月: 2023年12月

What Is a Swivel Carabiner?

A swivel carabiner is a device used to connect a lifeline and rope. Its eye section rotates, allowing smooth rotation of the swing without twisting the rope. These devices are primarily made of materials such as aluminum alloy and lightweight reinforced aluminum, making them ideal for activities like rock climbing and mountaineering.

Swivel carabiners feature a mechanism where a portion is opened and closed using a metal ring. They are used not only in mountaineering gear but also in various outdoor activities such as camping, as well as in everyday life. Available in various sizes, some models come equipped with anti-fall screw locks.

Swivel carabiners are not only utilized as practical items, such as keychain attachments, backpack zipper pulls, and strap connectors but are also incorporated into fashion trends.

What Is a Quartz Crystal Unit?

A Quartz Crystal Unit is a passive element that vibrates at a constant frequency, known as a piezoelectric element. Initially, natural crystals were used, but due to increased demand, artificial crystals have become more common, utilizing materials such as silicon dioxide, barium titanate, and Rochelle salt.

When integrated with oscillation circuits, piezoelectric elements are essential in electronic devices like mobile phones, televisions, digital cameras, household appliances, and in automotive and medical equipment. The quartz crystal’s thickness and cutting method are tailored to the desired frequency range. For example, the “AT cut” method produces a quartz crystal unit suitable for a broad temperature range, with frequencies ranging from 1 to 300 megahertz.

Principle of Quartz Crystal Unit

A piezoelectric crystal generates a surface charge proportional to the applied pressure in a specific direction, a phenomenon known as the piezoelectric effect. Conversely, applying voltage causes deformation, referred to as the inverse piezoelectric effect. While natural crystals were initially used, artificial crystals, such as silicon dioxide and potassium titanate, are now preferred to meet increased demand.

Quartz crystals have electrodes attached, allowing for external current flow. The surface charge of the quartz crystal unit changes periodically in response to the current phase, leading to periodic deformation.

Uses of Quartz Crystal Unit

Quartz crystal units are widely used in various household electronic devices like mobile phones, televisions, digital cameras, and computers, due to their stable and minimal frequency fluctuations. They are also integrated into automobiles and medical equipment. Quartz crystal-based oscillation circuits are highly precise, exhibiting accuracy in the ppm (parts per million) range.

Commonly, quartz crystal units are extremely thin, ranging from 20 to 50 micrometers in thickness. Electrodes are attached to the plate surface for connection with external terminals. The thickness and cutting surfaces of the crystal can be adjusted based on the desired functions of the quartz crystal unit.

Frequency of Quartz Crystal Unit

The frequency of quartz crystal units varies with the crystal’s cutting method and thickness. Thinner crystals are used for higher frequencies, while thicker crystals suit lower frequencies. For instance, the “AT cut” method can produce units for a wide temperature range with frequencies from 1 to 300 megahertz.

Other cutting angle variations, like the “BT cut,” cover the frequency range of 7 to 38 megahertz, differing in frequency stability compared to the AT cut. Fork-shaped crystals are typically used in timekeeping applications, supporting frequencies of 32.768 kilohertz.

Load Capacitance

When integrating a quartz crystal unit into a circuit, matching the load capacitance of the circuit with that of the quartz crystal unit is crucial. Load capacitance, viewed from the quartz crystal unit to the oscillation circuit, is the virtual equivalent static capacitance value in series. To stabilize the circuit against changes in load capacitance, it’s necessary to choose a quartz crystal unit with an appropriate load capacitance value.

In practical applications, adjustments are made based on the oscillation frequency, allowable deviation, and the quartz crystal unit’s load capacitance values. However, due to various factors in real circuits, there is floating capacitance, leading to a deviation between the circuit’s oscillation frequency and the standard load capacitance frequency. Adjustments involve determining the difference between these frequencies and fine-tuning the circuit’s static capacitance to minimize this difference.

What Is an Interior Door?

What Is an Adjustable Pin Wrench?

An adjustable pin wrench is a tool used in mechanical and repair work to tighten or loosen bolts and nuts.

While conventional wrenches are designed to fit specific fixed sizes, the adjustable pin wrench, as the name suggests, can accommodate various sizes of bolts and nuts by adjusting its pins.

The adjustable pin wrench proves extremely useful in environments where bolts and nuts of different sizes are frequently handled. Operators can quickly and easily adapt to different sizes of bolts and nuts. As a result, it eliminates the need to use multiple wrenches to handle various sizes of bolts and nuts, streamlining the work process and allowing for more efficient operations.

What Is a Walchem?

Walchem is a comprehensive water treatment controller developed by Iwaki Corporation.

Walchem is a collective term for water treatment controllers developed by Iwaki Corporation. In the realm of water treatment, various indicators gauge the purity of water, including pH, ORP (Oxidation-Reduction Potential), and electrical conductivity.

pH serves as an indicator to assess the acidity or alkalinity of a solution, and in the context of wastewater, it is crucial to adjust the pH within the range of 5.8 to 8.6 to ensure that it does not adversely affect organisms and crops.

ORP measures the strength of water’s oxidizing or reducing power, indicating the adequacy of oxygen in the water. Unlike the similar indicator DO (Dissolved Oxygen), ORP is advantageous in detecting oxygen deficiency as it can take negative values.

Electrical conductivity reflects the ease with which electricity flows through a substance, and it increases when there is a high concentration of impurities such as ions. This becomes crucial in industries like semiconductor manufacturing where ultra-pure water is a necessity.

Walchem has the capability to measure and control these three indicators simultaneously in a single unit.

What Is an Underground Pipe Locator?

An underground pipe locator is a device used to non-destructively examine the location, depth, and installation direction of buried utilities such as water pipes, gas pipes, and electrical cables.

By utilizing underground pipe inspection equipment, one can confirm the presence and location of underground pipelines and structures without causing damage before construction projects on roads or buildings. This capability helps prevent excavation accidents and damage to pipelines.

There are two main types of underground pipe inspection equipment: those based on the electromagnetic wave radar method and those based on the electromagnetic induction method. The choice between them depends on the type of buried utility you want to explore.

Applications of Underground Pipe Locators

Underground pipe inspection equipment is primarily used for the following applications:

Surveying the location, depth, and direction of buried items such as water pipes, gas pipes, electrical cables, hume pipes, and PVC pipes.Confirming the presence, absence, and location of underground pipelines and structures before construction to prevent accidents and damage.

Assessing the need for repair or reinforcement of deteriorated bridge decks, tunnel walls, or other structures.Investigating changes in underground voids and strata for evaluating ground stability and seismic impact.

Excavation surveys for the discovery and assessment of the position and shape of underground relics and buried cultural properties.

Principles of Underground Pipe Locators

Underground pipe inspection equipment includes methods based on electromagnetic wave radar and electromagnetic induction.

1. Electromagnetic Wave Radar Method

This method involves emitting electromagnetic waves towards buried utilities and detecting reflected waves to explore underground objects.

Microwaves are commonly used in this radar system. When these microwaves are directed towards the ground, they travel through the medium at a constant speed and reflect upon encountering boundaries between different media.

By directing electromagnetic waves towards the location where a utility is buried, reflections occur, and the detection of these reflections allows the determination of the distance and position. This method is non-destructive, similar to X-ray inspections, without the associated risks of harmful radiation.

2. Electromagnetic Induction Method

In this method, a magnetic field is generated from the surface towards buried utilities, inducing a weak eddy current in conductive materials.

The induced eddy current is then detected to explore underground pipes. By generating a magnetic field from a coil carrying alternating current, the conductive surface of buried pipes produces overcurrent, creating an induced magnetic field.

Detecting this induced magnetic field confirms the presence of buried pipes. The strength of the induced magnetic field varies with the distance from the buried pipe, allowing measurement of the position and depth of the buried utility.

Other Information on Underground Pipe Locators

Selecting the Appropriate Equipment

The choice between electromagnetic wave radar and electromagnetic induction methods depends on the type of buried utility being explored. Electromagnetic induction is suitable for conductive buried pipes, while electromagnetic wave radar is versatile, exploring buried utilities regardless of material.

Buried utilities that can be explored using underground pipe inspection equipment include water pipes, gas pipes, electrical cable protection pipes, hume pipes, and others.

What Is a Transformer Core?

A transformer core, also known as the iron core of a transformer, refers to the central component of the transformer.

Transformers are devices used to convert voltage to the required level when utilizing electricity. The iron core is situated at the heart of the transformer, with coils wound around it.

The iron core plays a crucial role in facilitating the passage of magnetic flux. When an electric current flows through the coil, it generates magnetic flux, inducing voltage in the coil by traveling through the iron core. Typically, iron is used for the core, although other materials may be employed.

For instance, using a magnetic substance called ferrite allows for the creation of an effective core for high-frequency currents. Transformer cores come in various shapes such as “E-shaped,” “I-shaped,” and “U-shaped,” with the performance of the transformer varying based on its shape.

What Is a Tilt Switch?

A tilt switch is a device used to detect inclination or tilt.

When the switch tilts beyond a specific angle, it toggles between ON and OFF states. Providing information only about whether it is tilted, tilt switches offer features such as cost-effectiveness, easy handling, and stable operation when compared to accelerometer or gyroscope sensors used for angle measurement.

A typical tilt switch consists of a rod-shaped tube electrode containing a steel ball. When tilted, the steel ball rolls, making contact with the opposite electrode, thus completing the circuit. Tilt switches are compact and versatile in terms of installation locations.

In the past, mercury was used in the steel ball, but due to its toxicity, production and import/export of mercury-containing devices have been prohibited. Alternatives began to be supplied in the 1990s, and by the 2010s, these alternatives became widely adopted.

Currently, tilt switches are used in applications such as fluorescent lights and medical devices. However, with the ongoing development of low-cost accelerometer sensors, they are poised to become alternatives to mercury switches in the future.

What Is a Three-Phase Surge Suppressor?

A three-phase surge suppressor is a device used to protect electrical devices from voltage spikes.

It is commonly employed to safeguard the prevalent three-phase alternating current (AC) power circuits in modern power systems. These circuits utilize three sets of alternating currents transmitted through three wires, typically colored red, white, and blue, with a phase shift to the power direction.

Installed in distribution panels or control panels, the three-phase surge suppressor functions to prevent overvoltage and overcurrent when the power is subjected to abnormal conditions such as lightning surges or other voltage spikes. This instantaneous protection helps shield equipment from damage or malfunction.

When selecting a three-phase surge suppressor, it is crucial to verify the protection levels, such as the maximum current of the equipment to be protected. Subsequently, choose a surge suppressor with an appropriate voltage withstand capability and interrupting current. Using an unsuitable suppressor may lead to the loss of protective functions.

Additionally, pay attention to the environmental conditions at the installation site to ensure optimal performance.