# Mr. Attila Sonkoly — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 15-0055
- **title:** Mr. Attila Sonkoly — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2015-11-25
- **effective on:** Not available
- **summary:** 15-0055 concerning 180.205.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-15-0055.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-15-0055.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-15-0055
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2015/150055.pdf
**body:**

<<<PAGE 1>>>

U.S. Department
of Transportation
Pipeline and Hazardous
Materials Safety
Administration
1200 New Jersey Avenue SE
Washington. DC 20590
NO\I 2 5 1~'~
Mr. Attila Sonkoly
Hydro Test Operator
1217 W. Ball St.
Plant City, FL 33563
Ref. No.: 15-0055
Dear Mr. Sonkoly:
This is in response to your February 5, 2015 letter requesting clarification of the Hazardous
Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the calibration and
certification of gauges used for pressure testing cylinders. Your questions are paraphrased
below:
QI. You state that it is your understanding that a pressure-indicating device (PID) must
have an accuracy grade of0,5%, and that if your PID exhibited an accuracy grade of 0.6%
you would not be able to use that measuring device for pressure testing. You ask for
confirmation of your understanding.
Al. .For the purposes of this answer, and all other answers in this letter, it is important to
note that the term accuracy grade is not a term used in the HMR. Your understanding is
correct. As required by § 180.205(g)(3)(i) the PID, itself, must be certified as having an
accuracy of ±0.5%, or better, of its full range. If your PID exhibited an accuracy grade of
0.6% you would not be able to use that measuring device for pressure testing.
Q2. You give an example of a 0 to 11,000 PSI PID with 0.5% accuracy grade (the PID is
+/- 55 psi accurate at any point). You request confirmation of your understanding that you
could not test any cylinder under the test pressure of 5,500 psi.
A2. Your understanding is correct. Section 180.205(g)(3)(i) states that the PID, as part of
the retest apparatus, is accurate within ±1.0% of the prescribed test pressure of any cylinder
tested that day. For additional tests to be conducted that day, PID, as part of the retest
apparatus, must be accurate within ±1.0% of each individual test pressure to be tested that
day. However, ifthe PID, itself, is not in compliance with an accuracy of ±0.5%, or better,
of its full range, retesting is not permitted on that day.

<<<PAGE 2>>>

Q3. You present a scenario where you are testing cylinders with a test pressure range of
3,000 to 10,000 psi on a daily basis. You note that you understand you should have a 0 to
11,000 psi gauge to comply with the +/- 10% range rule and ask if a PID with a 0.5%
accuracy grade is not adequate, but if a 0.25% accuracy grade would be appropriate.
A3. In the scenario you provide the PID with 0.5% accuracy would not be appropriate for
testing all cylinders within the psi range you have provided. A PID with 0.25% accuracy
would be compliant.
Q4. Using the same scenario as described in Q3 above (0.25% accuracy grade), you ask if
you are unable to prove your PID is+/- 30 psi accurate that it would be a violation to test
cylinders with the pressure of 3,000 psi or lower.
A4. It is unclear as to intent of your question. Other than verification each day before
retesting, there is no requirement in the HMR to retest the PID during the day.
Q5. You state it is your understanding that an expansion-indicating device (EID) must have
an accuracy of+/- 0 .5 % or better of its full range. You ask if this means the accuracy grade
of the EID has to be at least 0.5%.
A5. As required by§ 180.205(g)(3)(ii) the expansion-indicating device, as part of the retest
apparatus, gives a stable reading of expansion and is accurate to ±1.0% of the total
expansion of any cylinder tested or 0.1 cc, whichever is larger. The expansion-indicating
device itself must have an accuracy of ±0.5%, or better, of its full scale. ·
Q6. You provide a scenario in which you are using a 0 to 1,000 g (1 g = 1 ml) digital scale
as an EID with 0.5% accuracy grade (1000 x 0.5/100 = 5 g accurate). You ask ifit would
be a violation to test cylinders producing total expansion of less than 500 g.
A6. Each day before retesting, the retester shall confirm that the expansion-indicating
device, as part of the retest apparatus, gives a stable reading of expansion and is accurate to
±1.0% of the total expansion of any cylinder to be tested that day or 0.1 cc, whichever is
larger. In the scenario you describe, testing cylinders producing total expansion of less than
500 g would be a violation.
Q7. You present a scenario where the total expansion ranges from 6 ml to 510 ml and you
are using a 0 to 1,000 g scale. You state it is your understanding that you would need a
0.01 % accuracy grade and not a 0.5% accuracy grade.
A7. The expansion-indicating device, as part of the retest apparatus, must be is accurate to
±1.0% of the total expansion of any cylinder to be tested that day or 0.1 cc, whichever is
larger.
Q8. You ask several questions about verifying EID accuracy using Compressed Gas
Association (CGA) Pamphlet C-1, Methods for Pressure Testing Compressed Gas
Cylinders.

<<<PAGE 3>>>

A8. CGA Pamphlet C-1 is not incorporated by reference and, therefore, is not a material
made part of the regulations under the HMR and not enforceable.
I hope this information is helpful. If you have further questions, please do not hesitate to
contact this office.
Sincerely,
;J
·v~uA-7(/J
Duane Pfund V -
International Standards Coordinator
Standards and Rulemaking Division

<<<PAGE 4>>>

To: PHMSA Standards and Rulemaking Division
Formal Interpretation Letter Request
February 5, 2015
Attila Sonkoly Hydro Test Operator
4805 Heather Lyn Ct Apt H Phone # : 813-515-9678
Tampa, FL 33617
RE: Device accuracy while pressure testing compressed gas cylinders
Dear Sir,
Please assign this letter to an expert who has good knowledge of CFR 49 180.205 , who is expert on CGA C-1, and
knows how accuracy grade works.
CFR 49.180.205.
(i) The pressure-indicating device, as part of the retest apparatus, is accurate within ±1.0% of the prescribed
test pressure of any cylinder tested that day. The pressure indicating device, itself, must be certified as having an
accuracy of ±0.5%, or better, of its full range, and must pennit readings of pressure from 90%-110% of the
minimum prescribed test pressure of the cylinder to be tested. The accuracy of the pressure indicating device within
the test system can be demonstrated at any point within 500 psig of the actual test pressure for test pressures at or
above 3000 psig, or 10% of the actual test pressure for test pressures below 3000 psig.
(ii) The expansion-indicating device, as part of the retest apparatus, gives a stable reading of expansion and is
accurate to ±1.0% of the total expansion of any cylinder tested or 0.1 cc, whichever is larger. The expansion-
indicating device itself must have an accuracy of ±0.5%, or better, of its full scale
I am an experienced hydro test operator. Recently while attending two online seminars and while talking to
several instructors some of them said while checking the pressure indicating device (PID) against a master gauge the
PID can be 1 % off, others said it can be 0.5% percent off. When using digital scale as an expansion indicating
device (EID) some of the instructors said it can be I% off, others said it can be 0.5% off.
The worst thing I think all of them are wrong, and they do have a misconception on the concept of accuracy
grade. Accuracy is of the utmost importance for hydro testers, misunderstanding the above paragraphs can lead to
hard time while calibrating the system, it will result in incon-ect and illegal testing if misinterpreted.
I occasionally help out training hydro test operators - I would like to ask for a letter I can show to them so
they would get the con-ect concept on testing by CFR 49 accuracy standards.

<<<PAGE 5>>>

Both the EID and the PID accuracy is described by accuracy grade what gives the maximum error
that can occur at any point of the device. It is calculated by the largest acceptable error divided by the full
range multiplied by 100%. It is an inherent quality of the device. (see quote from CGA C-1)
Example ifI am using a 0 to 11,000 PSI PID with 0.5 % accuracy grade I can have at any point 11,000 x
0.5% = 55 PSI error the most. With other words my device is+/- 55PSI accurate. That is how all PIDs get certified
and recertified when checking against a standard (master gauge or dead weight).
Question 1. (THE 0.5% RULE) "The pressure indicating device, itself, must be certified as having an
accuracy of ±0.5%, or better, of its full range." To me it doesn't mean that the PID can be 0.5 percent off at all. It
means to me that the required accuracy grade I have to use for a PID is 0.5% or better. Ifl look at the accuracy
grade definition it is max error in percentage compared to the full range. So in technical terms CFR 49 tells me that
the PID should have at least a 0.5% accuracy grade. If it was for example 0.6% accuracy grade I would not be able
to use that measuring device for pressure testing.
I am attaching a CGA C-1 excerpt, a PHMSA interpretation letter and a Galiso Technical Bulleting to support my
statement on this. Please let me know if my understanding it c01Tect on this.
Question 2. (THE 1 % RULE) Most commonly misunderstood point between hydro test operators: "The pressure-
indicating device, as part of the retest apparatus, is accurate within ±1.0% of the prescribed test pressure of any
cylinder tested that day." To me this doesn't mean at all that the PID can be 1 % off at any point when
comparing it to a master guge. To me that seems impossible, as only the entirety of the system as a whole can
be 1 % off based on CFR 49. To me what it means that if I am using a O to 11,000 PSI PID with 0.5 percent
accuracy grade (the PID is+/- 55PSI accurate at any point) I cannot test any cylinder under the test pressure
of 5,500 PSI. For example ifI tested a cylinder with this PID at 3360 test pressure it could have a 55 PSI eITor and
that would be larger than 1 % of the test pressure of the cylinder what I am testing. IfI have a 0.5% accuracy grade
PID I can use it to hydro test cylinders but not every single one of them, sometimes ifthe test pressure is too small
compared to the entire test range a better accuracy grade is required based on the one percent rule.
Question 3. (PID applicability for high pressure cylinder testing facilities) If I am testing from 3,000 to 10,000
PSI test pressure range on a daily basis, I should have a 0 to 11,000 PSI gauge to comply with the+/- 10%
range rule. In this case 0.5% accuracy grade is not adequate, but a 0.25% accuracy grade 11,000PSI x 0.25%
= 27.5 PSI would be perfect, as 27.5 PSI is less than 1 percent of the 3,000 PSI test pressure.
Question 4. (PID verification) IfI want to verify ifthe before mentioned device (0 to 11,000 PSI range PID with
0.25% accuracy grade) is precise and meets the accuracy requirement set by CFR 49 (this might happen as part of
my troubleshooting during calibration or because I am following CGA C-1 appendix B and I am recertifying the
gauge after every sixth month using certified master gauges) when I put my pressure device against a master gauge
and if it gives larger than 30 PSI error at any point, with other words if I am unable to prove it is +/- 30 PSI
accurate (for example it gives a 50 PSI error t 6,000 PSI or gives 70 PSI error at 10,000 PSI) it would be
illegal to test cylinders with the pressure of 3,000 PSI or lower. The PID needs to get repaired or and recalibrated
as it is not meant to have errors of that magnitude.
See attached references which support my understanding.
Expansion Indicating Device (EID)
My understanding is similar as on PID, I will describe it shortly

<<<PAGE 6>>>

Question 5. (EID 0.5% rule) : The expansion-indicating device itself must have an accuracy of ±0.5%, or better, of
its full scale, to me this means that the accuracy grade of the EID has to be at least 0.5%.
Question 6. (EID 1 % rule) If I am using a 0 to 1,000g (lgramm = 1 ml) digital scale as an EID with 0.5%
accuracy grade it is 1000 x 0.5/100 = 5g accurate. It would be illegal to use to test cylinders producing total
expansion of less than 500g .
Question 7 (EID accuracy application to high pressure test facilities) If my total expansion ranges from 6 ml
to 510 ml, and if I am using a 0 to 1,000 g scale I need that to be at least+/- 0.1 g accurate what is 0.1 I 1,000 x
100% = 0.01 % accuracy grade. So given my scale range I would need a 0.01 % accuracy grade and not a
0.5% accuracy grade.
Question 8. Verifying EID. Ifl have to use a 0 to 1,000 g scale 0.01 % accuracy grade scale and I want to
verify its accuracy either for trouble shooting reason or because I wanted to do a periodical EID verification
as by CGA C-1 appendix B when placing different weights on the scale I should not have anywhere more
than 0.1 g error if I am testing cylinders producing total expansion lOg or lower on a daily basis.
Please let me know if my understanding is correct.
Sincerely,
();f;r:re .J1
after 3pm)

<<<PAGE 7>>>

Technical Bulletin
prassure-indicating device, as part of the retest apparatus, is accurate to within+ or - 1 % of the prescribed lest
. pressure of any cylinder tested that day. The pressure-indicating device, itself, must be certified as having an accuracy of+
or- 0.5%, or better, of it's fun range and must permit readings of pressure from 90% lo 1 l0%of the minimum prescribed
pressure of the cylinder to be tested. The ilceuracy of the pressure indicating device within the test system can be
onstrated at any point within 500 psi of the actual test pressure for test pressures al or above 3000 psi, or l 0% of the
lest pressure for test pressures below 3000 psi.:
1 0 /'~ f-u k_,
fl lM-Li ~ t f' Ch t.4i ~
~d L.,_\ Dt
f 'rt>;;,~Ul\t ~"-'\
Accuracy
~ tesi pressure of 10,000 psi, the gauge must read to 110% of this, i.e. 11,000 psi. ~
/ • If the gauge has an accuracy of 0.5% of full-scale, the gauge is on!y accurate lo 55 psi. This means at any given reading, the gauge
might be up to 55 psi in error.
• Since that gauge must be accumte to l % of the prescribed test pressure, at pressures below 5,500 psi, the gauge general
inaccuracy of 55 psi exceeds this l % fig um. The gauge is therefore not suitable for use below 5,500 psi
The chart below lists some popular gauge ranges and is based on the DOT prescribed accuracy of 112 %. N.B. Galiso
master gauges are 1/4 % accurate· exceeding DOT minima. ·~
Gauge max Max test Accuracy of Gauge possible frvlininunn test \
value psi pressure gauge % error /psi / pressure psi
d I
5,500
3,750
3,000
1,500
·~ \lo
Use of calibration cylinder co ~ Y"-4
o.:r~
The calibration cylinder must be used to verify equipment at 500 psi intervals above 3000 psi and within 1 o•.t of test
pressure below 3000 psi.
see relevant 49 CFR and CGA pamphlets. These items am not intended as a replacement for DOT specific training.
Information is given for 9uidance only and as a quick reference, The appropriate DOT regulations must be referred to for
further clarification.
\ 5
Ga!iso, Inc.® 1-800-854-3789/+970-249-0233

<<<PAGE 8>>>

~,GAliiso®
~_I· N C 0 R P 0 RA T E 0
PRESSURE GAUGE
Calibration· Certificate
PART NUMBER 36'- //-:2500.· SERIAL NUMBER EQ!i/08{~ ..
Pm:SSURE RANGE . 0 :-t~ o D Q P.S.I. ACCURACY aa$% FULL SCAL:I! :tiZmlil ;P,,$~1.
DATE OF CAUSRAl'ION: t~~J$ 13 CALIBRATED BY: ~·~-· #: J<il
. CALll!3'RA TfON
Received in Calibration:
YESD NO f2{]
NEW RE CAL REPAIR
D ~
D
1
I
r
r
I
t
~GAUi~~~
VJ.5j./"•..,. ;ci: W• -
-·ca~~-
QUALITY ASSURANCE . ,
Calibrated in
· Temperature
ti Pl?/&llf Position
t{C' °F
Calibration Control: Heise Model PM Digital Pressure Indicator SIN: 42180, 42179
LastCa:lib;ati.on: si20113 Next Calibration Due: 8/20/i4 .
Pressure Module Serial Numbers: 0-2500: #42180, 0-10,000 #42179
'.'This inStrumont has' been calibrated with measuremeht standards whose accuracy is traceable to National Institute of Staqdards
and Technolo~.(NJ.S'.T.);'
GAU SO INCORPORATED
22 PONDEROSA COURT (81401)
P.O. BOX 1468
MONTROSE, CO 8.1402
(970) 249-0233 (800) 854-3789 GS09504-1E

<<<PAGE 9>>>

. 1.
9gGAU$0®
0°'
PRESSURE GAUGE
Calibration Certificate
PART NUMBER _ 36-11-2500
SERIAL NUMBER EO510 85
PRESSURE RANGE _ O-11000_P.S.I. ACCURACY O.25% FULL SCALE +27.5a P.s.1.,
DATE OF CALIBRATION: 12-18-12 CALIBRATED BY: M. scott Balt EMP.#: 109
CALIBRATION
INCREASING PRESSURE
Received in Calibration:
YES.
NO
Applied Press.
Indicated Press.
Difference
NEW
RECAL
REPAIR
1000
990
=10
3000
2000
3000
3000
4000
3990
- 10
SALISO
5000:
5000
DATE PUT INTO SERVICE DEC 1 & 2012
6000
6000
Q
QUALITY ASSURANCE
cer st
7000
7000
8000
8000
9000
9010
t10
Calibrated in
UPRIGHt Position
10,000
10,010
' +/0
Temperature
66
°F
Calibration Control: Heise Model DXD Digital Pressure Indicator S/N: 7297
Last Calibration: 8/02/12Next Calibration Due: 8/2/13
"This instrument has been calibrated with measurement standards whose accuracy is traceable to National Institute of Standards
Pressure Module Serial Numbers: 0-10,000 S/N 7297
and Technology (N.I.S.T.)"
GALISO INCORPORATED
22 PONDEROSA COURT (81401)
MONTROSE, CO 81402
P.O. BOX 1468
(970) 249-0233 (800) 854-3789
GSO9504-1E
Revised a cA

<<<PAGE 10>>>

Licensed for the sole use of the purchaser. See license agreement penalties for distribution.
CGA C-1-2009 COMPRESSED GAS ASSOCIATION INC. PAGE 1
~~~~~~~~~"-!.!!!-'-"'=-":.:.:=:~~'-'='.~~'-'"""'~..!.!..:!.!"-'-..~~~~~~~~~~~
1 Introduction
Pressure testing of compressed gas cylinders is required for many newly manufactured cylinders and also is an
accepted test method for the requalification of cylinders. The referenced edition of the applicable documents,
as specified by the U.S. Department of Transportation (DOT) in Title 49 of the U.S. Code of Federal Regula-
tions (49 CFR), in Canada by Transport Canada (TC) in CSA 8339, Cylinders, Spheres, and Tubes for the
Transportation of Dangerous Goods, as referenced by the Transportation of Dangerous Goods Regulations, or
the authority having jurisdiction, shall be available at each facility conducting pressure testing/requalification
[1, 2, 3].
For the testing/requalification of cylinders manufactured under an exemption/special permit or permit, a current
copy of that exemption or permit shall also be available. (See Appendix A for addresses of agencies that pro-
duce these documents).
2 Scope
This standard contains operating and equipment requirements necessary to properly· perform pressure testing
of compressed gas cylinders.
3 Definitions
For the purpose of this standard, the following definitions apply.
3.1 Accuracy
Degree of conformity of a measured or calculated quantity to its actual (true) value ..
3.2 Accuracy grade
Inherent quality of the device.
NOTE-Accuracy grade expresses the maximum error allowed for the device at any reading and is expressed as a percent-
age of the full scale of the device.
3.3 Actual test pressure
True, recorded pressure applied to a cylinder during a test.
3.4 Bar
Metric measurement used for marking seririce pressure (1 bar= 14.5 psi).
3.5 Calibration
Process of adjusting a device to match a known standard so that it indicates to within specified accuracy limits.
NOTE-See Appendix B for information on calibration devices. '
3.6 Calibration verification
Checking of an individual .device or test apparatus by comparison with a given standard to determine the indi-
cation error at specified points of the scale.
3.7 Calibrated cylin.der
Cylinder that has certified calibration points of pressure with corresponding expansion values.
NOTE-It is a secondary, derived standard-used for the verification and demonstration of test system accuracy and integrity.
3.8 Condemn
Determination that a cylinder is unserviceable for continued transportation of dangerous goods and that the
cylinder may not be restored by repair, rebuild, requalification, or other procedures.
This document licensed for the .sole use of the purchaser. It may not be shared with any other person or used after the ~xpiration date
without the express written permission of the CGA. Any unauthorized use, reproduction, dis:ribution, or modificat10n ofth1s pnnted page
will result in a $5,000 liquidated damages fee plus loss of access to CGA publications for one year for your company·

<<<PAGE 11>>>

Licensed for the sole use of the purchaser. See license agreement penalties for distribution.
CGA C-1-2009 ________ -"C"-'O""M"'P-'-R""E'°'S""'S""E"'O-'G""A'-"S"-A'-=S"'-S;::O:o::,C""'/A!.i..T,,_,/O""N""-"/N"'C"".'------------PAGE 11
5.?..2.2 Pressure indicating device
The pressure indicating device (PIO) shall be a pressure gauge or other suitable devke sucn as a ptessurn
transducer and digital readout that:
shall be manufactured and certified to an accuracy grade of ±0.5% or better;
shall permit reading of pressures to within 1 % of the test pressure of each cylinder tested. For analog P/Ds,
interpolation to one half of the marked increment is permitted;
shall permit readings of pressures from 90% to 110% of the test pressure of any cylinder tested;
shall be accurate to ±1 % of test pressures; and
shall be recalibrated periodically in accordance with Appendix 8.
For example, using a 10 000 psi pressure gauge with an accuracy grade of ±0.5%, the reading is accurate to
±50 psi (0.5% x 10 000 psi) at any point on the pressure gauge. For a test pressure l?nge of 3000 psi to 5000 psi,
at 3000 psi the gauge accuracy rnay deviate by only ±30 psi (1% of 3000 psi) while for 5000 psi the gauge may
deviate by as much as ±50 psi.
NOTE-The gauge in this example satisfies the accuracy grade than ,gg~ since the gauge is only accurate to ±50 psi. at 30~ gauge with a smaller range (e.g., 5000 psi) or uirement but could not be used for test pressures less
n accuracy of ±30 psi is required for the minimum test pressure
e ccuracy (e.g., ±0.25%) is needed.
5.3.2.3 Pressure recording device
The use of a pressure recording device is not required. However, if used, the device should be compatible with
the maximum system pressure capability. The pressure recording device shall be adjustable so that correlation
with the PID can be achieved. ·
5.3.2.4 Associated plumbing
All pressure valves, fittings, and connecting tubing shall be of a size and material appropriate for the pressures
and the stresses of the test and be adequately sized and installed in a manner to prevent leakage, air entrap-
ment, or exposure to external damage. Additional pressure supply system components such as surge cham-
bers, reservoirs, pulsation dampeners, accumulators, etc., shall be selected with consideration to pressure cy-
cling capabilities and maximum test pressures. All pressure supply system components shall be properly se-
lected, installed, and maintained to ensure leak-free performance.
CAUTION: In the design and construction of the pressure system, consideration shall be given to the potential
hazards associated with the containment of liquids under high pressure. The use of additional safety equipment
such as relief devices, blast shields, test cages, etc., is advisable to prevent possible injury to testing personnel
and equipment.
5.3.3 Timing device
During testing, a timing device that is capable of accurately measuring the minimum test duration shall be used.
5.4 Calibrated cylinder
A calibrated cylinder is required when performing the verification procedure for test methods where volumetric
expansion determinations are required. The calibrated cylinder is a derived secondary standard used to dem-
onstrate test apparatus integrity and to confirm PIO and EID accuracy.
A calibrated cylinder is a cylinder that has been specially prepared so that it no longer experiences permanent
expansion at the pressures for which it has been calibrated. The expansion readings of the cylinder shall be
repeatable and linear. A certification for the cylinder noting the actual pressure and expansion values for each
pressure calibration level shall be available. The original signed certification of calibration should be maintained
in a safe place and a copy shall be posted on or near the hydrostatic test console.
This document licensed for the sole use of the purchaser. It may not be shared with any other person or used after the expiration date
without the express written permission of the CGA. Any unauthorized use, reproduction, distribution, or modification of this printed page
· - ---
c~~ -lnc lnoo ,.,f access to CGA publications for one year for your company.

<<<PAGE 12>>>

Licensed for the sole use of the purchaser. See license agreement penalties for distribution.
PAGE a. ___________ c=-o=M=P'-'R~E=s~s=Eo~G~A=s~A~s~so~c=1~AT~1~o~N~l~N~c·~ _______ cGA c-1-2009
Example 2: 92 - 2.3 = 89. 7
Cylinder expansions are measured with an EID such as a burette where the volume of water is measured in
cubic Gentimeters or measured with a weighing scale where the weight of water in grams is converted to cubic
centimeters. For the purpose of this standard, 1 g is equivalent to 1 cc. All expansion values are expressed in
cc.
See Appendix D for sample test record forms.
5.3 Test system components
5.3.1 Expansion system
5.3.1.1 Water jacket
The water jacket shall be of sufficient size to allow a cylinder to expand freely in all directions. The water jacket
and/or sealing head shall be designed to prevent leakage or air entrapment.
5.3.1.2 Expansion indicating device
The EID shall be a burette, scale, or other suitable device that:
shall permit reading of the cylinder expansion to within 1 % of the total expansion of each cylinder tested, or
0.1 cc, whichever is larger. Example: For total expansion readings of less than 10 cc, a reading to 0.1 cc is
acceptable. Interpolation to one half of the marked increment is permitted. The device shall give a stable
reading;
shall be accurate to within ±1 % of the total expansion of any cylinder tested, or 0.1 cc, whichever is larger
shall be designed to take into account the barometric effect of differing water levels (see Figure 5);
shall be certified as having an accuracy grade of ±0.5% or better. Example: A burette with a full scale of
150 cc and an accuracy grade of 0.5% would be accurate to a reading of 0. 75. cc. Therefore, this burette
shall not be used for total expansions less than 75 cc in order to maintain a ±1 % accuracy of the total ex-
pansion (see Figure 6); and
scale-based devices shall be verified periodically in accordance with Appendix B.
For all readings, the adjustable panel shall be moved so that the meniscus of the water column in the gradu-
ated burette is at the same level as the reference point indicator of the test panel.
The bottom of the water meniscus is used for all readings as shown in Figure 5.
5.3.1.2.1 Surette systems
For burette systems, all measurements shall be taken at the same reference level and from the bottom of the
meniscus (see Figure 5).
The reference point indicator should qe positioned so that measurements can be taken conveniently at eye
level. The burette assembly shall be moveable so that the water level in the burette is at the same height when
reading zero, total expansion, and permanent expansion. This water level should be above the highest point of
water in the water jacket and its connecting piping.
5.3.1.2.2 Nonburette type systems
For nonburette type systems, the EID shall be such that any change in water level does not affect the required
accuracy. The EID shall be verified periodically in accordance with Appendix B.
Nonburette type systems shall be designed to accommodate changes in water level without causing errors in
the expansion readings. ·
Pictures of typical nonburette and micro processor-based systems are found in Figures 7 and 8.
This document licensed for the sole use of the purchaser. ft may not be shared with any other person or used after the e:q>iration dale
without the express written permission of the CGA. Any unauthorized use, reproduction, di50ibution. ormod.ification ofl.kis !lrime-l ,.,~~·
will result in a $5,000 liquidated damages fee plus loss of access to CGA publications fur one year fo~'I:"-''"-- ·
- **truncated:** false
- **body characters:** 27900
