February 28th, 2011
Pressure sensors are devices that determine the pressure of the given medium. While not many people know, pressure sensor devices are widely used in daily operations. These sensors are helpful in monitoring fluid pressures in hydraulics, engines and pipes. To determine the pressure of solids and gases, special types of sensors are also available.
The size of sensor devices is usually about one cubic inch. However, some special types of sensors can also be more than hundred times smaller. One best example is the one used in microelectromechanical systems. The latest pressure sensors work on simple principle called as piezoresistance.
The changes in pressure cause the substance to conduct electricity at a specific rate. This leads to flow of charge related to a certain pressure level. This charge is generally fed to a wire that leads to the display and control panel for human analysis.
Pressure sensing technology
The conventional pressure sensors used resistors, strain gauges, metal alloys or polycrystalline semiconductors as a resistive medium. These materials can only conduct electricity based on their structure’s deformation. As the rise in pressure does not create any type of linear magnitude in deformation, special calibration technique must be used for finding out the real pressure.
A number of different pressure sensors are available for different applications and uses. An absolute pressure sensor measures the overall pressure of the system, keeping vacuum as a point of reference. A gauge sensor is another type of pressure sensor that measures pressure while taking ambient atmospheric pressure as reference. Different types of pressure sensors are also available for measuring two different contacts.
February 28th, 2011
Level sensors are widely used across different industrial sectors. Their application includes determining level of substances that flow including powders, liquids, slurries and granular materials. Due to gravity, these substances flow into their respective containers. The measuring substance can be in the natural form like a river or lake or within a container.
Level measurement can either be continuous or point value. The continuous level sensors measure level of the given medium in a specified range. On the other hand, point level sensors only determine whether or not, the substance is above or below the sensing point. The main purpose for using point level sensors is to detect extremely high or low levels.
Numerous physical variables and applications affect the selection of level monitoring techniques. When selecting level sensors for industrial or commercial purposes, look for the following specifications;
• Pressure or vacuum
• Physical phase (slurry, liquid or solid)
• Acoustical or electrical noise
• Dielectric constant and density of the medium
The application of level sensors is also an important consideration. Ease of calibration and programming, appearance, cost, accuracy and response rate are other specifications to look for. The mounting of level sensor instruments, its physical size, monitoring or controlling of continuous or discrete levels are other important considerations.
The measuring range, process operating conditions, communication interface and instrument style are some specifications that can help you choose the right level sensors that suit your application needs.
February 27th, 2011
Temperature sensors are nothing but measurement instruments that ascertain the exact temperature by sensing certain physical characteristics. These may include electromagnetic fields, thermal radiation or electrical resistance.
The main types of temperature sensors explained
There are different temperature sensors available on the market. Examples of some are bimetal switches, liquid level sensor and thermistors. Thermocouples contain two wires made of different metal each. These wires are soldered to a junction, which is left exposed on the measurement instrument. The other end of the wire is connected to a reference junction. Thermocouples are available in four varieties. There are companies who have Constantan, Chromel and Alumel as trademarks.
Resistance temperature sensors are used to detect changes in temperature. They convert elements into current signals using a thin-film serpentine. Thermistors are very sensitive but have a confined range of temperature. The two main types of thermistors are positive temperature coefficient and negative temperature coefficient. There are other temperature sensors that are available with alarms. Temperature sensors are also available in digital and analogue properties.
Application of temperature sensors
Temperature sensors are used in varied industries. They are commonly used in chemical labs, the manufacturing sector, hospitals, in air conditioning units as well as in alarm systems. They are very important in gauging the correct temperature reading.
Temperature sensors are also used in airplanes and in vehicles to gauge engine temperatures. These sensors help detect overheating of machines. In hospitals doctors use temperature sensors to keep record of a person’s body temperature. Households use temperature sensors to set the room temperature accordingly.
February 27th, 2011
Pressure sensors are as simple as their name suggests. They are devices that are used to measure pressure in minute or major quantities. With the help of pressure sensors you can accurately measure the pressure of a liquid or anything that involves force.
Appearance and functioning of pressure sensors
Pressure sensors have various applications and some can be as simple as a spring scale. When pressure is applied, it will cause the arrow to swing. These scales are not as sensitive as modern day pressure sensors. The latest pressure sensors can give an accurate output, which can be measured by electronic gadgets.
A brief guide on piezoresistive pressure sensors
Piezoresistive materials have great features due to which they are widely used in pressure sensors. Piezoresistive materials possess a property that allows them to regulate their resistance according to the flow of current. They display such properties if they are compressed or strained.
The functioning of piezoresistive pressure sensors
A piezoresistive pressure sensor contains numerous layers of silicon that is embedded between their protective surfaces. Their surface is usually connected to a Wheatstone bridge. A Wheatstone bridge is capable of detecting small differences in the resistance levels of an object. The Wheatstone transmits small amount of current that flows through the pressure sensor. A change in resistance can alter the levels of current passing through the pressure sensor.
A Wheatstone bridge is used to detect this change and can give you an accurate reading about the change in pressure.
February 26th, 2011
A pressure transducer measures the amount of exerted pressure on the sensor and sends out electrical signals. They are mainly accustomed to calibrate the pressure applied by a gas or liquid under varying conditions. They are used in the manufacturing aeronautic vehicles. They come in varieties depending on specifications and application such as measurement of pressure exerted in vacuum, gases or liquids and extreme temperature. The entered measurements are fed in a data logger. Here we have discussed specifications of the three most common types.
Pressure transducers with mili-volt output
They are the least expensive type. They are ideal for short distances and the environment with less electrical noise. A uniform power supply is essential for the most exact readings. Actual output is proportional to the power or excitation input.
Pressure transducers with volt output
They are relatively less vulnerable to electrical disturbances and do not get affected by EMI and RFI distortion. Steadiness of power supply is not a compulsory requirement.
Pressure transducers with mili-ampere output
They are also referred to as pressure transmitters. Often used for signal transmission over long distances, since it is least vulnerable to electrical noise and fluctuations in power.
Pressure transducers can be further categorised according to type of sensor and type of pressure measured. As an example, Absolute sensors sense pressures in absolute vacuum. Gauge sensors measure pressures in relativity and differential pressure sensors measure the differences between two different pressures in one system.
February 26th, 2011
There are many different types of temperature sensor. Be it as basic as a thermometer or highly developed as electrical heat recorders, these temperature sensors are used for a variety of industrial purposes.
The more superior form of contact measuring is known as resistance temperature detectors (RTDs) and thermocouples. The temperatures are typically measured in liquids or through physical contact with the target’s surface.
The functioning of a resistance temperature detector
Contact measurements are not always required and there are other alternate ways to measure heat. There are new temperature sensors in the market that can measure heat without any physical contact. Normally this feat can be established with the use of air ionisation or infra-red technology.
When selecting a sensor you will have to consider a number of possibilities that can make it difficult to make a decision. An important aspect of this process is the temperature range that has to be measured. This depends on the accuracy levels offered by your device and the time taken by it to show you results. For those who want an accurate reading, an RTD sensor will serve their purpose.
Thermocouples, on the other hand, are an affordable and cost effective option.
The RTD uses the increased resistance caused by heat to give us an accurate measurement of the object’s temperature. RTDs are made of metals such as copper, nickel and platinum. The chemical property of the metal is of crucial importance in the selection process. Nickel and copper are used to measure low temperatures, whereas platinum is used to measure extreme temperatures.
As you are now familiar with the temperature sensors, this will help you choose the right type of sensor for your needs.
February 25th, 2011
Are you planning to set up your own industrial plant or factory? If you want to facilitate the smooth functioning of industrial processes then pressure transducers are a must. However, for this first you should know what pressure transducers are and what they do.
Pressure Transducers – The basics explained
Pressure transducers, in simple terms, are devices which sense the pressure applied on different industrial equipment. They can accurately calibrate the pressure applied by gases or liquids. Keep in mind that they can also sense the pressure under variable conditions.
This is the precise reason why pressure transducers are used in both aeronautics and oceanographic vehicles. The conditions are extremely variable in both cases and only a pressure transducer can measure the pressure in such conditions. Different types of pressure transducers are manufactured, keeping in mind the specific industrial conditions.
For example, a distinct pressure transducer is available for sensitive industrial environments exposed to an intense range of temperatures.
If you are looking for an economical transducer, then you should opt for the strain gage type. This particular transducer works on the principle of pressure exerted which causes strain on instrument gages. The transducer then accurately measures the strain caused.
Understand that pressure transducers are also available in different types. Absolute, gauge sensors, differential pressure sensors and sealed sensors are some of the various types of pressure transducers.
Browse through the features of each pressure transducer and choose one which meets your specific needs and requirements.
February 25th, 2011
Most people are clueless about the different technologies utilised in manufacturing plants. They also have little knowledge about the calibration of equipment which is an integral part of the industry. Pressure sensors are usually used for the exact measurement of pressure.
Such high-accuracy pressure sensors provide the accurate measurement and calibration of pressure instruments. Some of the common devices include pressure transducers and pressure transmitters. Pressure sensors and calibrators are usually employed for metrology and laboratory use.
Pressure calibration instruments are used for various different functions. For instance, they are used for increasing the volume of industrial production. On the other hand, they might also be used for other industrial applications as well. Some of the pressure equipment used is as follows:
Pneumatic calibration hand pumps
These devices are generally used for producing exact air pressure set-points. They are also used for regulating the pressure devices or instruments along with a pressure indicator.
Digital test gages and high pressure calibration hand pumps
Digital test gages are used for attaching it to the top of the hydraulic calibration hand pumps. It is therefore used to calculate the exact pressure. High pressure calibration hand pump device is utilised to produce the calibration pressure along with fittings. Therefore, you can easily attach it to a pressure indicator.
Secondary pressure standards
This equipment is widely used in calibration technologies and other instruction workshops. Secondary pressure standards can also project accurate pressure readings.
Calibration standard pressure sensors
This equipment is used for accurate measurement. These devices are used in calibration laboratories. Some of the common calibration pressure sensors include differential pressure, transducers and transmitters.
Therefore, consumers should select a pressure sensor device on the basis of their requirements. However, they should not compromise on the quality.
February 24th, 2011
Pressure sensors are pressure sensing devices. This device can measure the pressure of gases as well as liquids. Pressure in general terms means the applied force to prevent the expansion of a fluid. It is described in force per unit area.
Pressure sensor – Uses and applications
A pressure sensor performs as a transducer and transmits a signal as a function of the pressure applied. It is also used as a monitoring device in a number of manufacturing plants. Due to its pressure sensing capabilities, it is also used in marine research plants along with production control.
Pressure sensors, in these industrial plants, facilitate positive results. Moreover, these devices can also be used to ensure permissible levels of safety. As mentioned, pressure sensors are used in different manufacturing plants. They are primarily used to keep a track of the overall pressure applied. In this way, workers in an industrial plant can ensure that the applied pressure stays within the prescribed limits.
Constant monitoring, thanks to pressure sensors, ensures that the desired end results are obtained. It also ensures that the machine does not malfunction due to the application of more pressure than required.
Gauge liquid pressure
A pressure sensor can also be used to measure liquid pressure in industrial environments. It is used in vehicles or automobiles for monitoring the oil pressure. Thus, a proper balance of oil pressure is maintained which allows the smooth operation of vehicles.
Pressure sensors indeed form an integral part of many different industrial and manufacturing processes.
February 24th, 2011
You may have heard the name of the device called the pressure sensor. These devices are used to measure the absolute pressure in manufacturing plants. Pressure sensors provide the users with exact details when it comes to measuring the pressure levels of different devices. An excessive application of pressure can result into untoward incidents and this is the reason why pressure sensors are used to avert any major tragedy.
The following are some of the different applications of pressure sensors:
Cranes and earthmovers
Pressure sensors are used in cranes or earthmovers. To be precise, they are used in equipment which is operated with hydraulic systems. For instance, they control movement such as gripping or applying force. Pressure sensors therefore track and offer pressure feedback to this equipment. These devices are used to track the hydraulic fluid level. This plays an important role in the overall maintenance of different equipment.
The user is thus notified whenever the pressure level in the equipment exceeds a specific safe level.
Measure pressure in gas applications
Pressure sensors are also used to monitor or measure the overall pressure in gas based applications. The compression of gas usually causes an increase in temperature. Pressure sensors in this case track the exact pressure of the air before it is transferred in the gas equipment.
Similarly, pressure sensors are also used in liquid based applications for monitoring the volume and liquid density.
Thus, the useful nature of pressure sensors is evident from the above mentioned applications.