Choosing the Best Pressure Sensor

While choosing the pressure sensor for your design, you have to look for some critical parameters, that are very important. Based on these parameters, you have to choose the available sensors. Of course, you have to look through the economical angle also.

These are the main parameters to look for –

Accuracy – First and foremost parameter is accuracy. What kind of accuracy you are looking for? Is your pressure very dynamic? Changing very fast? Or is the change slow? What is the rate of change? Do you have to continuously monitor the pressure and record the data or you have to measure it periodically? Based on your process, you have to decide, what kind of accuracy you are looking for. This will decide the type of sensors. Sensors are available with 0.5% accuracy to 0.1%, 0.25% and 0.05% accuracy. As the accuracy increases so as the prices.

Output – After you decide the accuracy, you have to look for the kind of output. These sensors come with Voltage and current output.

Sensors with voltage output, are generally used,where the sensors and measuring instrument or Data Acquisition system, both are near to each other. These sensors give out put in mV (millivolt-1000th of a volt) in the range of around 0 – 30 or 100 mv. Some sensors also have internal amplifier that offer output in the range of 0-5V or 0-10V. These kinds of sensors generally use strain gauges. The sensors with inbuilt amplifiers also provide internal zero and span adjustment facility. Though, because of these internal amplifiers, the frequency response is slow.

Sensors with current output are generally used when the distance between sensors and the measuring instrument or Data Acquisition system is more, like in big plants. As the output is in current form, they have high noise immunity. They also provide zero and span adjustment besides offering high frequency response.

Environment – The location of the sensors. This criteria is also very important in deciding the type of sensor. The operating environment will decide the mechanical structure of the sensor. If the sensor has to be used in harsh environment, it will have extra protection and because of these, it will cost more. While the sensors,which are used indoors,cost less.

Fitting – This is also an important factor. How you are going to fit the sensor? Does the sensor come with easy fitting couplings? Or you have to make a spatial mechanical arrangement for fitting? You have to consider all these factors before considering a particular type of pressure sensor which will fit into your design.

Pressure Sensors Work

Data on the possible applications of pressure transducers is also provided. There are many applications of these devices, especially in the industrial setting although they are also helpful in monitoring the tire pressure of automobiles. A frequent design for them, such as the Keller pressure sensors, is one that makes use of piezoresistive materials. These materials have the unusual characteristic whereby their resistance changes correspondingly with the force or pressure that is applied on them. These materials make up the key component of the sensors, which is the sensing diaphragm. This diaphragm is designed in such a way that its movement depends on the amount of pressure that is applied. However, it is also common for people to inquire on “how do pressure sensors work?,” because they realize that they are part of the systems for continuously monitoring the pressure of their car tires.

For those who are inquiring “how do pressure sensors work?” and are also interested on the mechanisms of the tire pressure sensor, this is a kind of technology that is designed for safety. It warns the driver in the event of a low tire pressure. This type of tire pressure monitoring system (TPMS) was mandated by the National Highway Traffic Safety Administration for all vehicles that are sold after 2008. There are two categories for TPMS and these are the direct and indirect systems. The direct TPMS has pressure transducers installed for every tire to constantly check on the tire pressure. However the indirect TMPS calculates the air pressure in the tire by measuring other variables, including the tires’ revolution per minute.

They can be of various kinds and include the differential, gauge, air, piezoresistive, digital, vacuum, and absolute pressure sensor. However, one of the most common designs uses piezoresistive materials, which means that the current is directly proportional to the pressure applied. The material is normally utilized is the semiconductor silicon. Several thin wafers of silicon are sandwiched in between protective materials.

So, how do pressure sensors work when they are specifically applied for ensuring that car tire pressure is within the proper range? Well, there are two basic components of the direct TPMS and these are the radio transmitter for sending the collected information to the vehicle’s on-board computer and the pressure sensor that is placed within the tire rim. Radio transmission is through the car antenna, which detects the signals and then routes them to the central monitoring system. However, for the indirect type of TPMS, the pressure transducers are not needed. The amount of pressure in the tires is estimated by determining the diameters of the tires. In turn, the diameters of the tires are calculated by using the rotational speed as input. If the on-board computer detects a somewhat faster rotational speed for one of the tires, it warns the driver that this particular tire has a lower air pressure because it has a smaller diameter.

The Kinds of Sensors

Temperature sensors are the most common type of sensors. They are meant to detect temperature or heat. There are simple on/off type thermostatic devices which are used in domestic hot water systems. The highly efficient temperature sensor is used to process control furnace plants. The amount of heat will be measured by an object or system and physical change to the temperature will be measured, and either analogue or digital output will be produced.

Temperature digital panel meter is the most versatile meter in the market. The temperature meter can be used to process a wide variety of processes and applications. There are meters where the intensity of the display can be adjusted as per the ambient light. If there is direct sunlight, the visibility will be reduced. The control push buttons can be used so that programming and setup can be accomplished in an effortless manner. The temperature can be measured in either degree Fahrenheit or degrees Celsius. There are low-cost temperature digital panels as well as expensive digital panels. There are meters which come with large displays so that you can find the reading from a distance very easily.

Angle measurement – The angle or slope can be measured in a very efficient way with the help of an inclinometer. The digital inclinometer manufactured by a reputed brand will fulfill your needs in a very efficient manner. You should go through the wide range of digital inclinometers, slope meters and digital display units which are meant for inclinometer sensors.

The products can be customized as per your needs. If you would like to use the meter for a specific purpose, you can go for customized meters. There are standalone products as well as battery-powered inclinometers. Some units come with a display built into the product. There are units with separate sensors and remote display units.

Pressure sensors – There are different kinds of pressure sensors. The classification of pressure sensors will take place on various parameters. There are temperature ranges of operation which will guide you to choose the best pressure as per the conditions. The pressure sensor will deliver reading when pressure is applied to the sensor. The sensor will break when it crosses the designated pressure. If you go for an Absolute pressure sensor the measurement of pressure will take place relative to perfect vacuum. In case of gauge pressure sensor, the measurement will be relative to perfect vacuum.

Load sensors – By using a Load sensor, you can measure events or changes in the environment. The information will be sent to the processor so that it will be processed further. The actuator will get a signal from the computer, and the corresponding output will be produced. By using the sensor, the signal will be converted from analog to digital in an efficient way. There are sensitive sensors which can be used for special applications. In case of a biosensor, the analysis will be done by a biological component. Biological sensors are present in all living organisms. A chemical sensor will provide the chemical proposition of environment.