Alright there, mates; if you’ve been delving into the world of pressure sensing, then you’ve probably noticed that electrical sensors come in two kinds: piezoresistive and piezoelectric. Naturally, it’s easy for armatures to confuse between the two, but if you don’t get the right sensing equipment, you won’t be able to perform the measurement task at hand. It’s all in the name, alright. Here is a look.
What Are Piezoelectric pressure sensors?
These kinds of sensors contain material that generates electrical charge when subjected to mechanical force. This electrical charge is proportional to the amount of mechanical force (pressure) being applied. The charge is then amplified and conditioned, then converted into a voltage signal. The signal fluctuates as the mechanical force being applied changes. The piezoelectric material is typically barium titanate, lead zirconate, or quartz crystals.
Advantages and Disadvantages of Piezoelectric Pressure Sensors
Piezoelectric pressure sensors are used to measure dynamic pressure in various applications ranging from liquid pressure measurement, oil and gas exploration, HVAC systems, wind farm turbines, etc.
They are typically used in closed loop systems to generate signals that allow alarms and other controllers to regulate a system sans manual intervention. As mentioned, the voltage signals vary according to the level of pressure being applied.
However, piezoelectric pressure sensors tend to be a bit expensive compared to piezoresistive sensors, which we discuss below. However, they are typically more sensitive and designed to function in a wide range of operating temperatures, offering more accuracy in medical diagnosis, sound instrumentation, etc.
What Are Piezoresistive Pressure Sensors?
Piezoresistive pressure sensors do exactly what their name suggests: they measure the change in the electrical resistance of a material when a mechanical force is applied. The change in electrical resistance is proportional to the amount of force being applied and is obtained, amplified, conditioned, and converted to voltage signal output.
Unlike peizoelelectric sensors that use ceramic or quartz materials, these sensors use semiconductors such as silicon, boron, transistor, and germanium.
Advantages and disadvantages of piezoresistive pressure sensors
Piezoresistive sensors are used to measure pressure in industrial, and medical fields; they produce linear signals that are easy to process and get accurate readings across a wide range of pressure values.
The semiconductors used in piezoresistive sensors make this equipment durable and stable over time. Indeed, they can withstand harsh environments and conditions such as vibration, shock, and even dynamic variation in pressure without reducing performance.
Piezoresistive sensors are typically inexpensive to boot! Unlike piezoelectric sensors, which use ceramic and quartz materials that can be expensive to obtain, these sensors use commonly available semiconductors, making them easy to manufacture.
Piezoresistive sensors can be integrated into electrical systems without too much signal-conditioning circuitry. They are easy to use and can be adapted into various designs without too much hassle. They also consume low amounts of power, making them suitable for use even in battery-powered devices.
That said, the piezoresistive materials are not as durable as piezoelectric materials. Moreover, because they only have moderate sensitivity and may not generate readings that are as accurate as those obtained using piezoelectric pressure sensors.
Applications of Piezoresistive Pressure Sensors
Piezoresistive sensors are also used to detect vibration in engines and other structures. If a part starts vibrating suddenly, it could be an indicator of mechanical or structural damage, and fixing it immediately can help ensure smooth aircraft operations and also prevent accidents.
In environmental monitoring, piezoresistive pressure sensors are used to monitor atmospheric pressure and generate data useful in weather forecasting and storm predictions. They are used in water bodies and storage tanks, too, to measure water levels and generate alarming signals in case of floods. They are also used in agriculture to measure the amount of moisture in soil and determine if irrigation is required and when to stop, ensuring sustainable water usage.
To cap it, pressure transducers can be of the piezoelectric or piezoresistive nature. The former generates an electrical charge when pressure is applied, while the latter measures the difference in resistance due to a mechanical force.
Generally, both types of sensors offer accurate readings in a wide range of environments, but piezoresistive pressure sensors are the most affordable. They are also easy to use and can be adapted into any design and integrated into electrical systems seamlessly.
If you are looking for piezoresistive pressure sensors, we will be happy to talk to you about our products. Contact us via email or give us a call to speak with an expert from MicroSensor.
