Seta Davidian

Recent Posts

How to Use a Gauge Pressure Sensor to Measure Negative Pressure

Posted by Seta Davidian on Apr 27, 2023 11:26:00 AM

There are two types of pressure sensors used for negative pressure or vacuum pressure applications: gauge sensors and absolute pressure sensors. The reference pressure is the differentiating factor between these 2 types of sensors. The diagram below illustrates how the different methodologies work.

measuring negative pressure using a gauge pressure sensor



In applications that rely on the principle of a vacuum, it is important to effectively measure negative pressure (also known as vacuum pressure). There are two basic ways to do so:

  • Measure the amount of pressure below local atmospheric pressure [typically 14.7 pounds/ square inch absolute (PSIA)]
  • Measure how much pressure is above absolute zero vacuum (0 PSIA)

Both methods of measurement utilize the same scale and pressure point. However, these two measurements will yield differing results over time because one measurement's reference point is a fixed quantity (absolute zero vacuum), whereas the other relies upon a variable amount (atmospheric air pressure, which can fluctuate).

  1. In the case of a gauge sensor, either a single port or dual port model can be used. In the case of a dual port gauge sensor, the "lower pressure" port measures the negative or vacuum pressure.
  2. By accessing the "lower pressure" port, the user is mimicking applying positive pressure to the higher pressure port as in pressure range.
  3. The advantage of using a gauge sensor is if the user wants to measure a vacuum smaller than the full vacuum range 14.7 psi, such as -3 psi, using a lower range focusing on the negative pressure range is more appropriate. This way, by using a smaller full-scale range pressure sensor, the user captures the full-range of the vacuum pressure measurements, thus obtaining more resolution and more design flexibility. For a single port gauge sensor, the single port is vented to the atmosphere.

For example, if a user is trying to measure the inhalation pressure in a respiratory application, the pressure range would be no more than 0.6 psi. If an absolute pressure sensor is used, only 4% of the pressure range would be used, hence wasting 96% of the sensor's calibrated range. By using a gauge sensor such as the AL4 Series, the user can capitalize on higher resolution and measure smaller negative pressure ranges.

Measuring Pressure Below Local Atmospheric Pressure Sources

Vacuum pressure is typically measured in terms of psi or pounds per square inch vacuum (PSIV). This measurement is generally relative to the surrounding atmospheric pressure. Vacuum pressure transducers can convert the inner negative pressure contained by an application into an electrical signal, and from there into a precise measurement.


At 0 PSIV—which is the same as typical atmospheric pressure, or 14.7 PSIA—the electrical output of a vacuum pressure transducer is 0 VDC. At full-scale, vacuum (14.7 PSIV or 0 PSIA), the output generally increased to about 5 VDC. A vacuum pressure transducer's output in volts increases proportionally to the increase in vacuum or negative pressure. On the other hand, an absolute pressure transducer emits increased positive voltage in proportion to decreasing vacuum.

Measuring How Much Pressure is Above Absolute Zero Vacuum Sources

The scale for absolute pressure begins at the high vacuum point of 0 PSIA. Unlike measurements that rely on atmospheric pressure as their main reference point, this methodology allows for more consistent readings.


An absolute pressure transducer features an electrical output of 0 VDC at 0 PSIA and increases to 5 VDC when it reaches full-scale pressure (14.7 PSIA). This output is expressed in positive voltage.

Pressure Sensors that Measure Negative Pressure

Vacuum pressure transducers and absolute pressure transducers measure the same thing using different points of reference. They are both crucial components for use in applications that require accurate and reliable negative pressure measurements for proper functionality and optimal performance.


When attempting to measure negative air pressure, it's important to use the proper equipment and to have that equipment calibrated to yield correct readings. Even small discrepancies between measurement and actual vacuum level could lead to performance issues.

Examples of classic applications where negative pressure measurements are needed include negative wound pressure therapy, breathing applications, pump control/performance monitoring, HVAC applications such as filter monitoring, and pressurized rooms such as cleanrooms and isolation rooms. One pressure sensor series which works well for these applications is the AP/AG Series from Fujikura.

To learn more, we have an e--book, How to Pick a Pressure Sensor.

[eBook Cover] Pressure Sensor Selection Guide

At Servoflo, we are an industry-leading supplier of high-quality pressure sensors, environmental sensors, and micropumps  Our many years of expertise allow us to provide detailed and practical assistance for engineers designing new components. 

If you are in need of exceptionally precise and reliable sensors for negative pressure applications, then utilize our pressure sensor selector tool to tell us about your specific needs. Our team will then suggest specific parts for you to review

Pressure Sensor Selector

Topics: Pressure Sensors

When to Use MEMS Capacitive Pressure Sensors

Posted by Seta Davidian on Jan 30, 2023 11:27:09 AM

Various technologies are used to make pressure sensors. 2 of the most common include piezoresistive and capacitive pressure sensors. Both can be used for gauge, differential, or absolute pressure measurement. While piezoresistive is found in low-cost sensors, there are situations where a capacitive pressure sensor is better suited for the application.

In capacitive pressure sensors, the electrical capacitance changes with pressure. In simplified terms, this change in capacitance is measured and converted to a pressure measurement. This capacitive element technique creates a pressure sensor with key advantages, including:

Robustness: Capacitive pressure sensors can easily withstand high-proof pressures and overpressure.

Temperature performance: These sensors can operate over a wider temperature range than traditional piezoresistive pressure sensors. 

Power consumption: Capacitive pressure sensors use low power because no bias is required to operate the sensor.  This feature makes the sensors suitable for IIOT products where power use is critical. The sensors can be operated in extremely low power modes until activated when needed.

Accuracy: Low hysteresis, high repeatability and low sensitivity to temperature changes allow for highly accurate sensors. 

Long-term stability:  Minimal drift gives users superior long-term stability over other pressure sensors.

Newer packaging styles: Capacitive sensors have become much smaller compared to older generations which resembled a brick.

Because the production and calibration costs of capacitive sensors are higher, it is not expected to act as a replacement for lower-cost piezoresistive pressure sensors. Instead, these newer generation capacitive sensors open up opportunities for pressure measurement that cannot be done with piezoresistive pressure sensors. Some sample applications include: 

furnaceProduction Equipment: Automated pumps and valves need to be monitored for pressure. A capacitive sensor has the safety to be exposed to harsher environments.

Industrial Filter Monitoring:  Differential pressure measurement is required to monitor filter clogging in industrial equipment. The capacitive sensor offers excellent overpressure tolerance (typically 100 times) and has a minimum in-line pressure drop requirement.

Powerless Pressure Monitoring System: Due to its nature, a capacitive pressure sensor does not require DC bias for its operation, minimizing power requirements, and allowing the user to set up remote wireless monitoring.  Wireless level tank monitoring can be done by creating a sensor network with data sent to the cloud. The excellent overpressure tolerance and high accuracy combined with the low power requirement make the capacitive pressure sensors a unique solution to solving difficult pressure measurement situations.


To learn more about the advantages of capacitive pressure sensors, check out these blog posts:

Learn the Differences: Rated Pressure, Overpressure, and Burst Pressure


If you are not sure what kind of sensor you might need, take advantage of our pressure sensor selector tool, and we will then provide you with specific options for your application!

Pressure Sensor Selector

Topics: Pressure Sensors

Converting Air Velocity Measurements to Volumetric Flow Rates

Posted by Seta Davidian on Dec 15, 2022 11:47:16 AM

This blog post is courtesy of European Sensor Systems (ES Systems), a provider of highly accurate pressure sensors and mass flow sensors. 

How do you convert an air velocity measurement to a volumetric flow rate? It is important to understand the various formulas and technical definitions to prevent errors in calculation. 

Volumetric flow rate is the volume of fluid that passes per unit of time.

Flow meter technologies such as differential pressure, magnetic, thermal, turbine, ultrasonic, and vortex all measure flow rate as a function of fluid velocity. Please refer to the respective flow meter datasheet for detailed information and specifications.

You can calculate the volumetric flow rate by using the equation shown below:

volumetric Flow Rate (Q) = Flow Velocity (V) × Cross-sectional Area (A)


Q is the Volumetric Flow Rate in m3/s

V is the Flow Velocity in m/s

A is the cross-sectional area in mm2

flow rate and flow velocity diagramFor example, if a gas had a velocity (V) 15 m/s and was traveling through a pipe of 20mm inner diameter then the volumetric Flow Rate (Q) would be 0.004712 m3/s which is equal to 282.74 l/min.

Converting velocity to mass flow rate

Similarly, the volumetric flow rate can be converted to the mass flow rate if the density of the gas measured is known.

Volumetric Flow Rate (Q)=(Mass Flow Rate (ṁ))/(density (ρ))Where,

ṁ is the mass flow rate in kg/s

ρ is the density in kg/m3

From the two equations above it can be derived that:

Mass Flow Rate (ṁ) = V × A × ρ

Using the same example as above, if the density was 998 kg/m3 then the volumetric flow rate of 282.74 l/min would be equivalent to a mass flow rate of 4.703 kg/s.

Velocity profiles – Laminar & turbulent flow

Laminar flow is described as fluid particles following smooth paths in layers, with each layer flowing smoothly past the adjacent layers with little to no mixing in fluid dynamics. The fluid continues to flow without lateral mixing at low velocities, and neighboring layers float past each other like playing cards.

Turbulence, also known as turbulent flow, is a fluid motion characterized by chaotic variations in pressure and flow rate in fluid mechanics.

laminar and turbulent velocity profiles

Laminar flow can be, in general, achieved by providing a 20x the internal diameter of the tube used straight tube length in upstream and downstream flow. For example, if a 25mm ID tube is used, if you connect a 50cm straight tube upstream and downstream of the flow meter, you can expect a laminar flow.

In most applications, turbulent flow is present in the application. This increases the flow noise observed by the flow meter.

Volumetric & mass flow rate units

Volumetric flow rate can be expressed in a variety of units with the most common being m3/s, m3/min, m3/h in metric units and the respective imperial units. Volumetric flow rate is also typically expressed in l/s, l/min, l/h.

Mass flow rate is usually referenced in kg/s, kg/min, kg/h in metric units and in lb/s, lb/min, lb/h in the respective imperial units. Mass flow rate can be also expressed in l/s, l/min, l/h but with one condition.

Due to the fact that for mass flow measurement the gas density must be taken into account, when using l/min unit for mass flow, the temperature and pressure reference conditions must be noted.

There are two common reference conditions for mass flow measurements. These are:

  • Normal, expressed at 0oC temperature and 1013 mbar pressure and denoted as ln/s, ln/min, ln/h
  • Standard, expressed at 20oC temperature and 1013 mbar pressure and denoted as ls/s, ls/min, ls/h

Converting mass flow from reference to ambient conditions can be achieved using the following formula:

〖Flow〗_ambient=〖Flow〗_reference×〖Pressure〗_reference/〖Pressure〗_ambient ×〖Temperature〗_ambient/〖Temperature〗_referenceWhere:

  • Pressure is in mbar
  • Temperature is in Kelvin

Converting differential pressure to flow velocity

Before going into how to convert differential pressure to flow velocity, it is important to note the definitions of static, dynamic, and total pressure.

What’s pressure?

The constant physical force exerted on or against an object by something (such as air) in contact with it is known as pressure.

What’s static pressure?

The pressure you get when the fluid isn’t flowing or when you’re moving with the fluid is called static pressure. While now moving, air would press against you equally in all directions. Because of the conservation law, static pressure decreases as the speed increases.

What’s total pressure?

The pressure a fluid exerts when it comes to a full stop is known as absolute (or total) pressure. When you face the wind and the air collides with your body, total pressure acts on you.

What’s dynamic pressure?

Dynamic pressure is the pressure exerted by a fluid as it travels. It refers to the difference between total and static pressure.

In order to measure flow via differential pressure, a deliberate obstacle has to be introduced in the flow line in order to impose the increased differential pressure measurement. The obstacle can be anything, from an orifice to a simple narrowing of the tube.

Using Bernoulli’s principle, you can correlate flow velocity with differential pressure using the following formula:

using bernoulli’s principle to corelate flow velocity with differential pressure 

Measuring velocity and airflow


  • ESCP-BMS1 – a series of board mountable pressure sensors for applications requiring high resolution and accuracy. Total error band of 0.25% FS from 0-60C.
  • ESRF-ESF – an inline gas flow sensor based on the hot-film anemometer principle for mass gas flow measurements.
  • ESRF-HF – a family of insertion gas flow transmitters based on the hot-film anemometer principle for mass gas flow measurements.

We are here to answer further questions you may have. Contact us to tell us what you are looking for!

Contact Us

Electronic Manufacturing Services from Metallux Specializes in Hybrid Circuits and Power Modules

Posted by Seta Davidian on Sep 27, 2022 10:13:12 AM

Metallux of Switzerland is expanding its offering of electronic manufacturing services. These state-of-the-art manufacturing and engineering services help customers get to market quickly. Reliability and flexibility allows Metallux to engineer, prototype, and produce over 4.5 million products every year.

Services include:

Electronic assembly & manufacturing Encapsulation & coating on various substrates
Reliable hybrid circuits Finishing & injection with coatings, epoxy, silicon, resins
Multi-layered hybrid circuits with integrated components Automated inspection & testing
Automated & manual screenprinting lines Climatic chambers for calibration
Laser trimming

X-ray & AOI testing

SMD, chip-on-board & reflow line EMC compliance testing
Active & passive SMT, from 0402 to BGA and μBGA End-of-life & test equipment for QA
Chip & wire: die attach, wedge & ball bonding Production, assembly & packaging in a DNA-free environment



To help better understand the capabilities available, here is a Q&A about these Metallux services.

What experience does Metallux have with power hybrids?

Metallux has long-term knowledge about chip & wire processes to interconnect bare chips to several types of different substrates by wedge & ball bonding. In the last two years, Metallux technicians attended several courses and learned relevant information about recent developments in the same processes for power dies.

What technologies and processes does Metallux have for the production of power hybrids and what investments are needed to produce them?

Metallux has many years of experience in screen printing on ceramic (alumina) and metal (steel) substrates, soldering, and various wire bonding techniques including standard hybrid technology (A12O3), thick film technology, die-bonding, standard wire bonding, and more. We have invested heavily in any additional processes and equipment necessary for power modules and expect to be able to produce samples in 2023. The same equipment can also be used for producing several tens of thousands of power devices.

What kind of information does Metallux need from the customer to provide samples?

Standard information such as application details, technical specifications, environmental situations, commercial (price target, quantities, desired production schedule), specific technology required, and reason for inquiry. For example, if there already is an existing supplier, what are the current stumbling blocks? In addition, we would also need a BOM, schematics, dimensions, operating temperature range, operating voltage, operating current, and power dissipation.

Learn more about hybrid circuit & power module manufacturing from Metallux.

Learn More About Manufacturing Services From Metallux


Topics: Pressure Sensors

Learn the Difference: Rated Pressure, Overpressure & Burst Pressure

Posted by Seta Davidian on Nov 12, 2021 12:45:18 PM

In many applications and industries, it is not uncommon to come across the risk of excessive pressure, or overpressure, within the pneumatic or hydraulic network of equipment, especially in facilities with a high degree of automation. If this phenomenon is not controlled properly, it may cause permanent damage to equipment and production lines which is why pressure sensors are commonly used as some form of protection in several operations such as industrial, medical, bioprocessing, and pharmaceutical.

ESCP-MIS1-headerNevertheless, pressure transducers are not always able to handle extreme levels of pressure. In order to survive extreme pressures, engineers and designers have defined pressure ratings that can describe the conditions a pressure component can withstand without affecting its operational performance. These are divided into:

            • rated pressure
            • overpressure
            • burst pressure

The maximum pressure that the manufacturer assigns as the desired pressure at which a device will function properly is normally outlined as rated pressure. An overpressure value is a condition where the pressure transducer can withstand excessive pressure without affecting performance or compromising subsequent measurements. Often overpressure is mistaken for burst pressure, which is defined as the maximum pressure that can be applied without physically damaging the body of the sensing component.

For example, if a pressure sensor has 2 bar rated pressure, 5x overpressure, and 10x burst pressure, this means that the sensor can measure pressures up to 2 bar, it can withstand overpressures up to 10 bar without being damaged, and if the pressure reaches 20 bar the sensor sealing will burst. From 10 to 20 bar, the sensor does not burst but it is damaged and will not operate as expected.

What can cause overpressure?

Different factors can trigger overpressure, including unintentionally increased heat, uplift, a faulty pressure regulator, process synchronization, or an amalgamation of all these factors.  These causes are common in industrial applications where there are solenoids, centrifugal pumps, regulators and valves.

How capacitive sensors can prevent catastrophic failures due to overpressure

Due to their design and measurement principle, MEMS capacitive pressure sensors can handle up to 100x overpressure, making them the only available sensor technology in the market that can withstand high overpressure.

The overpressure tolerance along with the excellent accuracy and total error band specification make capacitive sensors ideal for any application that uses pumps or valves, especially in automation equipment, where overpressure is frequently experienced. 

Before selecting a sensor, the maximum pressure value needed for the application should be taken into consideration. Understanding the advantages of each technology, the dynamics of their system, the limits of the sensor, and the various ways it can be applied are important to increase productivity and lower maintenance costs.

In the following figure, you can see an application example of the overpressure performance of a 10 bar absolute calibrated sensor from ES Systems. The sensor's maximum expected operating pressure (MEOP) is 10 bar. The sensor is measured at a reference pressure of 9.3 bar absolute and then pressurized at the following pressure steps as seen in the graph below.


As predicted, the sensor returns to nominal performance even with 100x overpressure is applied for a long period of time. 


Contact Us


Topics: Pressure Sensors

Pressure Sensors for Medical Ventilators

Posted by Seta Davidian on Jul 8, 2021 4:04:35 PM

Medical ventilators supply air or other gaseous mixtures to patients through the use of pressure. These devices are used when patients require assistance breathing or are entirely unable to breathe on their own. One vital component that these systems use to function is a pressure sensor.

In this blog post, we'll review how medical ventilators work and the role that pressure sensors play in the functionality of these devices.


How Does a Ventilator Work & When Are They Used?

Hospitals often use medical ventilators as life support devices for patients who are either unable to breathe on their own or experience difficulty breathing. There are both invasive and non-invasive ventilators available. While noninvasive ventilators use an airtight external mask, invasive ventilators involve inserting internal tubes via tracheostomies or intubation.

Medical ventilators are normally used as a temporary measure to assist with breathing for a limited time, such as when a patient is undergoing surgery. Anesthesia may slow patients' breathing, warranting the use of a ventilator throughout a surgical procedure. In some cases, patients with serious medical conditions that affect their breathing may require ventilation during the recovery process, usually while receiving treatment in a hospital's critical care unit (CCU) or intensive care unit (ICU).

Other conditions that may require the use of a ventilator include acute respiratory distress syndrome (ARDS), pneumonia and other respiratory infections, lung diseases, brain injury, drug overdoses, or strokes. 


Where Are Pressure Sensors Used on a Ventilator?

Pressure sensors are integral to medical ventilators. Depending on the type of system, medical industry pressure sensors are used in several places on a ventilator, including:

  • Measurement of the pressure between the regulator and filter from the starting oxygen and air inputs
  • Measurement of pressure when the patient inhales, along with the pressure of the gases leading to external humidifiers
  • Measurement of pressure when patients exhale into medical ventilators
  • Measurement of barometric pressure to offset changes in elevation

Depending on the role of a pressure sensor in a ventilator, several sensor solutions are available for different applications. These include filter monitoring, airflow control, O2 flow control, O2 source pressure, CO2 level, and humidifier solutions. 


Pressure Sensors from Servoflo

Based on what our customers require for their medical ventilators, Servoflo offers multiple pressure sensor solutions. Our pressure sensors meet various measurement requirements across multiple performance and price points. We have compiled a detailed list of sensor suggestions for medical ventilators which can be found here.

Servoflo offers pressure sensors ranging from under 2-inch water column to as much as several thousand psi in a variety of packages and configurations. In addition to top-quality pressure sensor products that work with medical and other applications, we can provide individualized customer service to ensure our customers get the most from their products.

When you work with the professionals at Servoflo, you'll benefit from increased flexibility and other advantages. For example, we consider other critical parameters that may need consistent monitoring such as humidity, mass flow, and temperature. Regardless of what you require for your systems, we have the resources and expertise needed to provide the right solution.

For more information about our selection of pressure sensors for all medical applications, please visit our medical equipment page.

Adapting Pressure Transducers for Your Applications

Posted by Seta Davidian on Jul 1, 2021 9:44:46 AM

Choosing the right pressure transducer for a specific application can be overwhelming. There is a vast array of choices, many of which duplicate performance. If you don't find the right combination of features, many manufacturers don't offer modifications or customizations without a large order. That leaves you with little choice but to try to make do with the closest fit. 

Screen Shot 2021-07-01 at 9.41.44 AM

To combat this, Servoflo has been offering services to help companies solve their pressure sensing measurement needs for over 30 years. Our customers don't have to make do with the closest available option. We offer many customizations to fit the needs of their pressure transducer applications, regardless of order size. 

Customizations and Requests Servoflo Can Help With

A custom pressure transducer is manufactured with specifications to fit a particular non-standard application. Servoflo is proud to offer modifications or customizations for special features on our pressure transducers. Our strong, long-term factory relationships enable us to provide pressure transducer customizations and special requests relatively quickly and easily. We work directly with your engineering team to produce a pressure transducer that meets your most demanding specifications and requirements.

Our custom engineered pressure transducers are made with the utmost engineering design expertise and quality manufacturing capabilities. We offer the following special requests and customizations:

  • Electronic connections
  • Full or partial housing
  • Measurement parameters, including pressure range and calibration accuracy
  • Process fittings 
  • Wetted materials, such as seals and housing materials

Standard Packaged Transducers from Servoflo

Servoflo is committed to offering the widest choice of standard packaged transducers representing a wide variety of price/performance variations. Some of our featured sensors include:

  • Anfield Sensors. Anfield Sensors Inc. is an industry-leading manufacturer of pneumatic and hydraulic sensors known for faster delivery and industrial performance. They specialize in vacuum, differential, pressure, and temperature switches and transducers for the foodservice, industrial, medical, military, and mobile industries.
  • American Sensing. Our newest line focuses on high accuracy, high temperature, and low power supply for IIoT applications. American Sensing provides vast experience in sensing technologies and manufacturing, and they deliver cost-effective solutions for the aerospace, industrial, and military industries, as well as many other demanding applications.
  • Microsensor. Micro Sensor Co., Ltd. is known for its variety of product options. They are leading manufacturers of level sensors, pressure sensors, and pressure transmitters. Their products are differentiated by their features, including data collection through a bus, digital wide temperature compensation, and non-linearity correction. 

Servoflo: Providing High-Quality, Cost-Effective Solutions for Over 30 Years

Servoflo has been an industry-leading provider of pressure sensors, mass flow sensors, oxygen sensors, micropumps, and humidity sensors for over 30 years. We serve a vast array of industries, including automotive, consumer, HVAC, industrial equipment, and medical. Our customers know that they can depend on our in-house technical support and FAE resources to ensure the optimal sensor choice for their application. 

Servoflo provides only services and products that offer the highest value and reliability for customers across diverse industries and applications. Our team has a wealth of in-depth expertise for client businesses to draw upon when designing their solutions. For more information, contact us today or request your customized pressure transducer online.

Request Your Customized Pressure Transducer

Barometric Sensors 101

Posted by Seta Davidian on May 24, 2021 1:14:59 PM

What is a Barometric Pressure Sensor?

SOP30DA barometric pressure sensor is a new type of barometer that measures atmospheric pressure. They are commonly used for weather measurement, altitude compensation, dive watches, altimeters, underwater equipment, and much more. At Servoflo, we offer a wide range of standard and compact barometric pressure sensors suitable for a wide range of applications.


How Does a Barometric Pressure Sensor Work

In older sensors, barometers used liquids to measure atmospheric pressure. One of the oldest types of barometers used mercury, which would raise or lower within a column in response to pressure changes. As technology advanced, the aneroid barometer was invented. This type of barometric pressure sensor utilizes an aneroid cell that expands or contracts when the atmospheric pressure changes. This movement causes the levers to amplify, which results in display pointers indicating the pressure reading on the front display. 

Many of today’s modern barometers utilize microelectromechanical system (MEMS) technology, making them capable of measuring pressure in a more compact and flexible structure. This allows them to be used in smaller applications such as mobile devices and watches. A MEMS barometric pressure sensor detects atmospheric pressure based on how it affects its diaphragm. The more the diaphragm deforms, the higher the pressure.

Applications For Barometric Pressure Sensors

Barometric pressure sensors are used in a wide variety of applications including:

  • Predicting weather. The most common application for barometric pressure sensors is monitoring and predicting weather conditions. Even tablets and mobile devices come equipped with barometric pressure sensors that give users immediate insight into local weather conditions.
  • Altitude compensation. Higher altitudes can affect the measurement of various environmental parameters and overall performance of various equipment such as medical devices, consumer equipment and much more. Barometric pressure sensors can provide the altitude compensation needed for other types of sensors and equipment to function properly.
  • Navigation. Barometric pressure sensors are utilized for navigation purposes using the altimeter function, which enables accurate vertical positioning. For example, it helps when you are climbing between floors or up a mountain.
  • Devices that monitor physical activity. They are used in devices that monitor physical activities in wearable devices. This helps the wearer more accurately track activity via air turbulence instead of just steps.
  • Drones. As more and more applications adopt drone technology, barometric pressure sensors become very important in measuring precise altitude and air pressure on these devices.

Servoflo Barometric Pressure Sensors

ams6915-headerServoflo offers a wide variety of barometric pressure sensors to suit the needs of numerous applications. 

With over 30 years of experience finding solutions to various design challenges, we have the necessary skills to provide barometric pressure sensors that suit your requirements. For help choosing the best barometric pressure sensor, contact us to discuss your application today or review our barometric product and pricing guide.

Download Barometric  Product & Pricing Guide

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.


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.


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 the 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:


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.