GB/T 778.2-2018Meters for cold potable water and hot water -- Part 2: Test methods (English PDF)

Foreword

GB/T 778 "Drinking Cold Water Meter and Hot Water Meter" consists of the following five parts.

--- Part 1. Measurement requirements and technical requirements;

--- Part 2. Test methods;

--- Part 3. Test report format;

--- Part 4. Non-metering requirements not included in GB/T 778.1;

--- Part 5. Installation requirements.

This part is the second part of GB/T 778.

This part is drafted in accordance with the rules given in GB/T 1.1-2009.

This part replaces GB/T 778.3-2007 "Measurement of water flow in closed full pipes. Drinking cold water meter and hot water meter. Part 3

Points. Test Methods and Test Equipment. The main technical changes compared with GB/T 778.3-2007 are as follows.

---Modified standard name;

--- Expanded the scope of application of the standard, did not specify the maximum allowable working pressure (see Chapter 1, Chapter 1 of GB/T 778.3-2007);

--- Removed terminology (see Chapter 3 of GB/T 778.3-2007);

--- Increased the requirements for visual inspection (see Chapter 6);

--- Increased the requirement for zero flow in the static pressure test (see 7.3.3.1);

--- Removed the requirement to apply 2 times the pressure of deltap on the coaxial water meter seal in the static pressure test (see GB/T 778.3-2007)

6.4);

--- Removed the requirement that the pipe system outlet should maintain a positive pressure of 0.3 bar in the indication error test (see GB/T 778.3-2007)

5.4);

--- Removed the provisions of the error test for speed water meters (see 5.4.4.5 of GB/T 778.3-2007);

--- Increased the requirements for pressure tapping in the pressure loss test (see 7.9.2);

--- Increased the test procedure for determining the pressure loss after installation in the pressure loss test (see 7.9.3.1);

--- Increased the requirement for the test in the disturbance test for water meters that have been proven to be undisturbed (see 7.10.3);

--- Increased the requirements for the length of the intermittent flow test in the durability test and the qualification criteria for the Class 1 water meter (see 7.11.2);

--- Removed the specific test requirements for double water meters in the intermittent flow test (see 8.2.3.2 of GB/T 778.3-2007);

--- Increased the requirements for the length of the test in the continuous flow test and the qualification criteria for the Class 1 water meter (see 7.11.3);

--- Increased the requirements for static magnetic field testing of some mechanical water meters (see 7.12);

--- Added test for water meter auxiliary devices (see 7.13);

--- Increased the requirement that the water meter not marked "V" in the impact test is only tested on the horizontal axis, and the water meter with two reference temperatures is only

Requirements for testing at lower reference temperatures (see Chapter 8);

--- Modified the maximum voltage and minimum voltage applied in the DC power meter voltage test (see 8.5.3.3, GB/T 778.3-

9.5.5.4) of.2007;

--- Increased the requirements for vibration-only tests that are only suitable for mobile installation of water meters (see 8.6.1);

--- Increased the requirement that the power supply should be cut off when the device under test is in the recovery state (see 8.6.3);

--- Increased voltage interruption and reduced time interval requirements for testing (see 8.8.3);

--- Increased additional program requirements in voltage sag and short interruption tests (see 8.8.3);

--- Increase the signal line burst test (see 8.9);

--- Revised the test procedure for electromagnetic field radiation test (see 8.12.3, 9.4.2 of GB/T 778.3-2007);

--- Increased electromagnetic field conduction test (see 8.13);

--- Increased surge test of signal and control lines (see 8.14);

--- Increased zero flow test (see 8.17);

--- Increased the test content of the type evaluation (see Table 6 in Chapter 9);

--- Increased the requirements for the evaluation of the series of water meters (see 9.5);

--- Revised the water temperature range for the first test (see 10.1.3, 11.4 of GB/T 778.3-2007);

--- Increased the eligibility criteria for the first verification (see 10.1.4);

--- Increased the first verification test content of the water meter separable parts (see 10.2);

--- Revised the content of the test report (see 11.2.1, 12.1.2 of GB/T 778.3-2007)

--- Increased the type inspection and test requirements for inspection devices for electronic devices (see Appendix A);

--- Increased the requirements of the flow disturbance test device (see Appendix C);

--- Increased the requirements for type evaluation of water meters (see Appendix D);

--- Increased the content of determining the density of water (see Appendix F);

--- Increased the impact factor and the maximum uncertainty of the disturbance measurement (see Appendix G);

--- Increased the pressure loss test pressure port and the contents of the hole (see Appendix H).

This section uses the translation method equivalent to ISO 4064-2.2014 "Drinking cold water meters and hot water meters Part 2. Test methods".

The documents of our country that have a consistent correspondence with the international documents referenced in this part are as follows.

GB/T 2423.1-2008 Environmental testing of electric and electronic products - Part 2. Test methods Test A. Low temperature

(IEC 60068-2-1..2007, IDT)

--- GB/T 2423.2-2008 Environmental testing of electrical and electronic products - Part 2. Test methods Test B. High temperature

(IEC 60068-2-2.2007, IDT)

--- GB/T 2423.4-2008 Environmental testing of electrical and electronic products - Part 2. Test method test Db. alternating heat

(12h 2h cycle) (IEC 60068-2-30.2005, IDT)

--- GB/T 2423.7-1995 Environmental testing for electric and electronic products - Part 2. Test methods Test Ec and guide. Falling

With overturning (mainly for equipment type samples) (IEC 60068-2-31.1982, IDT)

Environmental testing of electrical and electronic products - Part 2. Test methods - Vibration, shock and similar

Installation of mechanical test samples (IEC 60068-2-47.2005, IDT)

--- GB/T 2423.56-2006 Environmental testing of electric and electronic products - Part 2. Test method test Fh.

Dynamic (digital control) and guidelines (IEC 60068-2-64.1993, IDT)

---GB/T 2424.2-2005 Guidelines for the assessment of damp heat in environmental testing of electrical and electronic products (IEC 60068-3-4.2001, IDT)

--- GB/T 17214.2-2005 Working conditions of industrial process measuring and control devices - Part 2. Power (IEC 60654-2.

1979, IDT)

---GB/T 17626.1-2006 Electromagnetic compatibility test and measurement technology immunity test (IEC 61000-4-1..2000,

IDT)

---GB/T 17626.2-2006 Electromagnetic compatibility test and measurement technology Electrostatic discharge immunity test (IEC 61000-4-2.

2001, IDT)

---GB/T 17626.3-2016 Electromagnetic compatibility test and measurement technology RF electromagnetic field radiation immunity test

(IEC 61000-4-3.2010, IDT)

---GB/T 17626.4-2008 Electromagnetic compatibility test and measurement technology Electrical fast transient burst immunity test

(IEC 61000-4-4.2004, IDT)

---GB/T 17626.5-2008 Electromagnetic compatibility test and measurement technology Surge (impact) immunity test (IEC 61000-4-

5.2005, IDT)

---GB/T 17626.6-2008 Electromagnetic compatibility test and measurement technology Conducted disturbance immunity of RF field induction

(IEC 61000-4-6.2006, IDT)

---GB/T 17626.11-2008 Electromagnetic compatibility test and measurement technology resistance to voltage dips, short interruptions and voltage changes

Disturbance test (IEC 61000-4-11.2004, IDT)

---GB/T 17799.1-2017 Electromagnetic compatibility common standards Immunity in residential, commercial and light industrial environments

(IEC 61000-6-1.2005, MOD)

---GB/T 17799.2-2003 Electromagnetic compatibility general standard immunity test in industrial environment (IEC 61000-6-2.

1999, IDT)

---GB/T 18039.3-2017 Electromagnetic compatibility environment common low-voltage power supply system low-frequency conduction disturbance and signal transmission

Capacity level (IEC 61000-2-2.2002, IDT)

---GB /Z 18039.5-2003 electromagnetic compatibility environment public power supply system low frequency conduction disturbance and electromagnetic transmission of signal transmission

(IEC 61000-2-1..1990, IDT)

This part was proposed by the China Machinery Industry Federation.

This part is under the jurisdiction of the National Industrial Process Measurement Control and Automation Standardization Technical Committee (SAC/TC124).

This section drafted by. Shanghai Industrial Automation Instrumentation Research Institute Co., Ltd., Ningbo Water Meter Co., Ltd., Sanchuan Wisdom Technology

Company, Ningbo Donghai Instrument Waterway Co., Ltd., Suzhou Waterworks Co., Ltd., Zhejiang Institute of Metrology, Henan Province Department of Metrology

Institute of Science and Technology, Ningbo Metrology and Testing Institute, Nanjing Water Group Co., Ltd. Water Meter Factory, Chongqing Smart Water Meter Co., Ltd., Wuxi Water

Table limited liability company, Shanghai Water Meter Factory, Shanghai Instrumentation Automatic Control System Inspection and Testing Institute, Hangzhou Water Meter Co., Ltd., Shenzhen Jiexian Digital

Technology Co., Ltd., Huizhong Instrument Co., Ltd., Fuzhou Kerong Instrument Co., Ltd., Yangzhou Hengxin Instrument Co., Ltd., Beijing Tap Water

Group Jingzhao Water Meter Co., Ltd., Jinan Ruiquan Electronics Co., Ltd., Hangzhou Jingda Electronics Co., Ltd., Jiangyin Lixin Intelligent Equipment

Company, Hunan Changde Water Meter Manufacturing Co., Ltd., Ningbo Jingcheng Technology Co., Ltd., Hunan Weiming Energy Technology Co., Ltd., Qing

Island Jicheng Electronics Co., Ltd., Tianjin Sain Energy Technology Co., Ltd.

1 Scope

This part of GB/T 778 specifies a complete water meter and a water meter measuring sensor as a stand-alone unit (including flow or volume detection elements).

And the test requirements of the calculator (including the pointing device).

This section applies to the type evaluation test and the first verification test of drinking cold water meter and hot water meter defined in GB/T 778.1.

This section gives detailed test procedures, test principles, test equipment and tests for the water meter type evaluation test and the first test.

method.

This section also applies to auxiliary devices if required by national regulations.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article.

Pieces. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 778.1-2018 Drinking cold water meters and hot water meters - Part 1. Quantitative requirements and technical requirements (ISO 4064-1.

2014, IDT)

GB/T 778.3-2018 Drinking cold water meters and hot water meters - Part 3. Test report format (ISO 4064-3.2014,

IDT)

ISO /IEC Guide 98-3.2008 Uncertainty of measurement - Part 3. Guide to measurement uncertainty indication (Uncertaintyof

measurement-Part 3. Guidetotheexpressionofuncertaintyinmeasurement)

IEC 60068-2-1 Environmental test Part 2-1. Test test A. Low temperature (Environmental testing-Part 2-1.

Tests-TestA. Cold)

IEC 60068-2-2 Environmental test Part 2-2. Test test B. High temperature (Environmental testing-Part 2-2.

Tests-TestB. Dryheat)

IEC 60068-2-30 Environmental test Part 2-30. Test test Db. Alternating damp heat (12h 12h cycle) (Environ-

mentaltesting-Part 2-30. Tests-TestDb. Dampheat, cyclic(12h 12hcycle))

IEC 60068-2-31 Environmental Test Part 2-31. Test Test Ec. rough handling impact (mainly for equipment type samples)

(Environmentaltesting-Part 2-31. Tests-TestEc. Roughhandlingshocks, primaryallyforequipment-

Typespecimens)

IEC 60068-2-47 Environmental testing - Part 2-47. Installation of test vibration, shock and similar kinetic test samples (Envi-

ronmentaltesting-Part 2-47. Tests-Mountingofspecimensforvibration, impactandsimilar

Dynamictests)

IEC 60068-2-64 Environmental testing - Part 2-64. Test test Fh. Broadband random vibrations and guidance (Environmental

testing-Part 2-64. Tests-TestFh.Vibration,bandbandrandomandguidance)

IEC 60068-3-4 Environmental testing - Part 3-4. Companion documents and guides.

Part 3-4. Supportingdocumentationandguidance-Dampheattests)

IEC 60654-2 Working conditions for control devices for industrial process measurement - Part 2. Power (Operating conditions for

industrialprocessmeasurementandcontrolequipment-Part 2.Power)

IEC 61000-2-1 Electromagnetic compatibility (EMC) Part 2. Environment Section 1. Environmental description - Low-frequency conduction in public power supply systems

Electromagnetic environment for disturbances and signal transmission (Electromagneticcompatibility(EMC)-Part 2.Environment-Section1.

Descriptionoftheenvironment-Electromagneticenvironmentforlow-frequencyconducteddisturb-

Ancesandsignalinginpublicpowersupplysystems)

IEC 61000-2-2 Electromagnetic compatibility (EMC) Part 2-2. Low-frequency conducted disturbances and signal transmissions

Compatibility level of transmission (Electromagneticcompatibility(EMC)-Part 2-2.Environment-Compatibilitylevels

Forlow-frequencyconducteddisturbancesandsignalinginpubliclow-voltagepowersupplysystems)

IEC 61000-4-1 Electromagnetic compatibility (EMC) Part 4-1. Test and measurement techniques IEC 61000-4 series standard general (E-

Lectromagneticcompatibility(EMC)-Part 4-1. Testingandmeasurementtechniques-Overviewof

IEC 610004series)

Electromagnetic compatibility (EMC) - Part 4-2. Test and measurement techniques Electrostatic discharge immunity test (Electro-

Magneticcompatibility(EMC)-Part 4-2. Testing and measurementtechniques-Electrostatic

Dischargeimmunitytest)

Electromagnetic compatibility (EMC) - Part 4-3. Test and measurement techniques - Radio frequency electromagnetic field immunity test

(Electromagneticcompatibility(EMC)-Part 4-3. Testingandmeasurementtechniques-Radiated,

Radiofrequency,electromagneticfieldimmunitytest)

Electromagnetic compatibility (EMC) - Part 4-4. Test and measurement techniques - Electrical fast transient/burst immunity test

Test (Electromagneticcompatibility(EMC)-Part 4-4. Testingandmeasurementtechniques-Electrical

Fasttransient/burstimmunitytest)

Electromagnetic compatibility (EMC) - Part 4-5. Test and measurement techniques - Surge immunity test (Electromag-

Neticcompatibility(EMC)-Part 4-5. Testingandmeasurementtechniques-Surgeimmunitytest)

Electromagnetic compatibility (EMC) - Part 4-6. Test and measurement techniques

(Electromagneticcompatibility(EMC)-Part 4-6. Testingandmeasurementtechniques-Immunityto

Conductivedisturbances,inducedbyradio-frequencyfields)

Electromagnetic compatibility (EMC) - Part 4-11. Test and measurement techniques, voltage dips, short-term interruptions and voltages

Variable immunity test (Electromagneticcompatibility(EMC)-Part 4-11. Testingandmeasurementtech-

niques-Voltagedips, shortinterruptionsandvoltagevariationsimmunitytests)

IEC 61000-6-1 Electromagnetic compatibility (EMC) Part 6-1. General standard Immunity in residential, commercial and light industrial environments

Test (Electromagneticcompatibility(EMC)-Part 6-1. Genericstandards-Immunityforresidential,

Commercialandlight-industrialenvironments)

Electromagnetic compatibility (EMC) - Part 6-2. Immunity test in general standard industrial environment (Electro-

Magneticcompatibility(EMC)-Part 6-2. Genericstandards-Immunityforindustrialenvironments)

OIMLD11.2004 General requirements for electronic measuring instruments (Generalrequirementsforelectronicmeasuringin-

Struts)

Planning of the OIMLG13 Metrology and Testing Laboratory (Planningofmetrologyandtestinglaboratories)

3 Terms and definitions

The terms and definitions defined in GB/T 778.1-2018 apply to this document.

4 Reference conditions

When performing a type evaluation test on a water meter, in addition to the amount of influence to be tested, all applicable influences shall maintain the following values.

However, for electronic water meters, the influence factors and disturbances allow the use of the reference conditions specified in the corresponding standards.

Flow rate. 0.7 x (Q2 Q3) +/- 0.03 x (Q2 Q3)

Water temperature. T30, T50. 20 °C +/- 5 °C

T70~T180. 20°C+/-5°C; 50°C+/-5°C

T30/70~T30/180. 50°C+/-5°C

Water pressure. rated working conditions (see 6.4 of GB/T 778.1-2018)

Ambient temperature range. 15 ° C ~ 25 ° C

Relative humidity range. 45%~75%

Ambient air pressure range. 86kPa~106kPa (0.86bar~1.06bar)

Power supply voltage (AC power supply). Nominal voltage (Unom), tolerance +/- 5%

Power frequency. nominal frequency (fnom), tolerance +/- 2%

Power supply voltage (battery). A voltage V within the range of Ubmin <= V <= Ubmax

The temperature and relative humidity changes within the reference range should not exceed 5 ° C and 10%, respectively, during each test. If type approval machine

The structure can obtain evidence that the test water meter type is not affected by the deviation of the conditions under consideration, and the reference conditions are allowed to deviate during the performance test.

The tolerance value is specified, but the actual value deviating from the reference condition should be measured and recorded in the performance test file.

5 symbols, units and formulas

The formulas, symbols and their units used in this part to calculate the error of the water meter (indicator) are shown in Appendix B.

6 Visual inspection