This standard specifies the technical requirements, test methods, inspection rules, etc. for ammeters used in construction machinery. This standard applies to electromagnetic ammeters that indicate the charge and discharge status of batteries in construction machinery, and other motor vehicle ammeters can also refer to it. JB/T 7696.4-1995 Ammeters for Construction Machinery JB/T7696.4-1995 Standard download decompression password: www.bzxz.net

Machinery Industry Standard of the People's Republic of China
JB/T7696.1~7696.4-95
Instruments for Engineering Machinery
Published on June 20, 1995bzxz.net
Ministry of Machinery Industry of the People's Republic of China
Implementation on January 1, 1996
Mechanical Industry Standard of the People's Republic of China
Ammeters for Engineering Machinery
1 Subject Content and Scope of Application
This standard specifies the technical requirements, test methods, inspection rules, etc. for ammeters for engineering machinery. JB/T7696.4-95
This standard applies to electromagnetic ammeters that indicate the charge and discharge status of batteries for engineering machinery. Other ammeters for motor vehicles can also be implemented as a reference.
2 Reference standards
GB2828
JB/T7696.1
ZBT35001
3 Technical requirements
3.1 Basic parameters
Batch inspection counting sampling procedures and sampling tables (applicable to continuous batch inspection) Pressure gauges for engineering machinery
Basic technical conditions for automotive electrical equipment
The ammeter shall comply with the requirements of this standard and shall be manufactured according to the drawings and design documents approved by the prescribed procedures. 3.2 Units and divisions
The measurement unit of the ammeter is expressed in ampere (A), and four divisions are specified in principle: negative upper limit value - negative middle value - zero - positive middle value - positive upper limit value.
3.3 Standard environment
Relative humidity
1828℃
45%~75%
86~106kPa
3.4 ​​Working environment temperature
The working environment temperature of the ammeter is shown in Table 1.
Storage humidity
40~+70
3.5 Appearance
The protective layer should be evenly coated without obvious defects such as bubbles, spots, rust and shedding. 3.5.1
Glass and other transparent materials should not have scratches and refraction that affect accurate readings. 3.5.2
The graduation lines, symbols, numbers and other marks on the dial must be clear and complete. The exposed part of the ammeter should not have a strong glaring luster. 3.5.4
When the ammeter is not working, its pointer should be within the zero graduation line. 3.5.5
3.6 Paint and plating
Approved by the Ministry of Machinery Industry on June 20, 1995
Working temperature
20~+ 55
Implemented on January 1, 1996
JB/T 7696.495
3.6.1 In addition to meeting the requirements of Article 4.5.1 of this standard, the paint layer should have a bright surface color, be firmly bonded to the surface of the covering, and not shrink or peel after the temperature resistance test. 3.6.2 The electroplating layer and chemical treatment layer should meet the relevant requirements of ZBT35001. 3.7 Performance
3.7.1 Movement state of movable part
The movable part of the ammeter should be balanced. When the current changes steadily, the pointer of the ammeter should move steadily without obvious jumping or jamming.
3.7.2 Basic error
The basic error of the ammeter under standard conditions shall not exceed ±7.5% of the sum of the absolute values ​​of the two upper limits of the scale. 3.7.3 Response time of the pointer
When the pointer of the ammeter moves to the upper limit of the scale, cut off the power supply and the pointer must stop swinging within 3s. 3.7.4 Overload
Ammeters with an upper limit current value of less than 50A on the scale shall be able to withstand an overload test of three times the upper limit current value and 0.5s of power on. Ammeters with an upper limit current value of equal to or greater than 50A on the scale shall be able to withstand an overload test of twice the upper limit current value and 0.5s of power on. After the test, it shall comply with the provisions of Articles 3.7.1 and 3.7.2 of this standard. 3.7.5 Voltage resistance
The indicator of the electrical ammeter shall be able to withstand a voltage of 550V with an actual sine waveform of 50Hz for 1min, and its insulation shall not be broken down. In large-scale continuous production, it is allowed to use a test with a voltage of 660V and a duration of 1s instead. 3.7.6 Temperature influence
When the ammeter is subjected to the temperature influence test according to the working environment temperature range, the absolute value of the change in its indication value caused by this test should not exceed 5% of the sum of the absolute values ​​of the two upper limits of the scale.
3.7.7 Humidity and heat resistance
The ammeter should be able to withstand the alternating humidity and heat test with a high temperature of 40℃ and a cycle of 6 days. After the test, it should be able to meet the requirements of Articles 3.7.1 and 3.7.2 of this standard.
3.7.8 Vibration resistance
The ammeter should be able to withstand the fixed-frequency and swept-frequency vibration tests in the three directions of up and down, left and right, and front and back. The test specifications should meet the requirements of Table 2, Table 3 and Table 4.
3.7.8.1 First, measure the resonance point according to the requirements of Table 2. Table 2
Vibration frequency
Sweep cycle
Acceleration
3.7.8.2 If there is no resonance point, conduct vibration endurance test according to the provisions of Table 3. Table 3
Vibration frequency
Acceleration
Test time h
Full frame
0.4 or less
3.7.8.3 If there is a resonance point, conduct vibration test for 1h up and down, 0.5h left and right, and 0.5h front and back according to the resonance point and the full vibration as shown in Figure 1, and then do the test specified in Table 4.
Reporting rate
JB/T7696.4-95
16. 7 33. 3 65. 7 166.7 833, 4 666.8Reporting rate
Reporting acceleration
Test timeh
After the vibration test, the parts of the ammeter should not be loose or damaged. The absolute value of the change in the indicated value shall not exceed 7% of the upper limit pressure value of the scale, and shall comply with the requirements of Article 3.7.1 of this standard. 3.7.9 Durability
The ammeter shall be able to withstand 30,000 cycles of alternating current testing. After the test, the change in the indicated value shall not exceed 5% of the sum of the absolute values ​​of the two upper limits of the scale, and shall comply with the provisions of Article 3.7.1 of this standard. 3.7.10 Dustproof performance
After the dustproof test, the ammeter shall not have dust that affects the reading, and shall comply with the provisions of Articles 3.7.1 and 3.7.2 of this standard. 3.7.11 Water resistance
After the water spray test, the inner surface of the glass of the ammeter shall not be water-permeable, and shall comply with the provisions of Articles 3.7.2 and 3.7.5 of this standard. 4 Test method
4.1 Appearance inspection
During the appearance inspection, the visual inspection shall be carried out under a uniform illumination of 300lx and an eye distance of 500mm. 4.2 Inspection of paint and plating layer
4.2.1 The appearance quality of the paint layer shall be inspected by visual inspection. 4.2.2 The adhesion of the paint layer shall be inspected by the grid method on the fully dried paint surface, that is, four lines are cut vertically and horizontally with a No. 11 or No. 12 medical surgical blade, with a spacing of 1mm between each line, to form 9 squares, and observe whether the layers in the squares have delamination. 4.2.3 The temperature effect performance of the paint layer shall be inspected after the temperature effect test. 4.2.4 The alternating damp heat performance of the paint layer shall be inspected after the alternating damp heat test. 4.2.5 The quality of the electroplating layer and the chemical treatment layer shall be inspected by the method specified in Article 4.12 of ZBT35001. 4.3 Performance test
4.3.1 Test conditions
JB/T 7696.4-95
4.3.1.1 When inspecting the indication value of the ammeter, it shall be carried out under the standard environment specified in Article 4.3 of this standard. 4.3.1.2 The installation position of the ammeter on the test bench should be the same as the actual installation position in the vehicle model. 4.3.1.3 The accuracy of the standard ammeter shall not be less than Class 1.5. 4.3.1.4 The accuracy of the standard thermometer shall not be less than ±1℃ 5.3.1.5 Except for the test of changing the indicated value reading and the perturbation test, the other test items of the ammeter are in the non-operating state. 4.3.2 Pointer response test
Record the time it takes for the pointer of the ammeter to return to the zero position from the upper limit of the scale when the power is cut off. The average time measured in three tests should be taken.
4.3.3 Basic error test
First check the balance of the movable part. When the ammeter is tilted 90° to the left and right from the specified working position, the axis of its pointer is located within the range of the equal division lines. Then use the method of comparing with the standard ammeter to check all the division lines of the ammeter except the zero division line in the order of positive first and negative later.
4.3.4 Overload test
Connect the ammeter to the circuit with the current value specified in Article 3.7.5 of this standard for 1s. The test current is conducted in either direction only. After the test, check its performance according to the method specified in Article 4.3.3 of this standard. 4.3.5 Withstand voltage test
The withstand voltage test of the ammeter shall be in accordance with JB/T7696.4.3.6 Temperature influence test
The temperature influence test of the ammeter shall be carried out in accordance with the provisions of JB/T7696.1. 4.3.7 Alternating damp heat test
The alternating damp heat test of the ammeter shall be carried out in accordance with the provisions of JB/T7696.1. 4.3.8 Vibration test
The vibration test of the ammeter shall be carried out in accordance with the provisions of JB/T7696.1. 4.3.9 Durability test
The ammeter shall be installed in the vehicle model, engine or test bench in the normal working position, and the ammeter shall be given a cyclic current change of 15 to 30 times per minute. Each cycle shall make its indication value change from zero to one third of the current value of the upper limit of the scale, and then return to zero. This shall be carried out 30,000 times in total. During the test, the visual inspection method shall be used to check whether there are any abnormalities in its various parts. After the test, the performance shall be inspected by the method specified in Article 4.3.2 of this standard. 4.3.10 Dustproof test
The dustproof test of the ammeter shall be carried out in accordance with the provisions of JB/T7696.1. 4.3.11 Water resistance test
The water resistance test of the ammeter shall be carried out in accordance with the provisions of JB/T7696.1. 5 Inspection rules
5.1 Factory inspection
5.1.1 The ammeter shall be inspected and qualified by the inspection department of the manufacturer before it can be shipped. The inspection items include 3.5, 3.7.1, 3.7.2, 3.7.3, 3.7.4 and 3.7.5.
5.I.2 The factory inspection shall be carried out in accordance with the provisions of GB2828, using a normal inspection one-time sampling plan, the general inspection level I, and the inspection batch size is generally 91150. The qualified quality level shall be determined in accordance with the provisions of Table 5 or by negotiation between the supply and demand parties. 25
Inspection.
JB/T 7696.495
Inspection items
Moving state of moving parts
Basic error
Overload performance
Withstand voltage performance
Response time of pointer
Surface quality
In the inspection, if the number of unqualified items in each item is equal to or less than the corresponding qualified judgment number A., ​​then accept the batch of products, otherwise, piece by piece 5.2 Type inspection
The ammeters for type inspection shall be extracted from the same batch of ammeters that have passed the factory inspection, and the number of extracted shall not be less than 9. First, re-inspect according to the factory inspection items. After re-inspection, the products shall be evenly divided into 3 groups. 5.2.2
The items for inspection of each group shall be in accordance with the provisions of Table 6.
First phase
Water resistance
Dust resistance
Second group
Temperature influence test
Operation test
Moisture and heat resistance
Coating and coating inspection
Third phase
Durability test
5.2.3 If one item fails in the test, it is allowed to re-sample a larger number of products and re-check the failed item. If there are still unqualified items, the batch of products will be judged as unqualified. 6
Marking, packaging, transportation and storage
Each ammeter should be marked with the manufacturer's name, product model and rated working voltage. Each ammeter shall be packed with plastic film and then packed in a foam packaging box. The outer surface of the packaging box shall be marked with: a.
Manufacturer name and address;
Product name, product model:
Quantity and year and month of production.
6.3Put the packaging box in a packaging box with protective fillings. The outer wall of the packaging box shall be marked with: a.
Name and address of the consignee:
Product name, specifications and quantity:
Name and address of the consignor;
Anti-pressure, anti-vibration, anti-drenching, handle with care and other marks. 6.4The documents accompanying the packaging shall include the product factory certificate and product manual. 6.5 The packaged ammeters should be placed in a ventilated and dry room. The storage period is one year (calculated from the date of entry into the warehouse by the manufacturer). When the storage period expires, the ammeters should still comply with the provisions of this standard. 26
Warranty period
JB/T7696.495
If the ammeter is damaged or cannot work normally due to poor manufacturing within 12 months from the date of delivery (based on the date of the delivery invoice) under normal use and maintenance conditions by the user, the manufacturer shall be responsible for free repair or replacement. Additional remarks:
This standard was proposed and coordinated by the Tianjin Engineering Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Guanjin Engineering Machinery Research Institute of the Ministry of Machinery Industry and Shanghai Oriental Instrument Factory. The main drafters of this standard are Yang Chengshan and Zhuo Liwei. 27495
If the ammeter is damaged or fails to work properly due to poor manufacturing within 12 months from the date of delivery (based on the date of delivery invoice), the manufacturer shall be responsible for free repair or replacement. Additional remarks:
This standard was proposed and managed by Tianjin Engineering Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Guanjin Engineering Machinery Research Institute of the Ministry of Machinery Industry and Shanghai Oriental Instrument Factory. The main drafters of this standard are Yang Chengshan and Zhuo Liwei. 27495
If the ammeter is damaged or fails to work properly due to poor manufacturing within 12 months from the date of delivery (based on the date of delivery invoice), the manufacturer shall be responsible for free repair or replacement. Additional remarks:
This standard was proposed and managed by Tianjin Engineering Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Guanjin Engineering Machinery Research Institute of the Ministry of Machinery Industry and Shanghai Oriental Instrument Factory. The main drafters of this standard are Yang Chengshan and Zhuo Liwei. 27
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