Sunday, April 3, 2011
Weak current College】 【anti-static knowledge (4)】.
<br> <br> 31: we have a three-phase four-wire AC system of old buildings, equipment and electrical metallic tubes connected to neutral, while enabling protective duct buildings. We can add the catheter as ESD grounding? or do we .need to install a separate ESD system grounding system? <br> A: Yes, you can use catheter as ESD grounding. ESD grounding wire or "public" grounded's main purpose is to create a "public place", or in order to eliminate the .potential difference between the conductor, the key work areas in which all conductors and equipotential bonding public. Once the conductors of electric potential difference is eliminated, these conductors produce ESD capacity will be reduced to a minimum. Even in the workspace all conductors are grounded, .you still face the risk of ESD. Because the external conductor will still be on ESD grounding of electric potential difference, thus generating ESD grounding conductor. This includes feeding members (without ground) to you (ground) to send parts, IC chips from protection .tube to the ground floor, circuit board mounting bracket in a conductor, and so on. <br> <br> 32 q: is only exposed to normal living environment floor mat, were covered with dust, the how to clean it? (this .does not include invites qualified professionals for cleaning and testing) <br> A: what methods should be taken to clean the ESD floor mat depends on your control plan. Suppose you have a very strict control scheme, ESD floor mat specifications to 106-109 ., 25 were moving back and forth. In this case, it is best to every night dry cleaning (sweep) floor mat to clear the dust (this will increase the insulation and wear), cleaning at least once a week. You can make adjustments .according to the specific plan. It is best to control scheme in the allowed range, the measurement every day and make the appropriate chart, on the basis of these data you can fix a clean floor mats with appropriate cycle. <br> <br> .33: the role of about overalls are not very clear to me. My company's staff believe that if you took the Bowl sets, work clothing is superfluous. This is because the human body or clothes will charge, through the discharge wrist set to land. .<br> Answer: this question asked so well. This is a common misconception. Most of the clothes is insulated or insulation performance (depending on how much of a sweat in the clothes, the thickness, cloth, layers, etc.). Charge .on the insulator is not moved, it will remain on the insulator, after a certain period of time (usually a few hours or days), or in and out and air ions neutralize (artificial intervention time can be reduced to a few seconds). .Therefore, your sleeve, belts and other possible with few kV voltage (it generates electric field for purposes of conducting around is very strong), which may cause the nearby isolation of conductor induces charge on. Therefore staff members need to wear the uniform, ESD .will insulated clothing shield to make clothes produced by mechinical. Be aware that we must put your sleeve into the overalls. <br> <br> 34 asked: I need the circuit board components from a grounded stage to a grounding in the wave soldering machine ., but I didn't do the conductive wax or floor mat. The distance between the two to 20 feet. Component in welding must be horizontally and shipping. In order to enable the operator to transfer these parts, I can mount the components of the .car isolation? <br> A: Don't isolate these carts. If you drop a component on the loss of the airtight container (such as removal boxes), then you don't need to push the car received a conductive / loss of .the floor, although it is best to do so. During transportation, loss of airtight container can make its internal potential at the same level (that is, the Elimination of minimum or discharge). Before opening, suitcase required in a lossy grounding mat, .eliminate the potential difference between the so and with anti-static wrist set of operators in the same potentials. <br> <br> 35: my company a division of conductive floor performance almost out, I asked them how to clean the floor, they .said that the use of softness cleanser rather special detergents. My question is, is there a special cleanser? <br> A: the softness of residual detergent can be caused under the insulation material conductive floor not qualified. There are special conductive floor cleaner, .do not leave residual insulation material. But for some conductive floor, cleaning with water is sufficient. <br> <br> 36: electrostatic charge in the printing industry is a common problem. Paper through the press, will take charge. When the same .paper sent back from the press box, the paper has taken on many of the charge so that paper are stuck together. On the how to solve this problem? <br> A: whenever one object with another object's surface contact and separation, in both .surface-induced charge imbalance, resulting in a static charge (electrostatic field). Industrial ionization is the solution to this problem. This is in the vicinity of a surface (0.5 - 2 inches) using ion beams so that the surface is surrounded by a .large number of positive ions. Essentially, this process only surface on one side of the occurrence of electrostatic charge and, thereby reducing the induction charge. On both sides of the paper are using ion beams to maximally reduce static electricity. In General be in the .objects and separation after it uses electrostatic ion beam, in particularly serious, should first be ion process. <br>? <br> 42. q: guarantee safe ESD flooring is the proper way? only uses electrostatic dissipation wax? <br> A .: use anti-static floor coating loss (wax typically insulation) is the floor a good beginning of electrostatic safety. In order to improve safety flooring electrostatic discharge system, must be equipped with anti-static shoes or static grounded foot, car or swivel chair .on pulling, the entrance of electrostatic discharge warning signals (for staff wear uniforms for ESD shoes) and electrostatic discharge a security zone, optional distinguish between electrostatic discharge floor flooring adhesive tape. You also need to follow the manufacturer regarding the application and maintenance instructions. .Anti-static floor about the technical details, including the application and maintenance can be found in the PDF format. We propose to least 60 square feet of floor finishing agent to correctCoupled to the Earth (its role as a big capacitors), thereby reducing the .charge does not balance to zero, but also require at least three layers of finishing agent to obtain the correct floor impedance range (109/square) (that is, the more thick plate, the derivation of the better). <br> <br .> 43. q: indoor carpet a few benches, I can do some ESD mat and earthing bar? <br> Answer: assuming that the carpet insulation and antistatic, indoors, ESD mat and grounding bars to protect workstations, workspace, it should remain .at least 3 feet or so. In addition, the storage of ESD sensitive devices, bench top and ESD grounding pad should be used for protection. To ensure that ESD mat with loss, so that they would not give rise to electrostatic discharge. This depends .on the person walking on the mat, the frequency of each employee in the feet and a wrist (or overalls) use the grounding bars. Minimum protection (once the floor and bench cushion paved) is in front of the bench with anti-static wrist .and public Earth point. Simple and convenient (for play <br> See). <br> <br> 44. q: in order for two test electrodes measure or calculate the peak discharge energy levels, you need to use high-speed oscilloscope .. If you want to store 100-coke or higher energy, capacitance value limits the scope in order to obtain accurate? the readings, the frequency of using 500kHz fast enough? <br> A: two and charging device model depends on the proximity of .metal electrode response between, its discharge power rise time is less than 200 leather seconds. This response to electromagnetic pulse form be high-speed oscilloscope input of dipole antenna receives, in order to accurately observe it, at least two signal response or 10GHz oscilloscope. .<br> <br> 45. q: there are a lot of electrostatic discharge (ESD wrist monitor model A98200). The anti-static wrist monitor calibration you want? how do you calibrate it? useful to the calibration of the instrument it? .if so, how much money you probably will not calibrate?? <br> A: typically use cases should be calibrated once each year. <br> <br> 46, question: in the absence of electromagnetic pollution room (100 level), .through the floor mat for electrostatic discharge protection. Have suggestions on this? <br> Answer: it is recommended that you use the model L blue or white cushion materials used to clean house. Model L-blue material with electrical losses, direct sale, .feet width 2 ft. <br> <br> 47. q: printing plant in air relative humidity control at 50%. Operation workers whenever a touch device, such as door handles things like any metal objects, they will feel a numbness. Separate .floor cushions are sufficient to protect against electrostatic? anti-static shoes or anti-static wrist, to use it? <br> A: there are two likely causes are operatives were on the metal conductor electrostatic discharge. One is caused by walking triboelectrification; .another is because clean housing coating resulting frictional electricity. Objects not balance the accumulation of electric charges, in contact with and separation when it produces friction electric, which in turn caused significant electrostatic discharge phenomena. In order to reduce the first question, the nature with .special antistatic floor cushions of electrostatic discharge. ESD floor finishing systems such as zinc-free anti-static floor finishing agent. Anti-static floor finishing agent system has excellent antistatic characteristics, are not allowed to charge more than 100V friction. <br> In .order to reduce the second issue, let the operator put on cotton clothes instead of rayon, nylon, silk, wool, etc. In order to reduce friction and charging of the human body, clean housing coating. Put on electrostatic discharge clothes has many advantages ., starting from quarantined between different substances, some anti-static material may cause a charge. You can also try using different material consisting of floor coatings, because the formation of the current indoor coating material in the frictional electrification sequence table at a high level ( .down or down). <br> In short, a correct body grounding (with anti-static wrist and foot grounding of ESD flooring) to effectively eliminate the problem. <br> <br> 48. q: ESD safe workstations accepted standards is .them? that is, all objects of a workstation is lower than the voltage 100V or other potential? this request specific standards set out in what? <br> <br> A: safe ESD safe workstation based products play a role of sensitivity. For .some users this may be a 200V, while other users may refer to 20V! producers of related data elements <br> <br> 49. q: we are developing the same machine, which has a large video monitor. Its glass Windows surface electrostatic .field, occasionally causing small Sparks, and quickly jump to metal parts for constitutes, also in contact with the metal parts of human body sparks. There is no simple solution to this problem, such as a grounding, etc? <br> A: the .glass Windows surface is charging to high potentials, the reason for this is most likely the inner surface of high energy electron collision. This high potential to produce very high electric field, the leakage power moves. Ground will be very beneficial to the outer surface of .the glass Windows with a conductive material covering, and at the same time its grounding, this will reduce the accumulated net charge to a very low level. You can try the electrostatic discharge system, on glass exterior electrostatic dissipation, and its surface to ground ( .it can be braided guided RIP 1 / 4 inches, and the side of the glass is attached to the side or corner). <br> <br> 50. q: How do I handle one-time ESD grounding bars? <br> .A: the one-time anti-static wrist grounding wire instructions for use are as follows: <br> 1. in the processing before the electrostatic sensitive components should wear anti-static wrist. <br> 2. open the grounding bars starting of .12 inches, Peel the protective layer to the right length, so that it can match with your wrist is very good. The exposed parts at the same time firmly <br> Paste to your wrist. <br> 3. extract the grounding bars completely .stripped from the end of the 4-inch layer of protection, the exposure of viscose and attached to the surface and electrical. <br> <br>.