In the world of pressure sensors, users have a broad range of manufacturers and part numbers to choose from. Although detailed specifications on individual parts are easy to come by, we thought it would be nice to provide a comparison between the new AP/AG pressure sensors from Fujikura to various Freescale sensors, including the MPXV7025, MP3V5050(V)/MPX(V)5050(v), MPX(V)5100, and MPX5500. The following summary provides details on how Fujikura pressure sensors offer higher performance and more flexibility for users.

• More input voltage flexibility: All Fujikura AP/AG sensors come in a 3V, 3.3V or 5V supply. The Freescale sensors models listed above come in some but not all supply voltages.
• Pressure range choices: With a broad selection of ranges from +/-100 kPa up to 1000 kPa, Fujikura offers many more choices.
• Customization: In addition, Fujikura is willing to offer custom calibration and custom outputs in quantities that are normally too small for other manufacturers.
• Accuracy: Fujikura offers +/-1.5% full scale accuracy versus +/-2.5% or +/-5% for Freescale pressure sensors.
• Additional models with threshold detection (AP3/AG3) or digital outputs (AP4/AG4) 
• Lower supply current: Freescale sensors require a 10 mA supply current. Fujikura, on the other hand, has a supply current of 3 mA for the 5V supply and 2 mA for the 3V and 3.3V supply versions.

Fujikura's stocking distributor (yes, Servoflo) has over 30 years experience selling and providing technical support for Fujikura pressure sensors.

Typical applications for these parts include sleep apnea, oxygen conservers, blood pressure measurement, ventilators, industrial applications and more.

Our experience over the last 30 years selling Fujikura have shown that these pressure sensors are high quality yet cost-effective for customers. The ability to easily customize sensors for customers' specific needs is a powerful consideration when comparing pressure sensors. We are proud of our relationship with Fujikura and look forward to showing you why!

Quick links:

• AP2/AG2 - analog output
• AP3/AG3 - analog output with threshold detection
• AP4/AG4 - digital output
• Fujikura/Freescale comparison chart
• Fujikura AP/AG pressure sensor overview

The mp6 micropumps from Bartels Mikrotechnik GmbH are suitable for pumping liquids and gases for a variety of different applications. Here we are highlighting the use of the mp6 in a germ detection device used in hospitals.

Bartels and the Austrian Gesundheits-Cluster Oberösterreich worked together with the project goal being the automation of "Genspeed", a medical system for fast diagnosis of hospital germs of Greiner Bio-One International AG. The newly developed on-spot instant diagnosis device "Genspeed R2" is able to verify the existence of different infectious germs - including, among others, antibiotic-resistant bacteria such as MRSA at the human body - from different samples within 75 minutes.

Technological core elements of the device are a microfluidic-chip and a miniaturized automated dispensing system based on the mp6 micropumps. Different reagents can be disposed with microliter accuracy into the inlet opening of the microfluidic chip. The controlled liquid volumes are precisely applied in the correct succession with testing results shown on a computer screen. This method delivers results much faster than the traditional diagnosis chain of sending a sample to a laboratory. This is a perfect example of the capability of microfluidics in respect to optimization of standard processes, reduction of waiting times - and therefore costs - as well as improving patient treatment response times. This system uses 3 mp6 pumps and 1 mp6-oem controller.

Learn more about the mp6 micropump and also try our product & pricing guide for micropumps.

On our Servoflo website, you have likely noticed limited online ordering of pressure sensors. Even though we have a huge offering of pressure sensors from 0.1” to several thousand psi, there are specific reasons why we do not have an online store and parametric search for sensors.

Complexity of pressure sensor part numbers – Have you ever searched for a sensor and become completely overwhelmed figuring out the correct part number to order? Have you ever ordered a part and then realized after your purchase you made a mistake, and then had to order a different part?

Stock – have you had difficulty finding stock of a particular part, and then spent an afternoon browsing, clicking, and sorting through part numbers and manufacturers?

In short, trying to buy pressure sensors online can be a time consuming, frustrating experience. The sheer combination of permutations and combinations of part numbers make for nightmare scenarios for both purchasers and webmasters.

OK, so now after spending an afternoon browsing you may be completely confused by what you saw where. Now that you have come across various pressure sensors options (such as amplified versus unamplified), you may be wondering, what type of pressure sensor do I really need? What does this accuracy spec mean on this datasheet versus this accuracy spec from a different manufacturer? I need a specific package but I don’t see it…Let us show you how to get you out of this mess.

Just the other day, we received a telephone call from a potential customer. After 30 seconds of listening to the customer explain his application, David Ezekiel, our Vice President said, “I know exactly what you need, let me send you the detailed part information.” The customer was very appreciative and thankful for being put in the right direction. We knew how to answer his question because we had experience in his application combined with our vast knowledge of pressure sensors.

So, after you “Google” to find a pressure sensor supplier the next step is to “Servoflo it!”. Find the right sensor for YOUR application quickly and easily by either calling us at 781-862-9572 or emailing your specification through our sensor selector tool. 

UPDATE! Here is a short video clip of our booth and the products we showed! Thanks to Randy Frank at Design World for the video.

From June 25 to June 26, 2014, Servoflo exhibited at the Sensors Expo show in Chicago. We had a great time and thought it would be fun to share a couple of pictures of our booth.

The show was well attended, and booth traffic was busy on both days. We met many new customers interested in a wide variety of our products. Applications ranged from industrial, consumer, medical and more. It was interesting to see how many people traveled to come to the show, which also had many educational sessions. 

We enjoyed exhibiting next to our supplier ZMDI (a supplier of signal conditioning IC's, LED drivers, and power management IC's). Their special pink popcorn giveaway was very popular with booth visitors.

We hope to see you at next year's Sensors Show which will be held June 9 - 11 in Long Beach, California.

You can check out the official Sensors Expo highlights reel here.

(Above image is David Ezekiel of Servoflo providing visitors with sensing solutions!)

Since the end of 2012, Servoflo has been selling the mp6 micropump, made by Bartels of Germany.

This unique micropump focuses on pumping up to 7 ml/min of water and 18 ml/min of air/gas. Other liquids can also be pumped. Typical applications for the micropump include medical drug delivery, cell culturing applications, fuel cells, consumer, nebulizers and much more.

mp6 micropumpThe functional principle is based on a piezoelectric diaphragm in combination with passive check valves. A piezo ceramic mounted on a coated brass membrane is deformed when voltage is applied. By the resulting down stroke, the medium is being displaced out of the pump chamber below. The check valves on both sides of the pump chamber define the flow direction. 

The response to this product has been tremendous, and we are excited about the many new possibilities for this interesting product.

Bartels has release 4 new tech notes to assist customers in their use of the pump:

Amplitude and Frequency Effects on Flow Performance - Based on the diaphragm pump principle, themp6 has a typical flow and pressure performance. By controlling the piezo actuator deflection, the performance can be varied. The amplitude determines the height of the piezo deflection and thereby the displaced volume and the frequency the number of deflections.

Running Multiple mp6 Micropumps - Applications requiring higher flow rates can be done by combining pumps together, in either series for higher backpressure situations (600 mbar for liquid) or in parallel for higher flow rate (about 7 ml/min per pump for water).

Media Compatability of the mp6-pp - The mp6-pp is a polypropylene version of the micropump. This table shows the chemical resistance of the polyproplyene for different media.

Viscosity Effects on Pump Performance - This note discusses the effect of different viscosities on pump flow and pressure performance.

In addition, there are many other application notes and demonstration videos which may be of interest. 

See a listing of all application notes

Check out video demonstrations of the mp6 pump

Review technical specifications of the mp6 micropump

InControl Medical, located in Wisconsin, is a medial equipment company offering solutions for female urinary incontinence, a common problem among women, particularly after childbirth. At least 20% of the female population in the United States experiences this problem. Previous offerings to solve this health problem were uncomfortable, yielding poor results that often lead to invasive surgery to correct the pelvic floor.

In response to this problem, InControl Medical created InTone, which combines electrical muscle stimulation and biofeedback to create a non-invasive home-use solution offering more comfort, better tracking, and thus improved results for patients. The patented probe, shown below, contains a small pressure sensor that measures the change in pressure inside the probe when the muscle contracts against it. This data is tracked in the handheld control unit that acts as a portable therapist, guiding the patient with visual and audible instructions to ensure exercises are done correctly. Precise gains in pelvic floor muscle strength are documented in one one-hundredth of a pound per square inch. Each session is date stamped and weekly averages are calculated to compare against previous weeks, thus allowing health care providers to follow the patient's progress.

About the pressure sensor

When selecting a pressure sensor, InControl turned to Servoflo to assist in finding a solution. After evaluating their application requirements, Servoflo suggested trying the SLP33A Pressure Sensor Series, a high performing gauge pressure sensor with a 0-2 psi range and a linear 0.5 to 4.5 volt output. Because the temperature range in the application is narrow, InControl is able to optimize the output resolution and accuracy to provide data to one one-hundredth of a pound per square inch. This pressure sensor also accepts a low power supply of 2.2V to 3.3V and a small size of 10 mm X 8.6 mm, making it a perfect fit for portable medical applications. The pressure sensor is available as a 6 pin dual-in-line package or surface-mount. The high performance combined with low cost made it an ideal choice for InControl Medical. Obtain detailed specifications about the SLP33A pressure sensors.

To learn more about InControl Medical, please visit their website at www.incontrolmedical.com.

To learn more about pressure sensing solutions from Servoflo, please visit www.servoflo.com. Servoflo is a provider of pressure sensors, humidity sensors, sensor signal conditioners, and LED drivers for the medical, process control, HVAC, automotive and other industrial applications. 

Sorry to have been missing in action on our blog!!

We have posted a new white paper on our web site written by David Grice of ZMDI. The article, published in Sensors Magazine, is titled, "Optimizing the Calibration of Sensor Interfaces With Built-In Correction Algorithms". Here is an abstract of the article with a complete link to download.

Sensor signal conditioners with built-in correction algorithms can greatly aid sensor system designers as long as they understand which algorithm to use and when. The perennial challenge for sensor interface designers is to calibrate and correct the inherent nonidealities present in transducers. The major contributors to nonideality are typically the nonlinear response to stimulus, the offset, and the temperature dependence of one or both of these factors. The advent of commodity IC's with high-performance analog and complex digital circuitry reduces the effort and cost of sensor correction and provides the designer with systemic methodologies and tools for sensor correction. This article examines these techniques and describes how to optimize them for one broad class of sensor signal conditioners that are inexpensive yet highly configurable, enabling high-precision measurements made using a range of sensor types.

You may download the complete white paper here. No sign up necessary!

When designing a new product, looking for components can be daunting. Often times, designers must decide whether to purchase an off-the-shelf pressure sensor or design their own. This post helps clarify the criteria designers can apply when making this important decision.

• What do I need from the total SYSTEM perspective? Look at the overall product by reviewing total performance requirements, the market and applications. How does this affect component selection?
• How quickly will begin sellingyour product?
• What skills do you have within your organization? What skills do you need to outsource? For example, do you have electrical and mechanical engineering skills residing within your organization? If you do, are they accessible and available for design assistance? If you need to look elsewhere, do you have a qualified resource to utilize?
• Do you have the equipment necessary to calibrate your own transducer? Typical equipment needed are temperature, pressure and humidity tools to modify the environment for calibration. Are there people available to calibrate your designed sensor?
• There are additional logistical issues to consider. For instance, what is your annual requirement of sensors? What is your time-to-market and cost targets? Where are you manufacturing? Are there any proprietary issues to consider? How many sources do you need?

By reviewing these questions, the path to deciding between make versus buy becomes much clearer. You should buy a complete transducer if you are resource-limited and have a fast-time to market requirement. Lower volumes typically under 25,000 sensors per year do not usually warrant the investment in making your own transducer. Above this quantity, return on investment on internal resources is improved and may be something to consider.

Let's take a look at a specific example by evaluating the following situation. 

An application has a requirement for a calibrated, temperature-compensated pressure sensor that measures up to 30 psi. An amplified, off the shelf solution has a cost of between $6-7 each at 1,000 pieces, with a 1.5% to 1.8% accuracy over a broad temperature range. A fully packaged solution also translates into fewer parts to buy and stock.

To create the same transducer internally, the cost of an unamplified, uncalibrated pressure sensor plus additional op amps and signal conditioning to calibrate for span and off-set would cost in parts approximately $2-3, not including assembly labor and calibration time. Perhaps your accuracy requirements are not as stringent as 1.8% over a wide temperature range or there are packaging issues to consider. Another consideration to think about, if you are utilizing a contract manufacturer, there are typically assembly charges per component so the additional insertion of perhaps 6 components could affect assembly costs.

If your volumes are very high, investment in automated, more sophisticated calibration equipment can reduce labor time and costs and have an attractive return on investment.

Our team of experts combined with a broad selection of pressure sensors (both unamplified and fully packaged) and signal conditioning parts can guide you through this process. Our huge offering ensures that a solution can be found for you, regardless if you make or buy.

To get started, the best use of your time is to take advantage of the Sensor Selection Tool. We can then provide you with informed, detailed options for your consideration at no obligation to you. We view our role as a design resource to find you an optimal solution for your design.

Access the Sensor Selector Tool here

Review our Transducer Design Guide which includes typically sensor elements and signal conditioning for making your own pressure transducer.

Sensor technology has changed dramatically over the past few years. Previously, customers purchased the sensor elements and electronics and calibrated a sensor themselves. The development of improved electronics, MEMs technology and efficient manufacturing technology has created a new humidity sensor market - fully calibrated humidity sensors with an I2C output. Many companies are offering models with similar features.

Yet, price and performance does vary significantly between models, making it important for users to understand the the performance of a humidity sensor over the entire range. This data is often well hidden in fine print in data sheets.

IST, the supplier of our HYT digital humidity elements and the new sensor elements P14, tested 4 different humidity sensors at 85% rH @ 30C for 65 hours. 2 competitors, the HYT271, and the P14 humidity element were tested. The 2 competitors units showed a 1.25% and 2.5% deviation in readings compared to only 0.17% for the HYT271 and 0.09% for the P14.

What does this mean for designers trying to choose a humidity sensor? The humidity sensor element (such as P14) plays a critical role in the performance of a fully integrated and compensated humidity sensor. Electronics is limited in compensating for poor signals a sensor element sends. The combination of good sensor elements and electronics is the key to sensor design.

The integration of a sensor element and electronics is fairly straightforward. However, if performance over time and at extreme conditions is critical for your application, take the time to research the quality and stability of the sensor element used. Saving a little in upfront component cost could end up costing you much more in the long run!