This standard specifies the shape, hole position and size of perforated paper cards. It applies to paper cards with 80 columns and 12 rows for information processing. GB/T 3908-1983 Dimensions of 80-column perforated paper cards for information processing GB/T3908-1983 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Dimensions of 80-column punched paper cards for Information processing UDC 681.827.44
1676.816.6
GH 3508—88
This standard specifies the shape, hole position and dimensions of punched paper cards (hereinafter referred to as cards). It is applicable to paper cards with 80 columns and 12 rows for information processing.
1 Definition of terms (as shown in Figure 1)
1.1 Reference line X: a straight line along the upper edge of the card. 1.2 Reference point: a point on the right edge of the card and 41.27 mm away from the reference line X. 1.8 Reference line Y: a straight line passing through the reference point and perpendicular to the reference line X. 1.4 Card "columns": 80 lines parallel to the reference straight line Y, that is, 80 columns of the card. The distance between the columns is 2.21mm. The distance between the columns and the reference straight line Y is 6.37mD.
1.5 Card "rows": 12 lines parallel to the reference straight line X, that is, 12 rows of the card. The distance between the rows is 6.35mm. The distance between the top row and the reference straight line X is 6.35mm.
Reference point
.21x79=174.59
Published by the National Bureau of Standards on October 29, 1988
SR'68 -11X 56\9
1984-1F-01 implementation
2 Dimensions and performance of the card
2.1 The dimensions of the card are shown in Figure 2. Book 95
2.2 The geometric tolerances of the card are as follows:
2.2.1 The straightness tolerance of each side is 0.08mm, GB 3908-83
Thickness 0 175-8:83
Fiber female direction
187.32 ± 0.12
2.2.2 The parallelism tolerance of each corresponding edge is 0.08mm2.2.3 The verticality tolerance of two adjacent edges is +5.2.3 The edge of the card should be smooth and free of burrs.
2.4 The physical and mechanical properties of the card paper should comply with the provisions of the Ministry of Light Industry Standard QB377-80 "Punch Cards". 3 Position and size of holes
8.1 The information code holes are all rectangular holes. The center of the hole is at the intersection of ten rows and columns (as shown in Figure 1). The long side of the hole is parallel to Y, and the short side is parallel to X. Its dimensions are:
Long side: 3.2*0.05mm,
Short side: 1.4*0.05mm. bzxZ.net
3.2 The same horizontal row The minimum edge distance between adjacent code holes should be greater than 0.51mm (as shown in Figure 3). 3.3 Since environmental changes will affect the size of paper cards (see Appendix A), when punching, the error between the center line of each hole and the row and column in the horizontal or vertical direction of the corresponding hole should be less than 0.25mm (as shown in Figure 4). 3.4 When reading, the error between the center line of each hole and the row and column in the horizontal or vertical direction of the corresponding hole should be less than 0.46mm (as shown in Figure 4).
3.5 The edge of the hole should be smooth and free of burrs.
GB3908—83
Hole center line
Less than 0.25 when punching
Less than 0.46 when reading
GB 3908—83
Appendix A
Storage and Use of Perforated Paper Cards
(Informative)
Paper cards should be stored and used under the following environmental conditions: a. Storage, relative humidity 30% to 65% and temperature 5 to 50°C. b. Use: relative humidity 40% to 60%, normal use temperature 18 to 24°C. This appendix strongly recommends that the following steps be followed. A.1 Climate Conditions
A.1.1 Importance of Climate for Cards
If proper care is not taken, cards will be affected by cold, heat, and especially humidity. Changes in humidity can cause the moisture content of the card to change, thereby changing the size and quality of the card, and can also cause the card to warp. This is the most common cause of card failure in data processing equipment.
The more obvious signs of warping are as follows: Size: When humidity increases, the card absorbs moisture, which usually makes the card longer, wider, and thicker. When the humidity decreases, the card loses moisture and the length, width and thickness will decrease. For example, a change from 20% to 75% or from 75% to 20% relative humidity will cause the length of the card to change by 0.46mm and the width to change by 0.58mm. A new card exposed to a large relative humidity change or a high relative warp environment and then returned to the initial test conditions will not return to its original size. For example, a card suddenly exposed to a relative humidity of more than 70% will cause permanent deformation and make the card exceed the tolerance range. Therefore, it is recommended to store the card at a relative humidity below 65%. b. Warp: When the card is exposed outside the relative humidity range of 40% to 60%, it may temporarily or even permanently warp. Especially under low relative humidity conditions, the lower sheet has a tendency to warp. Even if the card is kept within the limit value range, a sudden change in relative humidity can cause the card to temporarily warp. In this case, once the card reaches humidity equilibrium in the new environment, the stress causing the warping will disappear.
Note: Inherent warping of the cards may sometimes be observed, but is extremely rare. This type of warping cannot be corrected and may even be exacerbated when the cards are exposed to extreme temperatures.
However, if the cards are stored and used in accordance with the recommended environmental conditions, the dimensional changes and deformations of the cards during use will be minimal. A.1,2 Environmental conditions for work and storage areas From the above it follows:
a. The relative humidity and temperature of the work and storage areas must be taken into account and it is recommended that these data be recorded. b. For the environment in which the cards are exposed, it is desirable to keep the relative humidity constant and, in particular, to prevent sudden changes. In fact, the humidity in almost every work area can be maintained at an ideal level except when the outside temperature is extremely cold, extremely hot or the humidity is very high. Care must be taken to adjust the thermostat and humidistat. In winter, it is easier to maintain a favorable relative humidity in the machine room at a lower temperature. Continuous high heat can dry the air and can reduce the recommended humidity.
b. In summer, excessive relative humidity can be reduced by a humidifier. It must be noted that the air in a room often varies greatly, especially in pipes, heating, open windows, etc. Cards should not be stored near these places. Care must be taken when opening and closing windows. Cards should not be placed directly on the floor, especially not on non-wood floors or against walls, because localized low and high temperatures often occur in such places. The method of heating is not critical as long as the heating system used does not emit toxic gases or water vapor into the air. The following points must be taken into account:
9. Cards may warp when transporting them from the storage area to the work area, especially when there is a significant difference in relative humidity between the two areas or when the cards are not insulated during transportation. GB3908-83
b. Cards will accumulate moisture when transported from a cold room to a warm room, just like the moisture on the outside of a glass containing frozen water. A.1.3 Card Adaptation to the Environment
Even if the recommendations for card storage are followed, sufficient time should be given to the cards to allow them to reach equilibrium with the humidity of the room air before use so that they can be used normally.
The length of this time depends mainly on the relative humidity difference between the machine room and the area around the cards, the way the cards are packaged (in full cartons or in open trays, etc.), and the air circulation around the cards (open or closed cartons, etc.). Although there are no exact data, the following approximate times are given: §, one card
b. A number of cards placed in loose cartons
Relative humidity difference of ±10 degrees:
Relative humidity difference of ±2 degrees,
Relative humidity difference of ±30%:
2 hours
In any case, the carton must be allowed to reach equilibrium with the temperature of the work area before it can be opened. Where conditions permit, storage facilities that can supply 5 to 10 days of cards should be established in 1 composition. A,2 Storage steps
Cartons can protect the performance of cards. To a certain extent, cartons can reduce damage to the edges of cards and facilitate the exchange of moisture between cards and the outside world. Therefore, the storage of cards should be done as follows: a. Before use, cards should be placed in the original carton or a dedicated drawer. b. The bottom of the carton should be supported by square objects to prevent the carton from being deformed due to stacking. c. Do not place heavy objects on top of the carton.
If cartons with only half of the cards are stacked, the cards will be deformed. However, put the unfilled cartons on the top of the stack: this will prevent the cards from being easily deformed.
Properly stored cards can extend the storage life and reduce failures. From the user's best interests, it is recommended that users only store stocks that can be used for a few months. These stored cards should be used in sequence, that is, new stocks should be opened after the old stocks are used up. A, 3 Card handling
It is recommended to gently fan the cards and then feed them into the machine for stacking. The card of the feeding terminal is half-integral. If the card is slightly deformed, the operator can use it to gently push it away to restore it. Additional remarks:
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