月: 2023年11月

What Is a Thin-Film Evaporator?

A thin-film evaporator is a device for separating and refining mixtures by forming a thin film to concentrate and evaporate low-boiling-point components (solvents).

Low-boiling point solvents can be evaporated in a short time. Since the heating time can be shortened, it is especially effective for separation and purification of heat-sensitive compounds. It can also be used to process high-boiling point liquids by creating a high vacuum.

Applications of Thin-Film Evaporators

Thin-film evaporators are used to concentrate, dry, and powder solutes (samples) by removing solvents, and to recover reusable solvents and water from spent solvents, waste liquids, and process liquids.

1. Chemistry

In the chemical industry, it is used to separate and purify organic compounds in general, such as amines, esters and other aromatic substances, latex, and monomers. It is also used to recover acetic acid, and to purify monoglycerides, fatty acid amides, various fatty acids and fatty acid derivatives, methacrylic acid derivatives, acetylene derivatives, and compounds with high boiling points.

2. Pharmaceuticals

Major applications in the pharmaceutical industry include the distillation and processing of vitamins, fats and oils such as DHA, EPA, and squalene, as well as the concentration and purification of common organic compounds.

3. Food

Thin-film evaporators are also commonly used in the food industry. Specific applications include the concentration and purification of proteins and sugars, as well as the concentration treatment of various juices, milk, etc.

4. Machinery & Electronics

Thin-film evaporators are also used in the refining of vacuum pump oil, refrigerator oil, and transformer oil, as well as in the vacuum heating treatment of sealing and molding materials used in electronic and semiconductor components.

5. Waste Liquid Treatment

Thin-film evaporators are used for concentration, water recovery, solvent recovery, and volume reduction of process liquids and waste liquids in general industrial production. They are used in various fields such as cutting oil waste in the metal industry, metal surface treatment industry, chemical industry, textile industry, leather industry, and dye industry.

Principles of Thin Film Evaporators

Thin-film evaporators concentrate and dry solutes based on the principle of evaporating solvents by forming a thin film in an evaporation tube equipped with a heating mechanism. Wipers and other devices are built into the evaporation tube to efficiently form a uniform thin film. Since the inside of the evaporation tube is usually designed to be depressurized, the solvent can be removed at low temperatures and in a short time by lowering the boiling point of the solvent through depressurization.

The solute precipitated as a solid is scraped off with a wiper or similar device and sent to a collection vessel. The evaporated solvent is passed through a tube as a gas, trapped in a cooling tube, and re-cooled to be recovered as a liquid. Usually, the evaporation tubes and liquid and gas channels of lab-scale equipment are made of transparent materials such as borosilicate glass, which are resistant to corrosion and chemicals and allow for internal observation.

Types of Thin-Film Evaporation Devices

Thin-film evaporators come in a variety of sizes, ranging from laboratory-size to large, industrial-use ones. Laboratory-size ones are usually made of glass, while industrial-scale ones are made of stainless steel or other materials.

In a normal thin-film evaporator, the evaporation tube is vertical so that the distillate flows down, enabling efficient separation and purification. For this reason, most equipment feeds the mixture to be separated from the top, but there are also rising thin-film evaporators that introduce the mixture from the bottom and heat it to rise. Other shapes include horizontal thin-film evaporators used for industrial applications.

4. Centrifugal Thin-Film Evaporators

Centrifugal thin-film evaporators are a type of thin-film evaporators for industrial use. Centrifugal thin-film evaporators are equipped with rotating blades and use centrifugal force to thin-film the processing liquid on the inner surface of the body. Solvent is evaporated by heat transfer from the jacket and vacuum decompression. Generally, these are large devices for industrial use and are available in a variety of types, including horizontal, vertical, scraping, and sanitary types. They have high separation efficiency and are especially suitable for distillation of high-boiling point solvents.

5. Short-Path Evaporators

Short-path evaporators are similar to thin-film evaporators. Short-path evaporators are capable of creating a higher vacuum in glassware than thin-film evaporators. The short-path evaporator is more suitable when operation in a high vacuum is required, such as for distillation and separation of high-boiling-point components. It is also more suitable for thermally sensitive separations because it can lower the operating temperature and shorten the time required.

What Are Ultraviolet Protective Glasses?

Ultraviolet protective glasses are glasses that protect the eyes from ultraviolet (UV) radiation.

Ultraviolet rays, part of the electromagnetic waves emitted by the sun, are in the ultraviolet region and have wavelengths shorter than visible light. Prolonged exposure to UV radiation can cause a variety of health problems to the skin and eyes, so appropriate UV protection should be taken. UV protective eyewear can be used to prevent UV exposure to the eyes.

Exposure to sunlight and glare can cause eye fatigue and stress. UV protective eyewear can be used to reduce glare and ensure comfortable vision.

Uses for UV Protective Glasses

UV protective eyewear is used for a variety of purposes. The following are just a few examples of uses for UV protective glasses:

1. Construction Industry

Because construction workers typically work outdoors and are exposed to increased UV radiation from the sun, it is recommended that they wear UV protective eyewear. This protects workers’ eyes and prevents eye health problems.

2. Agriculture

Agricultural workers require working outdoors for extended periods of time. Due to prolonged exposure to sunlight, UV protective eyewear may be required during agricultural work. They also help protect the eyes from pesticides and chemicals.

3. Medical Care

Dentists often use UV curing materials in dental procedures. These materials harden when exposed to ultraviolet light and serve to reinforce the teeth. When working with UV-curing materials, dentists need to protect their own eyes from UV light when treating patients’ teeth.

Dermatologists may also perform phototherapy when diagnosing and treating skin diseases. In these cases, UV irradiation is necessary, and medical personnel use UV protective eyewear to protect their eyes while treating patients.

4. Food Industry

In the food manufacturing industry, UV germicidal lamps are used to sterilize surfaces such as package containers. This prevents microbial growth and contamination and maintains product quality. It is recommended that workers working around this equipment wear UV protective eyewear to protect their eyes.

Principles of UV Protective eyewear

The lenses of UV protective eyewear have the ability to filter out specific UV wavelengths. This is achieved by applying a special coating to the lens or by using a special material; UV filtering prevents UV rays from passing through the glasses, thus preventing direct exposure of the eyes to UV rays.

UV protective eyewear is designed to block UV rays while allowing visible light to pass through. They protect the eyes from UV rays without affecting everyday vision or visual quality. This enables the function of providing vision as a pair of spectacles.

Other UV glasses that absorb UV rays are also available. Absorbing ultraviolet protective eyewear works by drawing ultraviolet rays into the lens and absorbing them, thereby protecting the eyes.

How to Select UV-Protective Glasses

When choosing UV protective eyewear, several important factors should be considered. The following are key factors in selecting UV protective eyewear:

1. Size

The frame size of the glasses is an important factor in selecting the right product for the shape of the face. If the frames do not fit, comfort and protection may be compromised. It is important to select the appropriate size by checking the width of the frames and it is recommended to try on the frames to check the fit.

2. Ultraviolet Ray Cutoff Rate

One of the most important features of UV protective eyewear is the UV cut-off rate. The UV cutoff rate is indicated on the label or description of the glasses, so choose a product with a high cutoff rate (usually 99% or higher).

3. Material

Frame material is an indicator that affects durability and comfort. Common materials include plastic and titanium. Choosing a lightweight, durable material will ensure comfort during prolonged use.

Lens material is also important in protecting the eyes. Polycarbonate and other materials that are lightweight and strong are generally used.

What Is a Transformer Bushing?

A transformer bushing is a component that provides electricity while supporting electric wires using transformer insulation.

Electric wires need to be supported because they are affected by gravity, but if they are supported by metal parts, they will cause ground faults and short circuits. Therefore, they must be robustly supported by insulators, resin, or other insulating materials. Transformer bushings play a crucial role in supporting and insulating the wires, as well as transmitting electrical energy.

It has high insulation performance and can insulate both the high-voltage side and the low-voltage side in a transformer. Generally, bushings with larger isolation distances are used on the high-voltage side.

With proper maintenance and inspection, transformer bushings are long-lasting and highly reliable components. They contribute to the stability and supply reliability of the power infrastructure.

Applications of Transformer Bushings

Transformer bushings are used in transformers and peripheral equipment. Peripheral equipment includes bus ducts and anti-collision plates. Applications include power distribution plants and substations.

1. Electric power distribution plants

Power distribution plants are facilities that branch power lines and distribute power. They often have transformers, which convert high-voltage lines to low-voltage lines for easier handling. Transformer bushings are used at the junction points of high-voltage transmission lines and low-voltage distribution lines to provide isolation in the transmission and distribution of power.

2. Receiving substations

Transformer substations are facilities that receive high-voltage power from transmission lines, convert it to low-voltage power, and supply it to general consumers. Transformer bushings ensure the insulation performance of transformers and prevent ground faults and short circuits in transformers. This improves the safety and reliability of the receiving substation.

Principles of Transformer Bushing

Transformer bushings are components that efficiently and safely transmit electric power while insulating electric wires. Its structure is based on a combination of insulators and conductors.

The most important function of a transformer bushing is to completely insulate the charging section. This prevents electrical ground faults and short circuits. Insulation is provided by insulating materials, which typically include ceramic, glass, and polymers (plastics). Transformer bushings have conductors inside to transmit electrical energy from the high-voltage side to the low-voltage side.

These conductors are made of highly conductive materials such as copper or aluminum to ensure reliable current transmission. Transformer bushings are attached to the transformer itself or to equipment at the receiving substation to establish a power transmission path. The high voltage side is often connected to transmission lines or transformers, while the low voltage side is connected to the power distribution system.

How to Select a Transformer Bushing

When selecting a transformer bushing, several important factors should be considered. The following are transformer bushing selection factors:

1. Operating Voltage

The voltage level of the transformer bushing should be selected to match the voltage level of the wires to which it will be connected. It is important to comply with the voltage range designed for safe operation within the specification voltage range. Bushings for high voltage and special high voltage are sold, with special high voltage bushings available for 66kV, 154kV, 275lV, and other types.

2. Insulator Material

The insulating material of the bushing is important to insulate the charging section. Common insulating materials include ceramic and polymer (plastic). Ceramic insulators are robust and less susceptible to contamination, while polymer insulators are easier to mass produce and process.

3. Allowable Current

The allowable current of a bushing indicates its performance with respect to current loading. It is necessary to select a bushing that matches the design current of the transformer and has the allowable current capacity to handle the load.

4. Dimensions

The dimensions of the bushing must match the design of the transformer and peripheral equipment. It is important to select bushing dimensions for the high voltage side and the low voltage side and plan to fit into the installation space.

5. Contamination Resistance

When used outdoors, the bushing’s resistance to contaminants is important. Especially in salt-affected areas, it is necessary to minimize the adhesion of contaminants by surface treatment of the bushing. Transformer bushings for protection against salt damage are also available.

What Is UV Curable Adhesive?

UV curable adhesives are adhesives that cure by irradiating with ultraviolet (UV) light. They cure through a chemical reaction initiated by the application of activation energy using ultraviolet light, and are characterized by their ability to bond quickly.

They can also bond a wide range of materials, including electronic components, metals, glass, and plastics. However, UV irradiation lamps are required and cannot be used on parts that cannot be irradiated.

Uses of UV Curable Adhesives

UV curable adhesives can bond a wide variety of materials, including glass, plastics, metals, and ceramics, and can shorten working hours through high-speed bonding. They are used in many industrial fields, including automobiles, electronic components, assembly of smartphones, digital cameras, and liquid crystal displays, and optical components. Approved ones are also used in medical applications, and the adhesives are used in dental fillers and cements, as well as in the assembly and repair of medical equipment.

Principles of UV Curable Adhesives

1. Bourdon Tube Gauge

UV curable adhesives are activated by irradiation of ultraviolet light as an energy source, causing a photopolymerization reaction to proceed. The main components are a photoinitiator, a polymer or monomer as the main ingredient, and additives (stabilizers, etc.). The initiation and progression of the polymerization reaction are as follows:

1. The photoinitiator absorbs UV light and generates the active species: radicals, cations, or anions.

2. The active species generated by the initiator cause the polymerization reaction of the adhesive’s main component to proceed. Monomers are converted into polymers with larger molecular weights, and components that were originally polymers are converted into larger polymers.

3. The melting point rises as the molecular weight increases due to the polymer formation, and the adhesive goes from a liquid to a gel-like state, then quickly becomes solid and cures.

Characteristics of UV Curable Adhesives

One of the characteristics of UV curable adhesives is that the curing reaction proceeds quickly, from a few seconds to a few minutes, and the working time can be shortened compared to other adhesives. However, it should be noted that UV irradiation lamps are always required and that they cannot be used on parts that cannot be irradiated with UV light. The chemical bonds created by UV irradiation are strong bonds such as covalent bonds, and they also have excellent chemical resistance, heat resistance, and moisture resistance.

In the past, mercury lamps were used for UV irradiation, but UV LED products with high output and long life are now commercially available, and are now regarded as an environmentally friendly method.

Types of UV Curable Adhesives

The types of UV curable adhesives are mainly divided into acrylic resin-based adhesives using a radical polymerization reaction and epoxy resin-based adhesives using a cationic polymerization reaction.

In acrylic resin-based adhesives, radicals are generated from the polymerization initiator by UV irradiation. This radical reacts with the acrylic resin, causing a radical polymerization reaction to proceed, resulting in the formation of a polymer and curing. In epoxy resin-based adhesives, UV irradiation generates acid from the polymerization initiator, which reacts with the acrylic resin. As a result, a cationic polymerization reaction proceeds, resulting in polymerization and curing.

In general, acrylic resins are less expensive and have the advantage of faster curing speed. On the other hand, cationic polymerization type resins are not inhibited by oxygen and are less prone to shrinkage during curing. Therefore, epoxy resin-based adhesives may be more suitable for applications such as lenses, where positional accuracy is required. Curability, hardness, and viscosity also vary depending on the product, and some can be adjusted. Appropriate selection should be made according to the application.

What Is a Polymer Adhesive?

Polymer adhesives are adhesives that use polymers, which are macromolecules.

They are capable of bonding a wide variety of materials, including metals, plastics, wood, glass, and ceramics. Most polymer adhesives are manufactured from man-made synthetic materials and can be given specific properties such as flexibility, heat resistance, chemical resistance, and electrical conductivity, depending on the application.

Applications of Polymer Adhesives

Polymer adhesives can be used on a wide variety of materials including metals, plastics, ceramics, glass, leather, wood, rubber, and concrete.

They are used in a wide range of industries, including industrial, construction, automotive, marine, and aerospace. Approved products can also be used in the medical field. In addition, adhesives with high electrical insulation properties are suitable for electronic components and are used in electronics, packaging, and other fields.

Principle of Polymer Adhesives

Polymer adhesives are liquid substances that adhere to the surface of an object in a liquid state and later cure to produce an effect. Curing is caused by polymerization, chemical reaction with curing agents, and evaporation of solvents.

Their action consists of both adhesive force, to stick to the base material, and cohesive force, to maintain the structure of the adhesive itself. Adhesive force is the force that sticks different molecules together, while cohesive force is the force that keeps the same type of molecules together.

The adhesive force of polymer adhesives depends on one of the following mechanisms: physical adhesion, chemical adhesion, or dispersion adhesion.

1. Physical Adhesion

Physical adhesion is a mechanism whereby the adhesive adheres mechanically by flowing into holes or adhering to protrusions on the surface of the substrate. It is a particularly effective adhesion method when there are small holes on the surface of the base material.

2. Chemical Bonding

Chemical adhesion is adhesion by chemical bonding. The strongest bonds are ionic and covalent bonds, and the next strongest are hydrogen bonds. Ionic bonding is a bond between a positively charged cation and a negatively charged anion due to electrostatic attraction, while covalent bonding is a bond formed by the sharing of some valence electrons between atoms. Hydrogen bonding is an interaction in which a hydrogen atom covalently bonded to an atom with high electronegativity forms an interaction with a nearby solitary electron pair such as nitrogen, oxygen, sulfur, fluorine, or π-electron framework.

3. Dispersion Bonding

Dispersion adhesion is an adhesive bonding by van der Waals forces (force of electrostatic attraction between two substances due to polarized positively and negatively charged areas within the substance).

Types of Polymer Adhesives

Polymer adhesives include emulsion-type adhesives in the form of a suspended water solution, solution-type adhesives in which the polymer is dissolved in a solvent, reaction-type adhesives in which curing begins when a chemical reaction occurs when exposed to light (ultraviolet light), heat, or pressure, and hot-melt adhesives, which are thermoplastic adhesives.

1. Emulsions

Emulsion-type adhesives are adhesives in which the polymer is emulsified without dissolving and is in the form of a suspension/suspended water solution. Typical substances include vinyl acetate resin emulsions and acrylic resin emulsions. Vinyl acetate emulsions are widely used adhesives for woodworking, while acrylic emulsions are more adhesive and water-resistant adhesives. Synthetic rubber emulsions are used in flooring adhesives. In particular, adhesives that are mainly made of natural or synthetic rubber are called latex adhesives.

2. Solution Type

Solution-type adhesives are made by dissolving polymers in organic solvents. There are several types such as vinyl acetate resin, chloroprene rubber, and natural rubber. Vinyl acetate resin is inexpensive, and chloroprene rubber is a typical rubber-based adhesive used for bonding metals, plastics, and wood. In general, rubber-based adhesives are suitable for bonding soft materials such as leather, rubber, and cloth.

3. Reactive Type

Reactive adhesives are adhesives that cure through a chemical reaction caused by some form of energy such as light (ultraviolet rays, etc.), heat, or pressure. Some are cured using ovens, curing furnaces, UV lamps, etc., while others cure spontaneously at room temperature. Many products become thermosetting polymers after curing.

Since some types of reactions use two or more chemical species, there are not only one-component type products, but also many two-component type products that are mixed just before use. Specific polymer types used include phenolic resins, amino resins, epoxy resins, polyurethane, and acrylic resin systems.

What Is an Air Gauge?

An Air Gauge is an instrument used to measure the pressure of high-pressure air when handling it.

It may refer to a pressure gauge for high-pressure air pipes or tanks, or it may refer to an instrument that measures the pressure of air in tires. Both have similar construction and principles.

It is important to routinely check the pressure of high-pressure air pipes and tanks to ensure their proper operation. Pneumatic tires are filled with high-pressure air, and proper air pressure must be maintained for the tires to perform as they should.

Therefore, air gauge has an important role to play in measuring air pressure.

Uses of Air Gauges

Air gauges are used to check air pressure. Air gauges for high-pressure air lines and tanks are used to verify that the actual pressure matches the required pressure for the equipment.

Air gauges for tires are useful for checking the air pressure in inflated tires for automobiles, motorcycles, or bicycles.

Principle of Air Gauges

1. Bourdon Tube Gauge

The most commonly used analog air gauge is the Bourdon Tube Gauge. This gauge uses a bent metal tube that is blocked at one end. When pressure is applied, the tube’s bend stretches. The needle rotates in conjunction with the deformation of the metal tube to indicate the pressure. Although highly accurate, these gauges are mechanical and precise, and their vulnerability to shock is a drawback.

2. Spring-Type Gauge

Spring-Type Gauges are often used in the same way as Bourdon Tube Gauges. The pressure is antagonistic to the spring, and the pressure is indicated by the indicator needle in conjunction with the contraction of the spring. It is characterized by its simple structure and relatively high shock resistance. These gauges are used in portable air gauges for tires and in pressure gauges for daily inspections of high-pressure piping.

3. Diaphragm-Type Gauge

A diaphragm is a membrane. A diaphragm is used to measure pressure by detecting the pressure that causes the diaphragm to cave in. There are two detection methods: One is to connect the diaphragm to a Bourdon Tube Gauge and measure mechanically, and the other is to read the deformation of the diaphragm electrically.

Types of Air Gauges

1. Pressure Gauges for high pressure air piping and tanks

Pressure gauges for high-pressure air piping and tanks are sometimes called air gauges. They are used to check if the pressure is within the normal range during daily inspections, and the most common type is the durable spring type.

2. Air Gauge for tires

When we call them air gauges, we generally refer to those for tires. There are analog and digital display methods, and mechanical and electrical methods for converting detected pressure to display. In the case of analog types, most gauges are either Bourdon-Tube or Spring-Type Gauges.

They range from small, simple portable gauges to large, precise gauges that are regularly used at gas stations and maintenance shops. Since Bourdon tube gauges are sensitive to shocks, the entire gauge is usually covered with rubber.

Some gauges are integrated with air injection valves and operating devices. An example of this type of gauge is one that is inserted into the air valve of a tire and is inflated when the grip is held short and inflated when held long. This type is connected to an air tank.

Other Information on Air Gauges

Air Pressure Units

The SI unit of pressure is Pa. In general, air pressure gauges are also displayed in Pa. For safety reasons, it is especially important for gauges used for high-pressure air pipes and tanks to use the same units, and SI units are strictly enforced. On the other hand, most gauges for tires are calibrated in units of 100 kPa.

This is because the air pressure of passenger car tires is around 200 kPa, and this scale is easy to read. Another reason is that in Japan, kgf/cm2 has been used for tire pressure.

Since 100 kPa is approximately 1 kgf/cm2, by using the scale in units of 100 kPa, people familiar with either unit can handle the gauges without much discomfort. Gauges with kgf/cm2 and bar indications are still sold today.

Foreign-made air injectors and other equipment may be denoted in units common in foreign countries. In the UK, they may be denoted in psi. As a guide, 30 psi is equivalent to about 200 kPa.

What Is a MEMS Gyroscope?

A MEMS gyroscope is a device created using MEMS technology.

MEMS stands for ‘Micro Electro Mechanical Systems.’ A Gyroscope, also called a gyroscope sensor or gyro, is a sensor that detects the motion of an object and measures the change in angle per unit of time.

Applications of MEMS Gyroscopes

MEMS gyroscopes are electronic devices used in ship attitude heading control, construction equipment control, and automotive navigation and body stability systems. In these applications, the attitude and azimuth angles of objects are detected.

Devices familiar to us include smartphones, digital cameras, and game consoles. There are many applications that move according to the movements of smartphones, and MEMS detects these movements.

MEMS gyroscopes are used in the motion detection of game console controllers and in the image stabilization function of digital cameras. Drones, which have become popular in recent years, are another typical device which relies on MEMS Gyroscopes for its function.

In reality, however, attitude is controlled by an inertial measurement unit (IMU), which also includes a gyro sensor.

MEMS Gyroscope Principle

Most MEMS gyroscopes use the Coriolis force. The Coriolis force is a force acting orthogonally to the direction of vibration and the axis of rotation of a vibrating object when the object is rotated.

For example, if an object of mass m moving at each velocity ω tries to move at velocity V, a Coriolis force of magnitude 2mVω acts in the direction orthogonal to the axis of rotation and velocity. m is a very small machine in MEMS, so the mass m is also very small, but the velocity V can be a large value because the resonance frequency is high. Velocity V can be large because of the high resonance frequency.

In a vibrating MEMS gyroscope, the MEMS element is subjected to vibration and the Coriolis force is detected when ω is applied externally as a rotational motion. For example, a capacitive MEMS gyroscope captures the change in capacitance that occurs when the Coriolis force acts on the electrodes of a comb structure.

While mechanical gyroscopes that are not MEMS gyroscopes use the “Koma principle,” MEMS gyroscopes are predominantly vibration-based.

Types of MEMS Gyroscopes

MEMS gyroscopes are chosen based on the application and conditions of use, but there are four types of gyroscopes in terms of structure. These can be classified into four types according to the structure of what receives the Coriolis force: beams, sounders, plates, and rings.

Other Information on MEMS Gyroscopes

Differences from IMUs

MEMS gyroscopes are used in our everyday devices such as smartphones, but recent technology uses an inertial measurement unit called an IMU. In addition to drones, which are listed in the “uses” section, IMUs are also being used in areas such as automated vehicle driving, agriculture, and remote control of construction equipment.

In addition to gyros, IMUs incorporate acceleration and temperature sensors. Our three-dimensional world can be generally described by translational and rotational motions of three orthogonal axes, represented by x, y, and z, respectively. A gyroscope is a sensor unit that detects rotational motion of these three axes.

An accelerometer is a sensor unit that detects the translational motion of the three axes. The IMU integrates these sensor units and performs various corrections among the sensors. The IMU provides more stable and accurate control than when single sensor units are used independently.

What Is a Scintillation Detector?

A scintillation detector is a device that uses a photodetector to visualize the scintillation light occurring when charged particles, known as scintillators, pass through it.

It is a radiation measuring instrument used to visualize radiation, which is invisible to the naked eye.
There are different types of scintillators used in scintillation detectors: inorganic, organic, solid, and liquid.

In addition to scintillation detectors, there are other instruments used to measure radiation, such as GM counter tube survey meters and ionization chambers.

Uses of Scintillation Detectors

Scintillation detectors are devices used in a wide range of fields:

1. Survey of mineral resources including petroleum

Radioactive isotope-bearing layers often exist around oil reservoirs, helping to determine the location of oil drilling.

2. Airport baggage screening

In the security field, this is an airport baggage screening machine. The principle is the same as X-ray imaging. When baggage is irradiated with radiation, the radiation is weaker in the area where the baggage is located and stronger in the area where there is no baggage.

3. PET

PET (Positron Emission Tomography) used in hospitals is a device used to detect cancer cells. Since cancer cells consume more glucose than normal cells, cancer cells can be detected by administering glucose mixed with a small amount of radiation to the patient.

4. Other

Scintillation detectors are also used in food inspection equipment, high-energy physics fields such as nuclear fusion reactors, non-destructive inspection equipment for electronic components and cultural heritage, and landmine detection equipment.

Principle of Scintillation Detectors

A scintillation detector is a device consisting of two main components: a scintillator and a photodetector. The scintillator absorbs incident X-rays and emits visible and ultraviolet light in proportion to the X-ray energy.

The photodetector, also called a photomultiplier tube, is the site where electrons are converted to light and doubled. It consists of a photocathode, which converts light generated by the scintillator into electrons, and an electron multiplier, which amplifies the converted electrons.

The photocathode is mainly composed of alkali metals and receives scintillation light through a glass window. The electrons converted by the photocathode are amplified by the electric field created in the electron multiplier, to which a high voltage is applied. These amplified electrons become an electrical signal that indicates the presence of X-rays.

Types of Scintillation Detectors

Scintillation detectors are classified according to the type of scintillator, which is selected according to the type of radiation to be detected and the purpose of use.

1. Inorganic Scintillators

Inorganic scintillation detectors are used to detect gamma rays, alpha rays, and neutrons. Inorganic crystals such as Nal (Tl), cesium iodide crystals (Csl), gadolinium oxysulfide (GOS), and gadolinium silicate crystals (GSO) are the most common types. Inorganic scintillators are characterized by high luminescence and high energy resolution, and are used in X-ray imaging equipment, food inspection equipment, luggage inspection equipment, medical PET, vehicle body inspection equipment, X-ray satellites, etc.

2. Organic Scintillators

Organic scintillators, which use organic crystals, are characterized by better response than inorganic scintillators. Typical materials include anthracene and stilbene.

3. Organic Liquid Scintillators

Organic Liquid Scintillators are characterized by their resistance to damage even when exposed to strong radiation. Organic Scintillators such as PPO (diphenyloxazole) are dissolved in organic solvents such as naphthalene, toluene, or xylene.

4. Plastic Scintillators

Plastic scintillators are made by dissolving several types of organic luminescent substances in plastic. They are suitable for detection of alpha and beta rays.

5. Gas Scintillators

High purity xenon, helium, etc., are used for gas scintillators.

What Is an Industrial Ink?

Industrial Ink is a type of ink used in industrial inkjet printers and printing machines.

Since printing on a wide range of materials is required for industrial use, a variety of pigments and dyes are included.

Applications of Industrial Inks
Industrial products may require various types of printing, such as lot numbers, quality markings, and inspection stamps. Stamp marking inks are used for printing on various materials, including metal, plastic, paper, cardboard, ceramics, glass, wood, cloth, and leather.

Industrial inkjet printers are also used in diverse applications such as commercial printing, textiles, and building materials. Major applications include sign graphics; textile products such as digital textile printing, DTG, and banner flags; 3D modeling such as models, parts, and molds using UV curable resins and plaster; and name tag, label, and metal can printing. Diverse types of ink for inkjet printers are available to suit these product materials.

Principles of Industrial Inks

1. Inkjet Printing

In industrial production, industrial inkjet printers are used to print many products. Inkjet printing with inkjet printers is a printing method in which images are drawn by applying liquid ink drop by drop.

Ink for inkjet printers is composed of colorants such as dyes and pigments dissolved in a solvent. Pigments are large particles that remain on the surface of the object without penetrating it, while dyes are colorants that soak into and penetrate materials like paper. Pigments print clearly and vividly, while dyes can be mixed to produce delicate colors and gradations. Solvents include volatile organic solvents such as MEK (methyl ethyl ketone), ethanol, acetone, water, and other organic solvents.

Other agents found in ink include penetrating agents (which lower the surface tension between paper and ink to facilitate ink fixation on paper), anti-drying agents (which prevent ink from drying out and clogging the print head), pH adjusters, preservatives, and fungicides. These auxiliaries are necessary to maintain ink quality and print quality.

2. Ink for Stamp Marking

Ink used for printing lot numbers and other information is called a stamp marking ink. It is used for stamp marking and is used in the same way as general stamp inks. There are oil-based pigment-based, oil-based dye-based, water-based pigment-based, and water-based dye-based inks, and they are used according to the material to be stamped. Inks used on non-absorbent material surfaces are solvent-based dyes. There are also special inks. In addition to the ink itself, some inks are sold as ink pads impregnated with ink.

Types of Industrial Inks

Industrial Inks are available in a variety of basic colors, such as black, white, red, blue, yellow, and green. In addition to classification by colorants such as dyes and pigments, there are also different types of inks depending on the solvent used, such as water-based inkjet inks, solvent-based inkjet inks, and UV-curable inkjet inks. Since the materials suitable for printing differ depending on these different solvents, care must be taken when making a choice. In addition, some solvent-based inkjet inks are quick-drying and others are not, depending on how easily the solvent volatilizes.

1. Water-based Ink

Water-based ink uses purified water as the solvent. Unlike organic solvents, there is no adverse effect on the human body and no concern about environmental pollution, but compared to methyl ethyl ketone and ethanol, it has a longer drying time and is more difficult to dry. Therefore, printing is limited to permeable materials such as paper. This ink is suitable for continuous forms, commercial printing, cardboard, flexible packaging, labels, etc.

While water-based ink is the most commonly used ink in inkjet printers for office automation, water-based ink is less commonly used in industrial inkjet printers. In addition to water and colorants, additives such as moisturizers, penetrating agents, pH adjusters, and preservatives are included.

2. Solvent-based Inks

MEK (methyl ethyl ketone) is mainly used for fast-drying solvent-based inks. Inks using methyl ethyl ketone dry and solidify quickly, so they can only be used in continuous inkjet printers that constantly circulate ink. Because it dries and solidifies quickly after printing, it can be used to print on non-permeable materials. In addition, inks containing methyl ethyl ketone are designated as Class 4 Hazardous Substance, Petroleums No. 1 (non-water soluble liquid).

Ethanol and acetone are used for solvent-based inks that do not contain methyl ethyl ketone. Ethanol is a solvent that takes longer to dry than methyl ethyl ketone, but is used in food packaging and other applications because of its volatility and lack of risk of chemical contamination. Acetone, although flammable, dries more quickly than methyl ethyl ketone and is used for printing on soft packaging materials such as plastic wrap. Demand for such solvent-based inks that do not use methyl ethyl ketone is increasing due to safety measures and cost reductions in complying with regulations.

What Is a Hall Effect Current Sensor?

A Hall effect current sensor is a device that measures current using the Hall effect in a magnetoelectric conversion element, known as the Hall element. These sensors are capable of non-contact detection and continuous measurement of AC and DC currents, with some models capable of detecting currents up to 4000A.

Applications of Hall Effect Current Sensors

Hall effect current sensors are utilized in various applications:

• As AC/DC sensors in manufacturing processes.
• In current probes for broadband waveform observation in DC and AC.
• In automotive applications for battery output monitoring in large vehicles.
• In industrial equipment for power consumption monitoring and maintenance.
• In energy systems such as solar and wind power generation, and fuel cell systems.

Principle of Hall Effect Current Sensor

Hall effect current sensors operate by converting a magnetic field around a current into voltage (Hall voltage) using a semiconductor Hall element. The sensor measures this voltage to determine the current value. The Hall effect occurs when a magnetic field perpendicular to current flow induces an electromotive force in an orthogonal direction.

Components of Hall Effect Current Sensors

• Hall Element: A semiconductor device used in the sensor, typically made of materials like InSb, InAs, and GaAs for high sensitivity.
• Sensor Mechanism: Consists of a magnetic core with a Hall element and an amplification circuit to detect magnetic flux and generate Hall voltage.

The sensor measures current without contact, providing excellent insulation properties and the ability to measure various types of currents.

Types of Hall Effect Current Sensors

These sensors vary in terms of current detection range, form factors, and mechanisms. They are available in through-hole and clamp types and can use Hall ICs or feedback current for magnetic field cancellation. The choice of sensor depends on the specific application requirements.