Seta Davidian

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Pressure Sensors for Critical Environments

Posted by Seta Davidian on May 11, 2021 1:37:54 PM

Pressure Sensors for Critical Environments

For many decades, Servoflo has been helping companies meet their pressure sensing measurement needs for a variety of applications, including those in critical environments. Our pressure sensors range from 0.15 psi to 9000 psi (600 bar) in compensated, uncompensated, amplified, and unamplified modules. With our broad lineup of sensors for critical environments, we can help you find the perfect sensor.

Managing Critical Environments

When you need to maintain tight control over critical spaces to protect patients, personnel, and assets, managing room pressure and controlling the environment is crucial. Areas such as cleanrooms, laboratory equipment, negative-pressure ambulances, and hospital isolation rooms all need environment controls and a way to warn personnel of potential problems or automatically trigger adjustments.

Cleanrooms

cleanroom pressure sensors

Sensors can provide early warning of changes that can impact performance – such as differential pressure between a cleanroom and an outside environment. 

Maintaining a specified differential pressure between the cleanroom and outside environments, such as an isolation layer, keeps dust and contamination out. Cleanroom sensors can be used to provide continuous environmental pressure monitoring. When a change is detected, it can signal control units to automatically start fans to boost the cleanroom. 

Laboratory Equipment

biological safety cabinet pressure sensorsLaboratory equipment such as biological safety cabinets and fume hoods have strict safety requirements to prevent noxious fumes or contagions from impacting lab personnel. Pressure sensors can provide feedback as HEPA filters load to increase blower speed to maintain safety.

Ambulances

Pressure sensors can provide an early warning for changing conditions that can impact performance and safety in negative-pressure ambulances. This is especially important for ambulances used to help safely treat and transport patients with potentially infectious diseases. The negative pressure filters the air so that only outside air can flow to the inside.

Inside air is passed through a biosafety exhaust purification system to minimize cross-infection of medical staff during treatment and transport. Sensors for ambulances monitor conditions to provide a safer environment.

Isolation Rooms

Hospital isolation rooms require special air handling equipment which can provide either positive or negative pressure. Negative pressure keeps air from flowing out of the isolation room while positive pressure prevents the transmission from the outside environment.

In either case, isolation room sensors ensure the pressure is consistent to keep patients and medical professionals safe.

Pressure Sensors From Servoflo

ai164-newHTC52-headerTypical pressure ranges for critical application are extremely low, under a few inches of water column. We have put together a large selection of pressure sensors within that pressure range with a variety of digital and analog outputs to give maximum flexibility for critical containment applications. In addition, many kinds of packages are available for pressure sensors, from board mount as part of a control board, to fully packaged pressure transducers for duct installation.

Review our list of suggested pressure sensors for critical containment applications

For fastest results, use the Pressure Sensor Selector Tool to get help determining the right sensor for your unique application.

Other Sensors from Servoflo

Choosing the right sensor for critical environments is an important decision. In addition to pressure sensors, Servoflo also offers a wide selection of mass flow sensors, humidity sensors, and other environmental sensors to meet the needs of various applications including medical, HVAC, automotive, cleanroom, and more.

The Servoflo Advantage

Servoflo offers a large selection of sensors that provide our customers with value in terms of price, performance, and reliability. When you work with us, you get experienced, knowledgeable, and accessible salespeople. We know your industry and can help you find the perfect sensor you need to get the job done right.

Contact Servoflo today for help choosing the best sensor for your critical environment.

HVAC Applications

Posted by Seta Davidian on Apr 12, 2021 11:50:06 AM

HVAC sensors are essential for maintaining set conditions within indoor environments. These innovative technology pieces allow HVAC equipment to measure environmental factors and adjust accordingly based on set parameters. The HVAC sector relies upon sensors in diverse settings to facilitate varying degrees of control over airflow, temperature, and more.  

Servoflo distributes a wide variety of sensor types, including humidity, pressure, and mass flow sensors. This blog post will discuss some of the most frequently used sensor types and their HVAC applications.

HVAC Applications

HVAC systems can be large energy consumers, so choosing the right sensors is essential to controlling your environment efficiently. Utilizing ventilation sensors can have a significant positive impact on energy costs.  Sensors allow precision control of many indoor environmental factors, such as humidity, air quality, energy efficiency, and more.

There are many sensor applications within the HVAC industry. Some of the most common HVAC sensor applications include:

AdobeStock_279700059

Ventilation Monitoring

Monitoring a facility’s ventilation systems helps maintain good air quality, control humidity, and remove potentially harmful gases and pollutants. Controlling the amount of outdoor air that enters a space will prevent potentially expensive problems, such as mold growth from high indoor moisture levels. Ventilation monitoring is also essential for the proper filtration of smoke, dust, and odors. 

Maintaining Indoor Air Quality 

There are several types of sensors that can help measure and maintain indoor air quality. Sensors measure humidity, temperature, room pressure, and other factors that affect the air quality and comfort level in a space. Monitoring ventilation and controlling pressurization can have a significant impact on indoor air quality. 

Providing Temperature Comfort Indoors

One of the essential functions of sensors used in the HVAC industry is temperature control. Adequate heating and cooling are critical for indoor spaces, and sensors allow indoor temperature monitoring to ensure control systems are functioning correctly.

HVAC Sensor Types

Pressure sensors monitor for unexpected pressure drops or increases in a heating or cooling system. This careful monitoring facilitates optimal airflow, heating, and cooling functions, all of which are essential to providing good air quality. There are many types of pressure sensors that used throughout the HVAC industry:

  • Building Automation Sensors. Building automation sensors measure differential pressures, allowing automated HVAC systems to adjust settings accordingly to maintain optimal system pressure. This technology allows the room or building to work at optimal efficiency, saving energy and resources. 

  • Variable Air Volume Sensors. Variable air volume sensors allow large spaces to maintain consistent air temperature by measuring air volume and precisely controlling it to deliver proper air motion, distribution, and dilution.

  • Central Air Conditioning Filter Sensors. These sensors measure the pressure on either side of an air conditioner’s filter and use that information to determine when the filter screen needs cleaning or replacement. When the sensor detects reduced airflow, it sends a signal that the filter requires maintenance. 

  • Duct Static Pressure Sensors. Duct static pressure sensors monitor natural gas pressure, making them an essential component in natural gas applications. Low pressure impacts the ability to use and move natural gas in a system, while high pressures create a risk for a gas leak or explosion. 

  • Boiler and Burner Sensors. Controlling the air pressure in boilers and burners is essential for ensuring efficient combustion and regulation of fuel. Pressure sensors measure the air pressure throughout the supply channel and allow users to control the oven’s atmosphere. 

  • Data Center Sensors. Data centers require critical pressure, temperature and humidity measurement to keep networks running smoothly. Our various sensors chosen here are ideal for data center environmental monitoring.

  • Critical Environments Sensors. Cleanrooms, negative pressure rooms, biological safety cabinets and fume hoods require pressure sensors to maintain personnel and product integrity.  Typically low pressure monitoring is used as part of a control system.

  • Environmental Monitoring & IAQ System Sensors. Instruments for testing environmental and indoor air quality measure various parameters such as humidity, temperature, room pressure and more. Servoflo offers a variety of pressure, humidity and temperature sensors that can be monitored remotely.

HVAC Sensors From Servoflo

There are numerous types of sensors used throughout the HVAC industry. Choosing the right sensor will significantly impact your facility’s ability to control air quality, energy efficiency, and temperature. Servoflo is proud to supply the HVAC industry with sensors for nearly every relevant application. Contact us today and allow us to help you identify the right solution for your needs.

How Does a Humidity Sensor Work?

Posted by Seta Davidian on Mar 2, 2021 1:52:43 PM

What Is a Humidity Sensor?

humidity-group-newHumidity refers to the amount of water vapor present in the surrounding air. Humidity sensors are devices that measure moisture and air temperature in an environment and convert the data into a corresponding electrical signal. Modern humidity sensors are highly adaptable and come in many shapes and sizes, from miniature sensors installed in cell phones, to larger, industrial-grade systems. 

 

How Do Humidity Sensors Work?

Typically, humidity sensors contain a humidity sensing element and a thermistor, which is used to measure temperature. There are three main types of humidity sensors, each of which monitors small changes in the atmosphere to calculate humidity. These types include:

  • Capacitive. Capacitive humidity sensors are linear and measure relative humidity from 0% humidity to 100% humidity. They do this by placing a small metal oxide strip between two electrodes. As the level of humidity changes, the oxide's electrical capacity changes along with it. 
  • Resistive. Resistive humidity sensors measure humidity through the use of ionized salts between two electrodes. The ions in the salts measure the electrical impedance of atoms. As humidity levels change, so does the resistance of the electrodes.
  • Thermal. A thermal sensor utilizes a dual sensor system to measure humidity. One thermal sensor is housed in a layer of dry nitrogen; the other freely measures ambient air. The resulting difference between the two measurements represents the level of moisture in the air. 

Humidity Sensor Applications

Humidity sensors are used across several industries to protect equipment and ensure safe and comfortable environments. Common applications include:

 

  • Meteorology. Meteorological departments rely on humidity sensors to gauge accurate weather conditions in their respective areas. 
  • Medical. Many lifesaving medical devices rely on humidity sensors to regulate moisture. Ventilators, incubators, sterilization equipment, and more require careful moisture regulation to ensure safe and sterile function.
  • Automotive. Vehicles use humidity sensors for purposes such as air intake in the engine and climate control inside the vehicle.
  • HVAC. Humidity sensors are critical to climate control functions found in residential, commercial, and industrial HVAC systems.  
  • Manufacturing. Manufacturing equipment for food processing, textiles, paper, and more require humidity sensors to control the amount of moisture in the air and ensure the quality of their finished products.

Aside from those listed above, other industries that rely on humidity sensors include pharmaceutical, agriculture, electronics, and more.

 

Humidity Sensors from Servoflo

Humidity sensors measure the amount of moisture in the air to regulate environmental conditions for a variety of industries. At Servoflo, we offer a wide range of relative humidity sensors, humidity indicators, and humidity sensing elements designed for use in various applications. For more information, or to find out which humidity sensor is right for your needs, contact us today

 

Download Our Humidity Sensor Selection Guide

 

 

Topics: Humidity Sensors

Dye-Sensitized Solar Cells

Posted by Seta Davidian on Feb 22, 2021 11:42:58 AM

What is a Dye-Sensitized Solar Cell?

dsc-header-1Solar cells convert solar light energy into electricity, but traditional models can be inefficient in some applications and environments. Dye-sensitized solar cell (DSSC) devices are optimized to generate power, even from ambient light energy. By affixing these cells to sensors, users can equip instrumentation, building monitoring systems, signage, structures, and more with the self-powering devices that do not require ongoing attention. The dyed cells enable high-efficiency energy production, even in low sunlight conditions.

These solar cells are commonly used in environments where other forms of energy production and storage — such as wired power or batteries — aren't possible. This includes any projects requiring a high number of sensors spread across a large surface area, remote and inaccessible locations, and areas in sub-zero temperature environments. 

 

How Do Dye-Sensitized Solar Cells Work?

There are four key layers that sunlight passes through in dye-sensitized solar cells:

  1. The electrode: First, sunlight or artificial light passes through the glass conductor on the cell surface and through the electrode.
  2. The dye: Next, it touches the dye layer. The dye is photoactive and produces electricity once the light sensitizes it. The light and dye layer excite the surrounding electrons, and the dye pushes the electrons into titanium dioxide within the solar cell.
  3. The electrolytes: From there, non-crystalline titanium dioxide conducts the electron away, where a chemical electrolyte conducts the electron back towards the dye layer. The continual movement of electrons results in usable power.
  4. The counter electrode: This component catalyzes the electrolyte's redox reduction. By including a counter electrode, the solar cell is more stable and offers better performance throughout its lifespan.

More simply put, ambient light triggers the dye to start exciting and moving electrons. That energy can then be used by sensors, electrical devices, and more.

 

Features of Dye-Sensitized Solar Cells

dssc-sunlightDye-sensitized solar cells are remarkable because of their ability to operate in non-ideal light conditions, such as environments with relatively little light or poorly angled light. Modern dye-sensitized cells also offer these key benefits:

  • Simplified production. Dye-sensitized solar cells are cost-efficient to produce. Combined with the extended lifespan, the return on investment grows over time.
  • Energy efficiency. These solar cells have a high-conversion efficiency that's aided by the dye. Structures and signs can easily be outfitted with small panels that provide sufficient power. Fujikura DSSC products can operate anywhere from 100lx to 100,000lx.
  • Optional features. Dye-sensitized solar cells can be modified to meet a wide variety of application needs. 

Applications for Our Fujikura DSSC Products

Dye-sensitized solar cells are ideal for "fit and forget" applications — use cases when the structure may not be routinely inspected or visited, or in busy environments where maintenance demands are inconvenient. Some of the most popular applications for our dye-sensitized solar cells include:

  • Warehouse management. Dye-sensitized solar cells can power sensors for refrigeration units, humidity monitors, inventory monitors, and more. These devices provide direct power without the need for wiring.
  • Optimizing commercial HVAC systems. Building managers can monitor HVAC conditions such as power consumption, humidity, and moisture to stay ahead of developing malfunctions. Our DSSC products reliably provide power to sensors, so there's minimal risk of losing oversight.
  • Sensors and reporting systems. Sensors that monitor energy and water usage can be used in everything from retail stores and commercial rooftops to commercial and residential landscaping irrigation systems.
  • Disaster prevention. DSSC units have been used to power remote sensors near rivers that monitor potential rising water levels during flood seasons, alert organizations about landslides, and provide other early warnings for natural disasters.
  • Retail store beacons. Retailers can power Bluetooth low-energy (BLE) beacons with dye-sensitized solar cells for in-store monitoring, data, and logistics.

dssc-applications

Dye-Sensitized Solar Cells From Servoflo

At Servoflo, we specialize in offering high-performance solar cells that meet the unique needs and environmental constraints of every client we serve. Our DSSC products are built to provide efficient power even in poor lighting conditions and extreme environments. Contact us today to learn more about our capabilities or to start powering your next project. You can also visit our DSSC page on our website.

Download the Dye-Sensitized Solar Cell Product & Pricing Guide

 

 

 

Why Use Servoflo for Sensors

Posted by Seta Davidian on Feb 10, 2021 9:29:00 AM

Users of pressure and other environmental sensors enjoy a broad selection of models and manufacturers from which to choose. While detailed specifications of individual models are easy to come by, it often helps to understand more about the overall supplier. This blog post explains our approach to helping customers find the best part for their application.

Advantages of Servoflo

air-pressure-pressure-head-resized-600

At Servoflo, we distribute a broad range of pressure sensors, mass flow sensors, humidity sensors and other types from leading manufacturers, including Fujikura, TE Connectivity, Merit Sensors, Metallux and more. Some of our suppliers have no other distribution partners here in North America, giving Servoflo customers unique access to a range of technologies. Our pressure sensor products meet measurement requirements across different price and performance points for pressure ranges from well below 2-inch water column (WC) to several thousand psi for applications in the medical, HVAC, and industrial industries. We also offer a variety of packaging options from board level to completely packaged transmitters. Similarly, our mass flow sensors, humidity sensors and other products go across the price-performance continuum to provide many choices for customers.

Individualized Customer Service

We focus on providing individual attention to meet the unique needs of our customers rather than locking them into a single family of standard products that feature unnecessary features at additional costs. At Servoflo, we proactively start with the question, "What problem are you trying to solve?". From this point, we collaboratively identify for our customers a range of potential solutions from the variety of factories we carry. We discuss with our customers various differences in performance.

Additionally, some of our suppliers provide customers with the opportunity to produce modified sensor designs that fit their specific applications in very low volumes with little to no price premium or expensive upfront investment. This level of customer service and customizing is not available from many large providers (both distributors & large manufacturers).

Greater Flexibility and Added Benefits

In many cases, pressure is not the only parameter requiring measurement. Other critical parameters that may require monitoring include mass flow, humidity, and temperature. We consider all of these factors and more when curating our product selection to offer solutions that meet a broader range of applications at competitive prices. In addition, we can provide benefits like inventory management, stocking, responsiveness, and easy access to technical support.

How We Work Compared to Other Distributors

Active versus passive selling:  Most distributors carry many manufacturers, pick some random parts to put into their stock and passively wait for the right customer to come along. At Servoflo, we communicate with customers directly to proactively match the customer with a range of potential solutions from the variety of factories we carry. We discuss with our customers various differences in performance, features and price to find the best match for their application. Other distributors make the customer dig around their web site, comparing data sheets on their own and often wait to get answers from experts if those experts even exist. Our active approach gives customers a part that meets their needs quickly and accurately. There is no guessing or trying a part that may or may not fit their needs. 

After a correct part has been selected, we can then provide logistical services to ensure that inventory is available for your manufacturing process. Our active approach creates a strong relationship with our customers to allow for adjustments for market changes, parts and product modification, shipping and much more.

Let us know how we can help you by giving us an old-fashioned telephone call at 781-862-9572 or use the contact us button. 

Contact UsOur e-books are a popular way to learn how to pick a sensor!

[eBook Cover] Pressure Sensor Selection Guidemems-3d-1Humidity-Sensor-Guide-1Ceramic-Pressure-3D

 

Topics: Pressure Sensors

High Accuracy Capacitive Pressure Sensors by ES Systems

Posted by Seta Davidian on Feb 1, 2021 11:00:08 AM

ES Systems offers highly accurate capacitive pressure sensors in a variety of packages including a capsule, board level, and transmitter package.

ESCP-MIS1-headerThese sensors are ideal for those looking for extremely high accuracy and stability with media compatibility. In this blog post, we are going to share some key differentiating points of these sensors compared to traditional sensors for high demand applications.

Accuracy & Total Error Band: One of the most advantageous features of these pressure sensors from ES Systems is performance.

Before diving into the details, here is a quick refresher on the difference between total error band and accuracy. Total error band (TEB) is a single specification that includes all sources of error in a pressure measurement, and is it a comprehensive measure of a sensor's true accuracy. Accuracy is a component of TEB which comprises pressure non-linearity, pressure hysteresis, noise, and pressure non-repeatibility.  In addition to accuracy, other possible errors added into TEB include offset, full-scale span, thermal effect on offset, thermal effect on span and thermal hysteresis.

For the various standard ranges from 10 bar to 350 bar, the full-scale accuracy is ±0.125% FS. Next, the total error band is ±0.25%FS from 10 to 100 bar and ±0.5%FS for 200 & 350 bar ranges. Most pressure sensors vary significantly when the total error band is included, if the total error band figure is even provided. Remember that accuracy and TEB specifications are NOT reported in a uniform way. Hence, it is vital for users to read data sheets and the respective fine print very carefully.

High performance and stability is critical in many medical and HVAC applications.

High overpressure: Overpressure tolerance is typically 100x the pressure range. There are very few manufacturers that can provide this high degree of overpressure.

Media compatibility: The seal type and filling oil allow for users to measure the pressures of gases and liquids including harsh media. O-ring options include FKM, EPDM, DBR, VMQ, HNBR. Standard material at the pressure port is stainless steel 316L with an option for titanium or Hastelloy.

Applications: As you can see from these specifications, applications for these sensors are for those needing precise accuracy. The sensors can be oxygen-cleaned if needed. In addition, vacuum measurement can be offered such as -100 kPa to 0 kPa. Here is a summary of models:

 

* coming soon

Get in touch to discuss your application and learn more about these unique sensors?

Contact Us

Topics: Pressure Sensors

How Do Mass Air Flow Sensors Work?

Posted by Seta Davidian on Jan 14, 2021 2:46:26 PM

What Are Mass Air Flow Sensors? 

mass

Mass air flow sensors are detection devices that are used to measure mass flow rate, and they play a critical role in the function of various med

ical equipment. Respirators, ventilators, anesthesia equipment, oxygen concentrators, and many other medical devices rely on mass air flow sensors to monitor and control the flow of air, oxygen, and other gasses for various diagnostic and treatment procedures.  

How Mass Air Flow Sensors Work

Mass air flow sensors detect the flow of gas, air, and oxygen. This data is converted into measurable signals and transmitted to the system’s computer to monitor flow rate, volume, and other important factors. The exact role of a mass air flow sensor depends on the type of equipment it is used in. Common equipment includes:

 

  • Ventilator systems. Mass air flow sensors are used in ventilation systems to monitor the patient’s breathing cycle. The flow of inhaled and exhaled gas is converted into electrical signals, which are transmitted to the processing unit to detect and monitor minute ventilation, inhaled and exhaled tidal volume, and flow rate. This data will help determine any abnormalities.
  • Anesthesia machines. Mass air flow sensors measure the flow of oxygen, air, and nitrous oxide to create the proper gas composition for the patient. It also detects the concentration of anesthetic gas to ensure that the machine administers a safe and effective amount.
  • Oxygen machines. Mass air flow sensors are used to monitor and control air flow rate from the oxygen machine.

How it Works

Mass air flow sensors contain a thermal sensor and a heating source. Once gas begins flowing through the heating source, it transports the heat away, which changes the temperature difference between the heating source and the thermal sensor. This change is used to determine the energy required to maintain the sensor at the same temperature, which is then interpreted into a value. This value is transmitted through a communication interface to calculate flow.

Popular Mass Air Flow Sensor Designs

There are two main types of mass air flow sensors, each of which measure frequency:

  • Analog Mass Air Flow Sensors. Analog sensors produce a variable voltage output.
  • Digital Mass Air Flow Sensors. Digital sensors produce a frequency output.

Partner with Servoflo

Mass air flow sensors are crucial to the accuracy and reliability of various medical equipment. At Servoflo, we offer cost-effective and high-performance mass air flow sensors for our OEM customers. While our primary focus is the medical industry, we are also proud to serve the energy, food and beverage, environmental, machinery, and many other industries. Our high-quality products, commitment to customer service, and expert product design services make Servoflo the ideal supplier for your mass air flow sensor needs.

We have an excellent e-book to help you learn about the key factors of choosing a mass flow sensor.

Discover which Mass Flow Sensor is Right for You

Topics: Mass Flow Sensors

The Differences Between Capacitive & Piezoresistive Pressure Sensors

Posted by Seta Davidian on Oct 19, 2020 8:41:49 AM

This is a guest blog post reproduced with permission from ES Systems, a specialist in high quality pressure sensors for a variety of applications.

The majority of the pressure sensors currently installed in the field are based on MEMS technology and utilize either piezoresistive or capacitive measurement principle. In this article, we will be discussing their main differences and we will be highlighting the advantages of each.

How Piezoresistive Technology Works

The term piezoresistive is composed by the Greek word “piezo” (meaning squeeze or press) and resist. In piezoresistive sensors, four resistors are placed on a silicon diaphragm in order to measure the result of strain or physical pressure applied upon them. Any perceptible change in resistance is being converted, through a Wheatstone bridge circuit into an output voltage. The piezoresistive pressure measurement principle is one of the firstly developed in MEMS technology and it was developed many years before the capacitive one. As a result, it is most commonly used. Due to their widespread and low production cost, piezoresistive pressure sensors are widely used in consumer electronics and the automotive industry, as well as in household appliances.

diagram illustrating how a Piezoresistive sensor works

 

Capacitive Technology Measurement Principle

Two parallel and electrically isolated conducting plates are needed to ensure that a capacitive pressure sensor operates efficiently. The bottom plate is fixed while the top one is sensitive to pressure changes. When pressure is applied, the top plate (or membrane) bends and a capacitance Δ is created. This variation in capacitance is then translated to an electrical signal where it can be read and conditioned by an ASIC or microcontroller.

diagram illustrating how a capacitive sensor works

 

Technology Comparison, Piezoresistive Vs. Capacitive

In comparison to piezoresistive sensors, capacitive pressure sensors offer many advantages. Even though they may require more complex signal conditioning circuits and calibration algorithms, they have higher accuracy and lower total error band. Moreover, capacitive pressure sensors have low power consumption since there is no DC current flowing through the sensor element due to its nature. Thus, very low power sensing systems, can be designed and implemented that require only a small bias to the circuit by an external reader, making them ideal for remote or implanted medical applications. The table below summarizes the pros and cons of the MEMS capacitive pressure sensors with respect to the piezoresistive ones.

Pros Cons
Burst & proof pressure Calibration complexity
Accuracy, total error band Production cost
Power consumption  
Long term stability  

 

 

Typical MEMS capacitive schematic and layout representation

MEMS capacitive pressure sensors also offer excellent long-term stability. This is a design attribute. As illustrated above, a typical MEMS capacitive pressure sensor element features two sense and two reference capacitors. The reference capacitors are not sensitive to pressure variations. The pressure calculation is performed using the following algorithm.

Long term stability is mainly affected by the aging of the sensing elements and therefore the drift in measurement accuracy over time.

Due to the layout of capacitive dies, the sense and reference capacitors are exposed to the same environment. That means that they are exposed to the same conditions and stimuli that cause aging to the sensors and therefore long-term drift. Since the sense and reference capacitors are exposed to the same conditions and are manufactured using the same materials and procedures, they also age with the same rate. Therefore, utilizing the pressure calculation algorithm and the layout of the MEMS die, the long-term drift effect is minimized and therefore an excellent long-term stability is achieved.

Last but not least, the major advantage of MEMS capacitive technology over piezoresistive is the overpressure tolerance (proof pressure and burst pressure). Due to their design, MEMS capacitive sensors can withstand up to 100x the rated pressure. This happens due to the fact that the sensor architecture consists of a fixed bottom plate and a suspended membrane which deforms with pressure. When overpressure is applied the deformation reaches the bottom membrane and inevitably stops without breaking. At the same time due to the distance traveled and the stresses exerted there are no plastic deformations. This translates into an unaffected sensor performance after the release of the overpressure.

Is capacitive technology ideal for overpressure?

As explained above, whenever overpressure is applied to automation equipment, conventional pressure sensors could get damaged. For that reason, sensors based on silicon capacitive process technology could be used. Understanding the advantages of capacitive technology and the various ways it can be applied to pressure sensors is important and could lead to increased productivity and lower maintenance costs. ES Systems has designed pressure sensors with capacitive technology that can offer high performance and precision along with great efficiency and reliability at a competitive cost.

Are capacitive sensors ideal for medical applications?

Medical applications can be enhanced by MEMS capacitive pressure sensors, as they could provide very high accuracy and long-term stability. More specifically, they are extremely tolerant of overpressure, making them suitable for use in applications where measurement safety is critical and sensor repair is not an option.

The cutting-edge MEMS capacitive technology can be applied in demanding environments regarding absolute, gauge, relative, or differential pressure measurements. For this reason, ES Systems offers three families of high-end capacitive pressure sensors for those needing superior accuracy. These families are:

  • ESCP-MIS1, designed to sustain high measurement quality in harsh environments and media. Available now.
  • ESCP-BMS1, ideal for industrial, medical and HVAC applications that require high accuracy and low total error band. Available early December 2020.
ESCP MIS1 header ESCP BMS1 header new
ESCP-MIS1 ESCP-BMS1

 

Want to chat more about pressure sensors? Get in touch to tell us what you need!

Contact Us

 

Topics: Pressure Sensors

ME78X/ME79X Ceramic Pressure Sensors Updated Data Sheets

Posted by Seta Davidian on Sep 25, 2020 10:04:22 AM

Servoflo is pleased to announce updated data sheets for the ME78X and ME79X ceramic pressure sensors from Metallux. These state-of-the-art ceramic pressure sensors have excellent accuracy and versatility for those users designing a pressure transducer or embedding a sensor in a pump, valve or other part of a pressure control system. A notable change is new designs for both the ME78X and ME79X will use an SSOP14 package rather than the previous DFN package.

me78x ceramic pressure sensorThe ME78X are a flush diaphragm, piezoresistive sensor with signal conditioning electronics embedded into the ceramic to provide a 0.5 to 4.5V ratiometric output or I2C output with pressure & temperature information. Calibration can be done in bar (0.5 to 600 bar) or psi (7.5 to 8500 psi). Furthermore, the sensor is available in a variety of configurations including absolute, gauge or sealed gauge. Accuracy choices include high accuracy, standard accuracy, no temperature compensation, or uncalibrated & uncompensated. The ME78X provides incredible versatility for users. The most updated information on the ME78X can be found here.

me790-headerME79X are monolithic piezoresistive ceramic pressure sensors. The Wheatstone bridge is screen-printed directly on one side of the ceramic cell by means of thick film technology and signal conditioning electronics generate 0.5 - 4.5V ratiometric output. Pressure and temperature calibration are done electronically with the on-board ASIC and can be performed in bar (3 to 400 bar) or in psi (50 to 5000 psi).

Electronics provide offset and span correction when the temperature changes. Aging detection is constantly performed. This new method guarantees good precision and long-term stability. The most recent data sheet includes a new mechanical configuration where springs are used for contacts. This innovative methods eliminates the need for soldering, increasing assembly speed, as well as improving ease of assembly resulting in lower overall costs. This mechanical configuration has been tested and validated in the automotive field for many years. Get the most recent information on the ME79X here.

You may notice that the ME78X is flush with a smooth side exposed to the pressure media and the ME79X are monolithic with a small indentation in the middle exposed to the media. Why choose one or the other? If a customer is making an absolute or sealed gauge sensor, then flush mount is ideal as they have a fixed reference. 

Both the ME78X and ME79X have excellent chemical resistance due to the AI2O3 ceramic, making them suitable for nearly all aggressive media.

Do you want to learn more about ceramic pressure sensors? Our e-book is a great place to start!

Download Our Ceramic Pressure Sensor Guide

Data sheet links:

ME78X

ME79X

 

Topics: Ceramic Pressure Sensors, Pressure Sensors

Why Use Servoflo for Board Level Pressure Sensors

Posted by Seta Davidian on Jun 16, 2020 10:02:31 AM

Users of pressure sensors enjoy a broad selection of models and manufacturers from which to choose. While detailed specifications of individual models are easy to come by, it often helps to understand more about the overall supplier. The following blog post compares board-level pressure sensors from Servoflo and other providers of pressure sensors.

Advantages of Servoflo

At Servoflo, we distribute a broad range of pressure sensors from leading manufacturers, including Fujikura, TE Connectivity, Merit Sensors, Silicon Microstructures and many more. Our sensor products meet the board-level pressure measurement requirements across different price and performance points for pressure ranges from 2-inch water column (WC) to several thousand psi for applications in the medical, HVAC, and industrial industries.

By partnering with us, our customers benefit from our:

Individualized Customer Service

We focus on providing individual attention to meet the unique needs of our customers rather than locking them into a single family of standard products that feature unnecessary features at additional costs. Additionally, some of our suppliers provide customers with the opportunity to produce modified sensor designs that fit their specific applications in very low volumes with little to no price premium or expensive upfront investment. This level of customer service and customizing is not available from many large providers (both distributors & large manufacturers).

Greater Flexibility and Added Benefits

In many cases, pressure is not the only parameter requiring measurement. Other critical parameters that may require monitoring include mass flow, humidity, and temperature. We consider all of these factors and more when curating our product selection to offer solutions that meet a broader range of applications at competitive prices. In addition, we can provide benefits like inventory management, stocking, responsiveness, and easy access to technical support like we do.

Sample Overview of Fujikura Sensors

al4-headerFujikura’s AL4 pressure sensor is a low-pressure sensor with digital output. It consists of a silicon piezoresistive pressure sensing chip combined with a signal conditioning integrated circuit. This sensor amplifies the low-level signal from the sensing chip, applies temperature compensation and calibration, and converts it to digital data in proportion to the applied pressure. Highlighted features of this sensor include: 

  • Gauge: positive, negative, or bi-directional
  • Differential: new feature now available!
  • Pressure Ranges: 0–1 kPa (.145 psi) to 0–10 kPa (1.45 psi), depending on model
  • Pressure Media: non-corrosive gases
  • Supply Voltage (constant voltage): 5 +/-0.25 VDC, 3.3 VDC, or 3.0 VDC
  • Accuracy: +/-1.5% FS
  • Ports: dual barbed
  • Size: 11.36 mm x 10.32 mm x 10.32 mm SMT package

Typical uses include battery-operated devices, medical equipment, industrial pneumatic devices, and various consumer devices.

Overview of Silicon Microstructures Sensors

sm933x-headerMEMS pressure transducer technology and CMOS mixed-signal processing come together in the SM9333/SM9336 ultra-low differential pressure sensor. These sensors offer digital, fully conditioned, and multi-order pressure and temperature-compensated sensing. The highlighted features of this model include: 

  • Pressure Range: 125 Pa to 250 Pa differential
  • Digital Interface: 16 bit I2C
  • Compensated Temperature Range: -20° C to 85° C
  • Total Accuracy: +1% full-scale
  • Insensitivity to mounting orientation
  • Robust JEDEC SOIC (16 package with a dual vertical porting option)

Quality Sensors From Servoflo

The above highlighted products are 2 examples of our extensive product offering. We have many more product options that fit a wide variety of needs. High-quality products, individualized customer service, product design flexibility, and a variety of added benefits make Servoflo the better choice for board-level pressure sensors. Contact us to learn more about our board-level pressure sensor solutions or request a quote for our products from one of our experts.

 

Topics: Pressure Sensors