rate

The emission rate in grams/day for each can is calc ulated by subtracting the final weight from the initial weight and then dividing th e weight difference by the time difference measured in days to the nearest hour (ne arest 1/24 of a day). The emission rate in g/day is multiplied by 365 to dete rmine emission rate in grams/yr. If the annual emission rate for any can exceeds the entire can contents, then the annual emission rate for that can is adjusted to eq ual the entire can contents/year (e.g., about 350 g/yr for a 12 ounce can). The annu al emission rate for the purpose of the test is calculated by averaging the 240 indi vidual adjusted annual emission rates and rounding to 2 decimal places. The cans fa il the test if the adjusted annual emission rate averaged over 240 cans is greater tha n 3.00 grams/yr. The calculations are described below.

Loss rate for each can

E i

daily = (W i

final – W i

initial ) / (D i

final – D i

initial ), grams/day E i

annual = 365* E i

dailly grams/year E I

adjusted = Minimum of (E i adjusted , C i /year) grams/yr

Where, E i = emission rate W i

final = weight of can i

after soaking (grams) W i

initial = weight of can I before soaking (grams) D i

final = date/time of final weight measurements (days) D i

initial = date/time of initial weight measurements (days) C i = original factory mass of refrigerant in can i

Note Date/Times are measured in days. Microsoft Exc el stores dates and times in days, and the calculations can be made directly in Excel. If calculations are made manually, calculate serial days to the nearest hour for each date and time as follows:TP503, Page 7

D = Julday + Hour/24

Where, Julday = serial day of the year: Jan 1 = 1, Jan 31 = 31, Feb 1 = 32, etc. Hour = hour of day using 24-hour clock, 0 to 23

Calculate the average loss rate for the 240 cans as follows:

E mean = [Sum(E adjusted i ), i =1 to 240 ] /240

10. RECORDING AND REPORTING DATA

During can weighing, record the can weights and dat e/times on the Balance Weighing Log Form. After each weighing session, tr ansfer the measured weights and date/times from the Balance Weighing Log Form t o the Small Can Test Data Form.

At the end of the test, complete the calculations d escribed in Section 9, Calculations, and record the results on the Small Can Test Data F orms.

At the end of the test, transmit a copy of the Smal l Can Test Data Forms to the Project Engineer.

11. QUALITY ASSURANCE / QUALITY CONTROL

11.1. All temperature, pressure, and humidity instr uments should be calibrated at least annually against NIST traceable laboratory st andards. The main purpose of the NIST traceable calibration is to est ablish the absolute accuracy of the device. The instruments should als o be checked periodically such as weekly, monthly, or quarterly against intermediate standards or against independent instruments. For example, a thermocouple can be checked weekly against a wall t hermometer. A barometer or pressure gauge can be checked weekly b y adjusting to sea level and comparing with local airport data. The m ain purpose of the frequent checks is to verify that the device has no t failed in some way. This is especially important for electronic devices such as a digital thermometer, but even a liquid filled thermometer c an develop a problem such as a bubble.

11.2. The balance should be serviced and calibrated at least annually by an independent balance service company or agency using NIST traceable reference masses. Servicing verifies accuracy and linearity, and the maintenance performed helps ensure that a malfuncti on does not develop.TP503, Page 8

11.3. The balance must also be calibrated and its l inearity checked with working standards before and after each weighing session, o r before and after each group of 24 cans if more than 24 cans are weighed i n a session. Procedures for calibrating and using the balance, a s well as recording balance data, are described in the accompanying bal ance weighing protocol. These procedures include zero checks, ca libration checks, and reference mass checks. Procedures for calculating quality control data from those checks are described in the balance prot ocol.

11.4. The small containers are cleaned then handled using gloves to prevent contamination. All equilibration and soaking must be done in a dust free

area.TP503, Page 9 Form TP–503–01: Small Can Test Data Form

Enforcement Lot ID Full: Upright: T=73 F: Half full: Inverted: T= 130 F:

Date: _______ Date: _______ Adjusted Initial Initial Final Final Delta Delta Annual time weight Time Weight Days Weight Rate Can ID (hour) (g) (hour) (g) (g) (g/yr)

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Number of Samples: _________ Average Loss Rate:

_________ Technician: _________ Standard Deviation:

_________

Comments:TP503, Page 10Form TP–503–02: Balance Data Log FormQC Can Can RecordedRec # Date Time Proj. Prot. Tech. Code Type ID# grams Comment12345678910111213141516171819202122232425TP503, Page 11



### Attachment A
Compensation of Weight Data for Buoyancy and Gravit y Effects

Gravity

Variations in gravity are important only when weigh ing objects under different gravitational fields, i.e. at different locations o r at different heights. Since the balance procedures calibrate the balance against a known ma ss (the calibration “weight”) at the same location where sample objects are weighed, the re is no need to correct for location. Although both the sample and the calibra tion weight are used at the same location, there will be a difference in the height of the center of gravity of the sample object (small can) and the center of gravity of the reference mass (calibration weight). However, this difference in height is maintained du ring both the initial weights and final weights, affecting the initial and final weights by the same amount, and affecting the scale of the weight difference by only a few ppm. I n any event, the magnitude of this correction is on the order of 0.3 ug per kg per mm of height difference. A difference on the order of 100 mm would thus yield a weight diffe rence of about 0.03 mg, which is insignificant compared to our balance resolution wh ich is 0.001 g or 1 mg.

Based on the discussion above, no corrections for g ravity are necessary when determining weight changes in small cans.

Buoyancy

Within a weighing session, the difference in densit y between the sample object and the calibration weight will cause the sample object wei ght value to differ from its mass value due to buoyancy. For a 1-liter object in air at 20 o C and at 1 atm, the buoyant force is about 1.2 grams. The volume of a 1 kg object with a density of 8 g/cm3 (e.g. a calibration weight), is about 0.125 liters, and the buoyancy force is about 0.15 g. Variations in air density will affect both of these values in proportion. The net value being affected by variations in air density is thus on the order of 1.2 - 0.15 = 1.05 g. Air density can vary up or down by 2% or more due to va riations in barometric pressure, temperature, and humidity. The buoyancy force will then vary up or down by 0.02 g, or 20 mg. This is significant compared to the weight change expected after one week for a can leaking at 3 grams per year, which is 57 mg.

Based on the discussion above, buoyancy corrections must be made.

Variables measured or calculated:

V can = volume of can (cm 3 ). Estimate to within 10% by measuring the can dim ensions or by water displacement. Error in the can volume will cause an error in the absolute amount of the buoyancy force, but will hav e only a small effect on the change in buoyancy force from day to day.TP503, Page 12

W can = nominal weight of a can (g), used to calculate t he nominal density of the can

ρ can = nominal density of a small can (g/cm 3 ). The nominal values can be applied to corrections for all cans. It is not necessary to c alculate a more exact density for each can. Calculate once for a full can and once fo r a half full can as follows:

ρ can = W can / V can
T = Temperature in balance chamber (degrees Celsiu s)

RH = Relative humidity in balance chamber (express ed a number between 0 and 100)

P baro = Barometric pressure in balance chamber (millibar) . Use actual pressure, NOT pressure adjusted to sea level.

ρ air = density of air in the balance chamber (g/cm 3 ). Calculate using the following approximation

ρ air = 0.001* [0.348444*P baro – (RH / 100)*(0.252*T – 2.0582)] / ( T + 273.15)

ρ ref = the reference density of the calibration weight (g/cm 3 3 ). Should be 8.0 g/cm 3

.

Equation to correct for buoyancy

W corrected = W reading * (1 - ρ air / ρ ref ) / (1 - ρ air

/ ρ can )