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What Are Cartesian Robots?

Cartesian Robots, also known as gantry robots, operate by moving along two or three orthogonal axes. Their straightforward structure makes industrial robots a common choice for automating various tasks across a wide range of industries.

Since they have at most three Cartesian coordinates, they can be made by hand and can be easily modified. Another feature is that the program that performs the work can be easily modified.

Therefore, if the work does not require complicated motions and involves monotonous movements, Cartesian Robots can be used to mechanize the work relatively easily.

Applications of Cartesian Robots

Cartesian Robots are mainly used in the manufacturing industry for simple tasks such as assembling and transporting parts. In this field, Cartesian Robots are often introduced because linear motion is sufficient to perform these tasks.

First, the line along which the parts will flow is determined. Then, by using a camera or other means, the work from assembly to transport is broken down and replaced by Cartesian Robots. The introduction of the system enables stabilization of productivity.

Specifically, Cartesian Robots are used for small precision mechanical parts, automotive parts, electronic parts for board mounting, as well as in the medical and pharmaceutical fields. In the food field, for example, specially processed arms can precisely grip and move delicate foods, such as tofu, which is fragile and difficult to handle.

The operating range of Cartesian Robots is simple and easy to understand compared to, for example, robots with 6-axis motion, and the price is favorable. Cartesian Coordinate Robots can be used stably even under severe conditions, such as in humid places or semiconductor factories where corrosive gases are used.

Principle of Cartesian Robots

The basic operation of Cartesian Robots is to slide a work arm along a linear guide to perform tasks such as assembly, transportation, and positioning.

Multiple units that move on a single axis are combined to perform work in a Cartesian coordinate system. In this case, since each axis of the robot can be moved simultaneously, many operations can be performed efficiently by superimposing linear movements.

Features of Cartesian Robots

1. High Degree of Freedom in Combination

Cartesian Robots have a relatively narrow operating range, but they can be combined with a high degree of freedom and can be easily adapted to the required specifications. Since their movements are simpler than those of other robots, they are easier to control, and it is possible to combine multiple Cartesian Robots.

By combining and coordinating with other robots, it is possible to perform many tasks, such as making some complex movements or incorporating processes such as material cutting

2. High Accuracy

Cartesian Robots can only perform simple linear movements, but the accuracy is higher. In particular, those using linear guides with ball screws and linear encoders can achieve highly accurate positioning.

3. High Rigidity

Cartesian Robots have fewer parts, which makes them more rigid. As a result, gaps and deformation are minimized, motion blur is reduced, and work is stabilized. In addition, the simple structure of the Cartesian coordinate robot allows for faster speeds and shorter cycle times.

4. Low Cost

Cartesian Robots, which can be manufactured with a simple structure and a small number of parts, are less expensive than articulated robots.

Other Information on Cartesian Robots

1. Disadvantages of Cartesian Robots

Cartesian Robots have disadvantages as well as advantages.

Complex work is impossible
It is difficult to perform complex tasks other than the combination of linear motion.

Large footprint
The disadvantage of Cartesian Robots is  that they tend to have a large footprint because they can only move in a straight line and cannot be folded because they have no joints.

Difficult to enlarge
It is difficult to make Cartesian Robots larger in size while maintaining their accuracy and strength, due to cost.

2. Examples of Cartesian Robots

Manpower saving in conveyance work
Although an articulated robot was used to automate the conveyance of change after packaging, a durability problem arose. Cartesian Robots were adopted for this improvement, and good results were obtained. The risk of breakdowns was reduced and labor productivity increased by 1.4 times.

Automation of Nail Brush Manufacturing Process
Nail brushes were mostly handmade due to the complexity of the production process. In order to reduce the aging of workers and costs, six Cartesian Robots were introduced, and the cutting, temporary attaching, and gluing processes were performed by the robots. As a result, six workers were reduced to two, and labor productivity has increased 30 times compared to before the introduction of the robots.

Reduction of Burden and Efficiency of Hazardous Work
Cartesian Robots were used to replace heavy and potentially hazardous tasks that were being handled by humans. As a result, hazards were eliminated, efficiency was improved, and labor productivity was increased 1.4 times compared to the previous system.

What Is a Rotary Table?

A Rotary Table is a rotating platform on which a device or object is mounted.

Rotary Table is used to rotate an object mounted on it to a desired orientation or angle, for positioning, or for measurement. The method of rotation can be manual or motorized. The control method can be open-loop or feedback control, and the size can be large or small, so it is important to select the right one depending on the application.

In addition, rotary tables are rarely used by themselves, as rotary motion is often accompanied by some subsequent operation, such as processing or measurement.

Rotary Table Applications

Rotary Tables are used to hold semiconductor wafers for inspection, precision measurement, and motion simulation. They are also used for precision measurement by fixing optomechanical components.

The Rotary Table itself can be mounted in a variety of orientations. It is used after considering whether it is more efficient to rotate the object to be processed or measured or the mechanical parts of the equipment.

High precision is required depending on the application: manual coarse rotation is used when a rough angle is required, while fine rotation is used when fine angle adjustment is required.

Principle of Rotary Table

Rotary Table has a cross roller bearing structure, a sliding structure, and an angular bearing structure.

1. Cross Roller Bearing System

A cross roller bearing consists of a roller race with a 90° V-groove and a cylindrical roller. The cylindrical rollers are arranged orthogonally and alternately with a contact angle of 45°. The back bearing structure in a ball bearing can be realized with a single row, enabling the bearing to receive loads from multiple directions simultaneously.

When the Rotary Table is driven, multiple cylindrical rollers roll on the roller race, which is characterized by almost no change in friction from stop to start. The cross roller bearing supports the load with linear contact and is a more rigid system than the ball guide mechanism. In addition, the rotary stage and cross roller bearing can be directly connected, which reduces the number of structural parts.

Since the rotational accuracy of the Rotary Table depends on the accuracy of the rollers, high rotational accuracy can be obtained depending on the accuracy grade of the rollers. In addition, since cross roller bearings have low frictional force and can be operated with light force, micrometer heads and other devices can be used in the fine rotation mechanism to obtain high positioning accuracy.

By connecting a stepping motor to the rotation mechanism, the angle and direction of rotation, as well as the operation procedure, can be automated.

2. Sliding Method

This is a sliding method in which one surface of the Rotary Table and one surface of the fixed side come into contact with each other. This is called dovetail sliding. The mechanism is simple, and dirt is difficult to get into the gap. Since the supporting area is large, it can withstand impact loads and large loads.

3. Angular Bearing System

Angular bearings are bearings with a contact angle to receive axial loads in one direction. When used in Rotary Table, two angular bearings are used and placed facing each other. This method provides greater rigidity for both axial and radial loads.

4. Motor-Driven

Stepping motors are often used for motorized Rotary Tables. The basic step angle is 0.36°, and the resolution is 0.004° at full step and around 0.0002° at microstep of 1/20 division.

Features of Rotary Table

1. Fine Movement Mechanism

In addition to the coarse rotation mechanism that allows 360° rotation, the Rotary Table is equipped with a fine rotation mechanism that allows fine rotation in a specific range. The fine movement rotation is performed by a worm and gear drive using a precision micrometer.

The range of fine rotation is generally ±3 to 5°. The resolution is about 5 arc-min on a vernier scale.

2. High Rigidity

The Rotary Table has very low deformation, wobble, and backlash. Axial wobble is generally less than 500 μrad.

3. Functionality

Some Rotary Tables can be used in Class 100 clean rooms. Many are also compliant with the European RoHS Directive. The coarse and fine rotation mechanisms can be locked by screws.

What Is Molding Machinery?

Molding machinery is machinery used in the molding of plastics and resins.

Specific uses include the manufacture of appliances and components. Extrusion machinery is used to produce tubes and rod products, molding machinery is used for styrene foam, and blow molding machinery is used for hollow products.

Molding machinery includes specialized machines for fluoroplastics, which are difficult to process, and vacuum molding machines, which mold under vacuum conditions, enabling high-precision molding. Molding machinery is suitable for mass production, but is now also used for small lot production.

For this reason, flexible molding machinery that can be switched in a short period of time has also been developed.

Uses of Molding Machinery

Molding machinery can mold a wide variety of materials, including plastics, metals, rubber, and ceramics. In the automotive and electrical/electronics industries, they can produce parts with complex shapes.

In the medical field, they are used in producing medical devices and prosthetics. They are also used in the construction industry to produce plastic exterior materials and roofing materials, in the food industry to produce chocolate and silicone molds, and in the textile industry to produce accessories and fabrics for spinning and weaving machines.

Principles of Molding Machinery

1. Injection Molding Machinery

Injection molding machinery consists of heating plastic raw materials and other materials, injecting them through an injection port, and placing them in a mold. In extrusion molding machinery, plastic materials are placed in a hopper, pushed out through an extrusion opening, and shaped by a mold.

2. Extrusion Molding Machinery

Molding machinery is a machine that extrudes thermoplastic materials by means of special mechanical pressure and heating. Plastic particles are fed from the machine’s feeder and melted by a heated screw.

The plastic material extruded at high pressure is then formed to fit the shape of the die, creating a shape. Finally, the formed product is cooled and separated by a cooling system.

3. Blow Molding Machinery

In blow molding machinery, plastic material is heated and placed into a hollow shaped die, which is inflated by air pressure to form the product. In molding machinery, thermoplastic resin is injected into the mold, cooled, and formed. In vacuum molding machinery, heated plastic film is applied to the mold under vacuum conditions.

Molding machinery performs molding operations in a high-temperature, high-pressure environment, so safety measures are important. In addition, factors that affect the quality of molded products include the type and quality of raw materials, mold design, and the adjustment of molding conditions. Molding machinery is suited for mass production, but today, flexible molding machines that can be switched in a short time are being developed to accommodate small-lot production.

Types of Molding Machinery

Molding machinery includes injection molding machinery, extrusion molding machinery, and blow molding machinery.

1. Injection Molding Machinery

Injection molding machinery is a machine that molds plastic material by injecting it into a mold. Injection molding machinery is characterized by its ability to mass produce at high speed. They are also highly automated, with operators simply operating the machine, which automatically performs everything from molding to ejection.

Injection molding machinery heats plastic material to melt it, and then injects the plastic through the injection port to form the mold. The plastic injected into the mold cools and hardens to form the desired shape.

Injection molding machinery is used for many products such as car panels, bumpers, computers, scissors handles, syringes, and smartphone covers. Mold design and manufacturing technology are important, as molds need to be designed according to the material and shape.

2. Extrusion Molding Machinery

Extrusion machinery is a machine that melts plastic, rubber, metal, or other materials and pressurizes and extrudes them to make tubes, sheets, profiles, pipes, and other shapes.

Plastic or resin is placed in the hopper, and the material is fed into the screw while adjusting the amount. The material is heated inside the screw to melt it and extrude it. At the end of extrusion, a mouthpiece called a die is attached to determine the shape.

3. Blow Molding Machinery

Blow molding machinery is a machine that uses air pressure to expand the material, which is then cooled and hardened as it is pushed into the die.

The temperature is raised to soften the material, which is then extruded through an extrusion screw to form a parison. The parison is cooled and molded by pressing it against the mold while blowing compressed air into it.

What Is an Air Shower?

An air shower is a box-shaped device installed at the entrance of a clean room, etc. It uses dust-free air filtered through a high purity multi-layer filter called HEPA to remove dust from people’s clothes.

Uses of Air Showers

Air showers are mainly used in semiconductor and precision equipment manufacturing facilities. In most cases, they are installed at the entrance to prevent dust from entering the clean room.

To maintain the cleanliness of the clean room, it is important to remove all the dust in the air shower. Because it can remove dust from clothes in a few tens of seconds, it is sometimes installed at the entrance of apartments for pollen allergic patients.

Principle of Air Showers

An air shower has a double door with an interlock that prevents both doors from opening at the same time. When a person enters the air shower from the outside, air is injected through the jets for a set number of seconds. The air is highly purified air that has passed through a HEPA filter.

This forces the dusty air to circulate and keeps the air shower space highly purified. Even when no one is in the room, the air is gently circulated to keep the air shower space constantly at a high level of cleanliness.

The interlocks on the double doors allow only a small amount of dust to enter when exiting, which also contributes to extending the life of the HEPA filter.

How to Choose an Air Shower

Select an air shower that meets the cleanliness requirements of the clean room, as higher dust removal performance is more expensive. Cleanliness of a clean room is classified by ISO based on the size and quantity of particles inside.

Each air shower is selected after confirming its guaranteed class. It is also possible to reduce costs by selecting a simple type of Air Shower that does not have a room. If the number of people coming in and out of the room is large or frequent, a large Air Shower that can accommodate several people at the same time may be selected.

Other Information on Air Showers

1. How to Use Air Showers

An air shower is a facility that removes dust to prevent dust from being brought into the clean room. However, if it is used improperly, it will not achieve the expected dust removal effect. First, decide on a standing position with a predetermined capacity, and mark the “stop” marker. Depending on the standing position, the air velocity hitting the body will decrease, and the dust removal effect will also be reduced.

Next, adjust the air outlet slightly downward toward the standing position. This has the effect of reducing the air blowing up and reducing re-contamination caused by the dust being blown up. During the air shower, rotate 2-3 times with your arms outstretched so that the air blows over your entire body. After rotation, the unit waits in place until the set time.

Generally, set the air shower time to about 30 seconds for one-sided blowers and about 20 seconds for two-sided blowers. 

2. Effects of Air Showers

An experiment was conducted to determine the correlation between the dust removal effect of an air shower and the time setting. In the experiment, the dust removal rate for each size was measured for 10, 20, and 30 seconds for the one-sided and two-sided types of air showers.

This experiment showed that the one-sided blowout type had a low removal rate of fine dust particles and was inferior in dust removal effectiveness. With the two-sided blowout type, the removal rate of each size of dust was almost equal, and the dust removal effect was high.

These results indicate that it is appropriate to select a double-sided blowout type for clean rooms that require high cleanliness. In places where cleanliness requirements are not high, it is more economical to use a single-sided blowing type to remove large dust and debris.

As for the dust removal time, experimental data for the two-sided blowout type shows that the dust removal effect is inferior at 10 s. Since there is no noticeable difference between 20 s and 30 s, it is generally recommended that the dust removal time be set at about 20 s. Since the dust removal effect of an air shower varies, depending on how it is used, it is necessary to ensure that it is used in an effective manner.

What Is a Positive Pressure Damper?

A positive pressure damper, also known as a differential pressure damper, relief damper, or barometric damper, is a device that regulates the internal pressure of a clean room to maintain positive pressure in the clean room.

By adjusting the differential pressure between the inside and the outside of the room, the positive pressure damper makes it possible to maintain a constant positive pressure inside a clean room.

Applications of Positive Pressure Damper

Positive pressure dampers are mainly installed in clean rooms to maintain a positive pressure inside the clean room that is one degree higher than the pressure outside the room.

They are also used in operating rooms.

Positive pressure dampers keep the room pressure higher than that outside the room, venting out only the amount of pressure that is higher than the specified value and closing the damper when outside pressure is applied to keep the room clean at all times.

Principle of Positive Pressure Damper

Positive pressure dampers are installed in ordinary clean rooms because it is necessary to keep the room at a positive pressure to prevent dust from entering from the outside.

One of the four principles for maintaining air cleanliness above a certain level is to “prevent the entry of contaminated air from the outside,” and for this purpose, the air inside the room must be kept at positive pressure (high pressure relative to the air outside the room).

On the other hand, if the pressure inside the room is too high compared to outside the room, it may cause adverse effects such as difficulty in opening and closing doors when entering and leaving the room.

Therefore, the opening door of the positive pressure damper opens and closes from time to time in response to the pressure difference with the air outside the room, making it possible to keep the air inside a clean room at a constant positive pressure.

Depending on the installation method, it is also possible to make the negative room pressure in the opposite direction.

In a clean room environment with strong pressure, the positive pressure damper may open and close frequently.

As a countermeasure, a weight can be attached to the back of the positive pressure damper’s open door to adjust the degree of opening.

Incidentally, the cleanliness of the air in a clean room is affected by the temperature, humidity, and cleanliness of the room, as well as internal heat generation, personnel in the room, local exhaust, and other factors that affect the capacity of the clean room air conditioning system.

There is also a damper with a fireproof shutter.

These dampers with fire shutters have a built-in thermal fuse that automatically closes the blades of the opening when the temperature rises above a certain level (72°C).

This allows the airflow between the damper and the point of fire to be blocked, preventing the spread of fire and the filling of toxic gases.

Variations for different applications are also available, such as X-ray protective types.

What Is a Circuit Breaker?

A circuit breaker is an electrical device capable of interrupting a circuit where an accidental current flows.

Circuit breakers for low voltage include wiring circuit breakers to detect overcurrents and ground leakage circuit breakers to detect leakage currents. Circuit breakers for high voltage are used in conjunction with protective relays because they are not equipped with accidental current detection functions.

Uses of Circuit Breakers

Wiring circuit breakers are also used as safety breakers in ordinary homes. Circuit Breaker is a device that interrupts a circuit in general, but the wiring circuit breaker installed in a home switchboard is called a safety circuit breaker.

The purpose of installing circuit breakers is to protect circuits and people from accidental currents, such as short circuits and ground faults. Since these can cause electric shock or fire, they are always installed in electrical products and switchboards.

Principle of Circuit Breaker

Wiring circuit breakers are generally of the thermodynamic electromagnetic type, utilizing the deformation of bimetal caused by overcurrents. When an overcurrent flows, the bimetal generates heat and deforms to release the latch, thereby breaking the circuit.

Thermodynamic electromagnetic wiring circuit breakers can be restored by manually returning the latch after the bimetal has cooled and returned to its original shape. RCD circuit breakers monitor the current in a circuit and interrupt it if there is a difference in traffic. If the circuit is properly insulated, the outgoing and incoming current values will be equal.

The difference between the outgoing and incoming currents is called leakage current, which is detected by the magnetic field of the zero-phase current transformer built into the RCD circuit breaker. Vacuum circuit breakers are mainly used for high-voltage circuits. Vacuumcircuit breakers are circuit breakers that turn off the arc by creating a vacuum at the opening and closing points of contact.

When a circuit with a current flowing through it is opened, a discharge phenomenon called an arc is generated. At high voltages, the arc discharge cannot be broken, and the contact point will burn up. Extinguishing the arc discharge is called quenching, and every high-voltage Circuit Breaker has a function that can quench high-voltage arc discharges.

Types of Circuit Breakers

Circuit breakers that protect against short-circuit currents of high-voltage or extra-high-voltage voltages have the function of quenching arcs, as mentioned above. Based on the arc quenching mechanism, the following types of circuit breakers are available. 

1. Aerial Circuit Breaker (ACB)

Low-voltage circuit breakers are generally used because they can be arc-quenched in the air without any problem. General low-voltage circuit breakers, such as safety breakers, are applicable to air circuit breakers . 

2. Gas Circuit Breaker (GCB)

A circuit breaker that quenches the arc by spraying an inert gas on the contacts when opening the circuit. Sulfur hexafluoride (SF6) gas is used as an inert gas, but because SF6 is a greenhouse gas, it is a circuit breaker that should be used with caution.

3. Oil Circuit Breaker (OCB)

A circuit breaker that quenches the arc using insulating oil. Since its dielectric strength is inferior to that of a vacuum, this type of circuit breaker is rarely used today. In the past, polychlorinated biphenyls (PCBs) were used as insulating oil, but the production of PCBs is now prohibited. 

4. Vacuum Circuit Breaker (VCB)

A circuit breaker that extinguishes an arc by creating a vacuum at the open/close contact point. Vacuum circuit breakers are the most common type of compact high-voltage circuit breaker. They have few actuators and are easy to maintain.

Other Information on Circuit Breakers

Difference Between Circuit Breakers and Breakers

There is no difference between circuit breakers and breakers. Breaker is an abbreviation for circuit breaker.

What Is Conveyance Equipment?

Conveyance equipment are devices that can automatically convey products between manufacturing processes instead of manually. They are used in various locations, including large factories, because they can move even heavy products safely and at low cost. The use of conveyor systems improves productivity and reduces human error.

There are various types of conveyor systems, including conveyor systems often used in manufacturing processes, automatic guided vehicles, and lifting equipment. The style of conveyor equipment is selected according to the product to be applied.

Applications of Conveyor Systems

There are various types of conveyor systems, and they are mainly used for conveyance between manufacturing processes.

Most heavy items, such as steel materials and automobiles, are manufactured using conveying equipment. In the food industry, conveyor-type transfer equipment is often used in factory production to maintain product cleanliness, moving products between processes without human intervention.

In the semiconductor industry, conveyor systems are often used to transfer semiconductors during processing while maintaining cleanliness in order to prevent contamination.

Principle of Conveyor Systems

There are various types of conveyor systems, and the principle differs depending on the type.

• Elevating Type
  The elevating type performs vertical unloading. There are simple lifts, elevators, and elevators. Since it is basically a transport device, most of them do not allow people to get in. Depending on the device, it may be necessary to check the Building Standard Law, Industrial Safety and Health Law, etc., for installation.
• Conveyor Type
  Conveyors use multiple rollers or belts. It is like a walking sidewalk. Simply place the product on the rotating rollers or belts of the conveyor and it is automatically conveyed. There are also pneumatic levitation conveyors in which the belt is supported by air to eliminate vibration.
• Unmanned Conveyor Vehicles
  This is a conveyance device in which magnetic tape or magnetic rods are installed on the floor, and a cart carrying a load is guided by the magnetism emitted from the magnetic tape, etc., so that it can proceed unmanned. It can also carry heavy objects such as molds. AGVs are also called AGVs, and are used in factories, hospitals, logistics sensors, and other facilities that operate 24 hours a day.

What Is a Centrifugal Pump?

A centrifugal pump is a type of pump that has an impeller-like impeller inside the pump casing. The casing has a volute shape and is also called a volute pump.

Liquid enters the impeller through the suction port at the center, and is propelled outward at high speed by the centrifugal action of rotation. As it passes through the volute chamber, it is gradually decelerated and converted to pressure.

There are two types of centrifugal pumps: single-stage with one impeller and multi-stage with two or more impellers. The multistage type increases pressure with each stage and is used when high pressure is required.

Uses of Centrifugal Pumps

Centrifugal pumps are often used when a high flow rate and low pressure are required. They are widely used in industrial applications such as drainage, boiler water supply, water supply and sewage, mining, and chemical industry. They are also used in agriculture, such as for irrigation, and for water supply and drainage of air conditioning units.

Centrifugal pumps are often used for relatively low viscosity solutions with a solids volume concentration of 20% or less in the liquid. Those with improved vane shapes and materials to resist wear and corrosion are used for transporting muddy water, sewage, slurries, and pulp mixtures, sand and gravel, coal, and other liquids. Furthermore, by reducing the number of blades and increasing the flow path area, they can be used to transport fish, oranges, etc. along with water.

Principle of Centrifugal Pump

Centrifugal pumps use centrifugal force to impart pressure and velocity energy to a fluid by rotating an impeller in a casing. It is then decelerated in the volute-shaped casing and the velocity energy is converted to pressure energy. This phenomenon is known as Bernoulli’s theorem.

There are two types of impellers: a radial flow form with a two-dimensional curved surface in which the fluid flows in the radial direction, and a mixed flow form with a three-dimensional curved surface that changes from axial to radial in an incremental manner. This is an important element for efficiently converting velocity energy into pressure.

The casing is installed to form a spiral-shaped chamber outside the impeller. As the cross-sectional area gradually increases in the direction of rotation, the high-speed fluid ejected from the impeller by centrifugal force is gradually decelerated and the pressure (static pressure) increases.

There is a limit to the pressure that can be generated by a single impeller. If higher pressure is required, a multi-stage pump is used. In a multi-stage pump, the fluid leaving the first impeller is sucked into the second impeller to further increase pressure. This can be repeated several times to obtain high pressure.

Pump Structure

Pump construction is closely related to flow rate and head, and is an important selection criterion when choosing a pump. Centrifugal Pumps consist of an impeller and volute casing, shaft, bearings, drive coupling, and suction and discharge couplings, shaft sealing device, and if necessary, a pressure gauge, pressure sensor, and pressure switch.

There are pumps with non-rotating fixed guide vanes arranged around the periphery of the impeller. They are called diffuser pumps or turbine pumps and are part of the centrifugal pump family. The mechanism is similar to that of centrifugal pumps, but the fluid leaving the impeller is efficiently decelerated as it passes through the guide vane and the static pressure increases, resulting in higher overall efficiency.

Other Information on Centrifugal Pumps

Centrifugal Pumps and Cavitation

Since the pump structure is designed to convert liquid to pressure, problems can occur if gases are introduced into the pump or if gases are generated inside the pump. One of these problems is cavitation.

Cavitation in pumps is a phenomenon in which the pressure of a liquid drops rapidly inside the pump, and when it reaches saturation vapor pressure, the liquid vaporizes rapidly. Cavitation in centrifugal pumps occurs when the static pressure of the fluid decreases due to the increased velocity of the liquid flowing into the impeller and the static pressure near the inlet falls below the saturation vapor pressure of the fluid.

Repeated cavitation causes damage to the impeller, resulting in cavitation erosion. Vibration and noise are also generated, and performance is reduced. This leads to premature deterioration and destruction of the equipment, not only in the centrifugal pump but also in the pipes and valves.

Cavitation can be prevented by changing operating conditions, reducing resistance on the suction side, and improving the shape and area of the impeller so that the fluid pressure does not fall below the saturated vapor pressure.

What Is an Automated Pipetting System?

Pipetting is the process of measuring and dispensing a fixed amount of a liquid (sample, medicine, etc.). It is also called an automated liquid dispensing system, automated pipetting system, or dispensing workstation. PerkinElmer, Tecan, Eppendorf, Beckman Coulter, and other companies have released such systems.

Some are preset with protocols suitable for certain ELISA kits and nucleic acid purification kits, while others can be used with a high degree of freedom by setting the volume of liquid to be collected (in some cases, the protocol itself can be programmed by the user).

Applications of Automated Pipetting Systems

Automated pipetting systems are used to process a large number of specimens, to save time and labor in simple tasks such as sample dispensing, and to avoid human error. They are used in a wide range of fields, including research, food, clinical (medical and laboratory), and drug discovery.

Specific Examples of Use

• Dispensing reagents to plates
• Transfer of samples
• Exchange of culture media
• Plate size change (replacing samples from 96-well plates to 384-well plates)
• High-speed pipetting
• Preparation of dilution series
• Plate (sample) replication, etc.

Principle of Automated Pipetting Systems

Automated pipetting systems are composed of three major components: a liquid handling section that transfers a fixed amount of reagent or sample to microplate wells, a transport section that moves nozzle heads, pipettors, and plates, and a computer that controls the movement of these components.

In automated pipetting systems, the liquid handling section is particularly important for product performance and, like the manual pipettor, it is marked with “accuracy” and “reproducibility” values.

The dispensing operation is based on a computer-programmed protocol, in which a liquid collection head weighs a predetermined amount of reagent into a predetermined plate (position) or tube.

The grade of the instrument varies depending on the number of pipettors available (for pipettor type instruments), the number of reagents that can be recognized simultaneously, the presence or absence of a heating mechanism, and the presence or absence of expandability. Some products have optical sensors to detect various lab ware, reagents, and chips, and monitoring systems to prevent malfunctions.

What Is an Industrial Camera?

An industrial camera is used in factories or for security purposes. There are two main types: monitoring cameras and machine vision cameras. Monitoring cameras, often used for surveillance, are connected to a monitor for visual observation. This category includes cameras used for digital microscopes. Machine vision cameras, integrated into manufacturing processes, process image data for automatic inspections.

Uses of Industrial Cameras

Monitoring industrial cameras are used in security cameras, surveillance cameras, in-vehicle recorders, and digital microscopes. These cameras are also commonly installed in ATMs and cash registers. On the other hand, machine vision industrial cameras are primarily used in manufacturing processes for inspection systems, where they automate the analysis of captured images.

These applications include defect and foreign matter inspection, criteria determination for liquid container filling, barcode reading, character recognition, and other uses in the automotive, medical, electrical, electronic, logistics, and printing fields.

Principle of Industrial Cameras

Industrial cameras consist of a lens and a body, similar to digital cameras. Light entering through the lens is converted into digital data by an image sensor in the body. These sensors can detect visible light, infrared, ultraviolet, and X-rays. Their performance varies based on size, pixel count, and scanning method.

How to Select an Industrial Camera

When selecting an industrial camera, consider its specific applications and minimum performance requirements. Key considerations include:

1. Need to Capture Entire Surface

There are two types of industrial cameras: area cameras and line sensor cameras. Line sensor cameras, with a single row of elements, can capture an entire product by moving it, ideal for cylindrical or flat objects. For line monitoring and inspection, line sensor cameras can be sufficient.

2. Image Requirements

The choice of camera depends on the needed color information, resolution, and acquisition speed. Monochrome cameras suffice for shape detection. Higher resolution increases cost and data volume, which should match the inspection throughput.

3. Interface

Consider how images and videos will be captured. Common interfaces include USB, CameraLink, and Gigabit Ethernet, each with different transfer rates and cable length limitations.

Other Information on Industrial Cameras

Differences in Image Sensor Scanning Methods

There are two scanning methods: interlaced and progressive. Interlaced, which alternates between even and odd lines, suits monitoring purposes like surveillance cameras for smooth motion depiction. Progressive scanning, displaying all lines simultaneously, is better for capturing moments and is used in machine vision in manufacturing.