Transducer | pressure transducer | Pressure Instruments | CVD | MEMS Sensing Technology | TruAccuracy
Whether you are measuring low-pressure airflow in a critical environment, high-pressure mobile hydraulics in OEM applications, or even ultra-high purity gases in semiconductor manufacturing, you are likely relying on a pressure transducer to keep your system running safely and efficiently. In each of these instances, the challenge is selecting the best transducer for the specific application, especially when there are so many options available to you.
Ashcroft and its parent company Nagano Keiki Co. LTD have a proven track record of reliability and excellence in pressure measurement instrumentation. All the sensing technologies discussed in this article have been designed and manufactured by Ashcroft along with Nagano Keiki, allowing us to control the performance, cost and lead time of our pressure sensors.
Read this article to learn what sets Ashcroft pressure transducers apart from the competition and why our company is the best choice for customers in many industries around the globe. You will also gain access to other valuable insights and resources to enhance your understanding of these instruments and their functionality.
When you are done reading this article, you will be in a better position to take the next step in your purchasing decision.
Proprietary technology is Ashcroft's competitive advantage in pressure transducers.
Ashcroft® pressure sensors (aka transducers or transmitters) - most of which are built in our facilities - offer advanced proprietary technology to ensure accurate, reliable and repeatable measurements. The type of technology that is used in each pressure-sensing instrument depends on the application that the instrument is measuring.
Silicon Capacitive MEMS Sensor (Si-Glas™) for ultra-low differential pressure applications.
The Ashcroft® CXLDP and DXLDP pressure sensors integrate the company's Silicon Capacitive MEMS Sensor (Si-Glass™) technology to achieve precise, consistent and stable low-pressure measurements in a wide range of critical environments including isolation room airflow and cleanroom pressurization. Some consider this sensing technology among the best in the world for low-pressure applications.
Si-Glas™ technology uses advanced semiconductor processes to create a compact silicon microelectromechanical (MEMS) pressure sensor specifically designed to detect incredibly small pressure variations in the millionths of a PSI range. While some brands use higher pressure sensors that amplify the output to reach a specific range, which can produce inaccuracies, our Si-Glas™ sensors give you the ability to range a product based on the actual range of the sensor. Plus, Si-Glas provides a true quarter-percent terminal point calibration, eliminating the need for manual adjustments.
How Ashcroft® Si-Glas™ sensors are created.
The Si-Glas™ sensor is comprised of three distinct elemental layers:
- A top layer that is made from specialized glass.
- The center layer, which acts as the actual sensor diaphragm, is manufactured from single-crystal silicon.
- The bottom layer is also made with specialized glass.
One advantage of using silicon as the diaphragm material is its elasticity which lasts until the point of failure. This allows the diaphragm to detect incredibly low differential pressures and revert to its original shape once the pressure returns to zero, minimizing the effect of offsets at zero psi.
The Si-Glas™ sensor manufacturing process:
- Metal electrodes are placed on the glass using a sputtering process, creating a section of the capacitive sensor element and providing a pathway for the electrical connection to the finished sensor assembly.
- The silicon diaphragm, which is just a few microns thick, is electrostatically fused between the two glass wafers.
The result is a Si-Glas low-pressure sensor, which is extremely sensitive, repeatable and reliable.
Figure 1. Si-Glas™ capacitance sensor.
Watch the video for an animated view of the process.
Download our whitepaper to learn more about the benefits of this technology.
Chemical Vapor Deposition (CVD) technology for mid-to-high-pressure applications.
Pressure transducers such as the Ashcroft® S1, E2 and G2 use our innovative chemical vapor deposition (CVD) sensing technology to achieve accurate and repeatable pressure measurements for mid-to-high pressure applications. This technology ensures consistent reliability and high performance across a wide range of mid to high-pressure applications that require high cycle life, vibration resistance and superior repeatability. A few examples include:
- Mobile hydraulics
- Lift, load and compressor systems
- Performance racing
- Railway, forestry and mining
- Irrigation systems
How the Ashcroft® CVD sensors are created.
Through a meticulous semiconductor process, four polysilicon strain gauges are strategically placed on a Stainless steel diaphragm. This involves laying down a layer of silicon dioxide as an insulator, applying the polysilicon strain gauge layer, and using the lithography technique to remove specific areas for resistance measurement.
Gold interconnects are used to connect the strain gauges, forming an electronic Wheatstone Bridge circuit for calibration and compensation to get an accurate output. Finally, a proprietary protective micro-coating is applied over the strain gauges using passivation.
CVD sensor-based transducers are a great option for high-precision monitoring because they can provide multiple outputs, including voltage, ratio metric and current.
Figure 2. Ashcroft® CVD technology.
Watch the video for an animated view of the process.
KP18 sensor technology for lower pressure and absolute measurements.
Another sensing technology used by Ashcroft in its pressure sensors is the KP18 isolated Piezo Resistance Module. This technology can be found in several Ashcroft pressure transducers, including the E2 (for general industrial applications) and G3 (a great option for mobile hydraulic applications). There are two styles of the KP18 sensor:
- KP18-S01 for general purpose
- KP18-150 for a flush diaphragm
These sensors incorporate a silicon piezo sensor die, which is among the most stable and reliable on the market. One of the most important features of the KP18 is its ability to measure absolute pressure.
How the KP18 sensors are created.
Figure 3. KP18 assembly process.
Integrated Sensor Platform technology for mid-to-high-pressure applications.
The core technology used in the Ashcroft® E2G Pressure Transducer is called the Integrated Sensor Platform (ISP). This technology was developed by the company to expand Ashcroft's digital output offering in our E2 line of transducers.
For this product, we pre-calibrate the sensors over a compensated temperature range for performance and accuracy. Our approach is to separate the temperature compensation of the sensor from the final product so we can compensate large batches of sensors separately in a single process. We are then able to inventory compensated sensor modules which allows Ashcroft to deliver the E2G faster than most standard industrial transducers.
We use new fiber laser technology for welding and wire stripping technology to change wire lengths without having to rely on third-party suppliers. So a lot of the techniques in manufacturing allow us to have the control of producing and customizing that product at a faster pace for the customer.
Ready to learn more about pressure transducers?
Now that you know how Ashcroft's pressure transducers are made with proprietary technology and offer numerous advantages, you may be ready to deepen your knowledge on the subject. We've compiled a few more articles below for your reference. They provide answers to some of the common questions we get about pressure sensors and the technology that makes them unique.
- What is CVD Technology and Why is it Important in OEM Applications?
- MEMS Pressure Transducer Sensor Technology
- Choosing the Right Pressure Sensor: 5 Factors to Consider
- How Much Do Pressure Transducers Cost? (6 Factors Impacting Price)
For personalized assistance, feel free to reach out directly to one of our experts.
In the meantime, download our guide, 5 Mistakes OEMs and System Integrators Make When Selecting Pressure Sensors.
