Do you know the test functions of a variety of human ground testers
In the daily electronic production site, there are often feedbacks that the static voltage on the employees in the workshop is very high. I don't know where the problem is. How can the static electricity on the human body be removed? ANSI/ESD S20.20 stipulates that the resistance of the stalk and floor system is less than 1-109Ω, and the electrification voltage is less than 100V peak when people wear anti-static shoes while walking on the floor. The anti-static wrist strap must be used by people who operate the SSD. When using the wrist strap, what should theoretically be a good contact between the wrist strap and the human wrist, the ground connection wire and the ground wire, the wire resistance is 0.8*106Ω; the ground resistance when wearing is less than 3.5* 107Ω. When using a wrist strap, make sure that the grounding must be firm and the contact resistance is small. The diameter of the grounding metal core of the wrist strap should be greater than 1.5 mm2, and the elastic band must contain conductive wires.
To do a good job of human body static electricity protection, we must go through strict technical checks. At present, the most used by customers is to install a comprehensive human body static detector with an access control system at the door of the workshop. Only when the static protection reaches the standard, the barrier will open the door for employees to enter the workshop. , How to choose a human grounding tester suitable for workshop use?
Introduction to the functions of the human body comprehensive measuring instrument
One: What is the function of the human body grounding tester?
There are many names for the human body grounding tester in the market, such as the human body comprehensive tester or the wrist strap/anti-static shoe tester, which actually refers to the same kind of instrument. This type of instrument is installed at the entrance of the electrostatic protection zone (the entrance of the workshop),
Check whether the resistance of employees wearing anti-static wrist straps and work shoes is within the qualified range. Only qualified employees can enter the electrostatic protection area (EPA).
2: What is the difference between a human body grounding tester and a real-time grounding monitor?
The human body grounding tester is mainly installed at each door point, and only qualified employees are allowed to enter. It is usually used in conjunction with the access control. The real-time grounding monitor is installed in a fixed workstation to monitor the grounding status of the human body, table tops and equipment in real time. for
Moving personnel cannot use real-time grounding monitors, and moving personnel are grounded through anti-static shoes, so they can only be detected by a human body grounding tester.
Three: What is the difference between a human ground tester and a wrist strap tester?
The wrist strap tester detects whether the resistance of the wrist strap itself is qualified, and the human body ground tester detects whether the resistance of the human body to the ground through the wrist strap is qualified, so the human body ground tester tests the resistance of the human body + the resistance of the wrist strap.
Four: What are the operating precautions for the human body grounding tester?
Pay attention to the following matters to avoid damaging the instrument and causing confusion in use:
1) The tester itself must be reliably grounded: the static electricity generated by the human body may be introduced into the internal circuit board of the instrument through the fingers. If the tester is not grounded or the grounding is unqualified, the internal chip may be burned.
2) Keep the test button dry and free of pollutants, otherwise there is a risk of forming a short circuit
3) The resistance of anti-static shoes may change due to different weather temperature/humidity or pollution levels, sometimes qualified and sometimes unqualified. This is not a tester problem, but the resistance of the anti-static shoes itself.
Five: How to calibrate the human body grounding tester?
After the tester is installed, it is not easy to remove it, so it is not very convenient to send the instrument to a third party for calibration. It is recommended to buy the original standard resistance box, first calibrate whether the standard resistance box is qualified, and then use the qualified standard resistance box in
The human body grounding tester can be calibrated at the actual location, which is a simple and efficient way.