test point 1 Labor intensity grading (high frequency test point)
test point 2 Comparison of advantages and disadvantages of people and machines (high frequency test point)
(I) Information reception
When the machine accepts physical factors, the detection metric range is very wide and can correctly detect electromagnetic waves , infrared or other electromagnetic waves.
(II) Information processing
machine can work quickly and accurately if it is pre-programmed. The memory is correct and can be stored for a long time, and the retrieval speed is fast; it is highly reliable; it is superior to humans for processing liquids, gases and powdery bodies, but it is not as good as humans for processing soft objects; it can perform calculations correctly, but it is difficult to correct errors; it has weak graphic recognition capabilities.
(III) Information exchange and output
machine can output extremely large and extremely small power, but in most cases it is not as good as manual labor; the purpose of some special machinery cannot be changed, it can only operate according to the program and cannot adapt to the situation.
(IV) Learning and Induction abilities
The robot has poor learning ability and poor flexibility. It can only understand specific things, and the decision-making method can only be determined through pre-programming.
(V) Reliability and adaptability
can operate continuously, stably and for a long time, monotonous repetitive work without fatigue and boredom; high reliability, powerless against unexpected events; not prone to errors, and once errors are made, it is not easy to correct.
(VI) Environmental adaptability
can adapt to poor environments and can work reliably in harsh and dangerous environments such as radioactive, toxic gases, dust, noise, darkness, strong storms, etc.
(7) Cost
Machinery and equipment investment is high at one time; but the operating cost within the life span is lower than the labor cost.
test point 3 types of human-machine system (intermediate frequency test point)
human-machine system can be divided into three types according to the degree of automation of the system: manual operating system, semi-automated system and automation system.
1. Semi-automated system: People mainly act as operators and controllers of the production process in the system. Safety mainly depends on the rationality of human-machine function allocation, the inherent safety of the machine and human error conditions.
2. Automation system: with the machine as the main body, the person is just a monitor and manager. The safety of the system mainly depends on the inherent safety of the machine, whether the redundant system of the machine fails, and the situations of the person being at low load, etc.
Electrical safety technologyElectrical accidents and hazards
test point 1. Electric shock type (required test point)
1) According to the state of the electrical equipment when an electric shock occurs, it is divided into:
① Direct contact with electric shock: touching the charged body that is charged under normal conditions (such as: accidentally touching the terminal );
② Indirect contact with the motor: touching the charged body that is not charged under normal conditions and accidentally charged under fault conditions.
2) According to the way the human body touches the charged body and the way the current flows through the human body, electric shock can be divided into single-line electric shock, two-line electric shock and step voltage electric shock.
2. Electrical injury
(1) Arc burn - Arc burn is an burn caused by arc light discharge, and is the most dangerous electric injury.
(2) Current burn—current burn is the damage caused by the conversion of electric energy into heat through the human body. It usually occurs on low-voltage electrical equipment .
(3) Skin metallization
(4) Electromagnetic
(5) Electrical and mechanical damage (6) Electric flash
Test point
Effect of the human body
1. Small currents of tens to hundreds of milliamps, the most dangerous reason for making people fatal in a short period of time through the human body is to cause fibrous ventricular tremors. The heart trembles more than 21,000 times per minute , and breathing may last 2-~3min.
2.50Hz is the frequency that people are most exposed to, and it is also the most dangerous frequency for electric shock;
3. This section of the current refers to the 50Hz power frequency current, and the values mentioned refer to the effective value.
4. Effect of current size
